Arctic Sea Ice : Forum

Cryosphere => Arctic sea ice => Topic started by: wanderer on March 19, 2013, 12:05:12 PM

Title: "Stupid" Questions :o
Post by: wanderer on March 19, 2013, 12:05:12 PM
I think a topic like this is necessary, so amateurs like me won't spam other topics or slow down the great work experts here are doing. 

So every "stupid" :o question should be asked here:

I'm starting:

When does melt season normally kick in?
Tomorrow is  March Equinox  http://www.timeanddate.com/calendar/march-equinox.html (http://www.timeanddate.com/calendar/march-equinox.html)   
- is this the official beginning of melt season 2013?
Title: Re: Stupid Questions :o
Post by: Neven on March 19, 2013, 01:28:16 PM
Welcome, wanderer. I'm an expert in (asking) stupid questions.

I don't know about an official definition, but for me the melting season starts as soon as total sea ice area/extent has reached a maximum, in other words when the trend lines on these graphs (https://sites.google.com/site/arcticseaicegraphs/) peak. During the first subsequent weeks area and extent decrease is slow, but in May the melting season starts in earnest, switching to high gears in June, July and the first half of August.

Mind you, it's good to remember that a large part of the ice pack continues to thicken for several weeks after the area/extent maximum was reached. That's because ice may melt at the edges because of the arrival of the Sun, but the further you go towards the North Pole the longer it takes for the Sun to start shining there every day to cause more melting than the ice can thicken.
Title: Re: Stupid Questions :o
Post by: OldLeatherneck on March 19, 2013, 05:19:32 PM
On more than one occasion, I've seen so-called "Stupid" questions cause the "Briliant" people to identify solutions to critical problems.  In almost every "Brainstorming" session that I ever facilitated, it was "Off-the-Wall" or "Out-of-the-Box" ideas and/or comments that led to concrete proposals or solutions.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on March 19, 2013, 06:23:12 PM
OLN.....Absolutely agree. I have been facilitating problem solving groups for nearly 15 years in manufacturing. We always want several pairs of "fresh eyes" on the teams. These are people that know nothing about the process.
Title: Re: Stupid Questions :o
Post by: ChrisReynolds on March 19, 2013, 06:25:31 PM
Wanderer,

I tend to agree with Neven, the new season in terms of area/extent starts from the day of maximum area/extent, typically in March. However the volume decline season starts later in April, because thickening within the Arctic ocean continues even as the peripheral oceans area/extent is falling.

It makes sense to consider that the melt season starts from when the net trend starts to be loss. However I would have some sympathy with a combined start date of the Spring equinox, as it is the solar input that drives the seasonal cycle.

In the end the question of which is the better approach is answered by considering what you intend to do with the baseline you've set: Be it a moveable date of maximum, or a fixed date related to solar influence.
Title: Re: Stupid Questions :o
Post by: Anonymouse on March 21, 2013, 05:54:26 AM
So this is the question I have been mulling over...  years ago (I cannot find my source for the life of me) I read about a "lag" in CO2 readings.  Like, a lag of about 50 years.  So is it true (I hope not) that the effects we are seeing now are the result of carbon released years and years ago? If true, what does this say about the effects yet to be seen from steadily increasing releases since the 1950's?  If we are rapidly approaching 400ppm this year, what does that say about upcoming years?  I am well aware that CO2 is extremely long-lived and remains in the atmosphere for decades and centuries, if not longer.  So I guess I am trying to wrap my head around what and when today's changes (like the current drama in the Arctic ice) might be attributed to - I am pretty sure it was not my trip to the local grocery store yesterday - and I fear grocery stores are going to become relics.
Title: Re: Stupid Questions :o
Post by: CraigsIsland on March 21, 2013, 06:08:18 AM
Good news is- we still have time to slow that ppm down. Some people believe 450ppm is the point of no return. Bad news is that nobody is listening. Or rather- the people required to listen are too in debt with coal/oil/energy industry to dedicate energy policy around leaving carbon in the ground. In reality there is no "magic" ppm number, it's still way above any normal historical ppm without AGW. Can we stop it before it becomes a runaway situation?

I'm not sure "when" the public will awaken but the perception of a problem and the scale of resources needed to bring the ppm down is a challenge.
Title: Re: Stupid Questions :o
Post by: Anonymouse on March 21, 2013, 06:35:27 AM
Dear CraigsIsland (#6),
Well, of course we can slow the ppm down, but how far into the future will it have an effect? My personal headcase is trying to figure out what the ppm will be in 50 years, even if we shut everything down tomorrow, due to the "lag" which I am not sure is a real thing or just something I heard somewhere.  Thanks for the reply, I totally agree with you, though!  :)
Title: Re: Stupid Questions :o
Post by: CraigsIsland on March 21, 2013, 07:05:41 AM
From James Hansen - nice collection of figures has an embedded chart of PPM as of Feb. 2013:

http://www.columbia.edu/~mhs119/UpdatedFigures/ (http://www.columbia.edu/~mhs119/UpdatedFigures/)

it's seems to be a steady climb up. 50 years from now? definitely north of 450. When will we feel it? probably at a quicker rater than what we pumping into the atmosphere somewhere. It's a good question though. To put it another way - during what time frame did our climate change because of "x" amount of carbon put some time ago to create today's conditions? 2005? 2007?

If that "450" number is correct, when will we feel those specific effects? We'd feel it a lot quicker than 400. I think we'll hit 450 easily within 10 years and effects will hit 3-5 years after that.
Title: Re: Stupid Questions :o
Post by: Anonymouse on March 21, 2013, 07:46:51 AM
Thanks again CraigsIsland!
Your "to put it another way" question perfectly articulates the question I was groping at.  As a noob, it is much appreciated.   Thanks also for the Hansen figures.  I haven't looked at them yet, but the Keeling curve has been more or less steadily upward since I was introduced to it years-n-years ago (that is what got me seriously worried in the first place - the implications are just astounding to me.) 
I guess I am wondering if we are currently feeling the effects of 350 (or whatever) in lagged time.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on March 21, 2013, 08:55:32 AM
My stupid question relates to the moon's orbit. As the max declination of the moon from the equator plane is 28,7deg, wouldn't this create a circular wave of tide on an open ocean above 38,7 degrees north?  On earth the only example is the Arctic Ocean.(EDIT: well Antarctic cirumpolar currents might also apply) With the tides rushing to shores, and moving a bit forward with the moon as it recedes, wouldn't this create a tidally driven coastal current on such an ocean? I bet this has been discussed somewhere in the blog already, but not bothering to seek the info now. is this an east- or westward current? Does it have much to say in the cracking spring ice?

There could be some use for a 'basics'-thread  for those entering this forum area? sort of RTFM of physics related to ice and arctic. for me, it's been somewhat tedious f.e. to find out many of the locations mentioned  in the posts, so a reference map would be nice.
Title: Re: Stupid Questions :o
Post by: ivica on March 21, 2013, 10:00:45 AM
...it's been somewhat tedious f.e. to find out many of the locations mentioned  in the posts, so a reference map would be nice.

Perhaps this helps a bit, Arctic Map:
http://www.arctic.io/zoom/XpKT/0.506339;0.532550;1.012468/Arctic-Map (http://www.arctic.io/zoom/XpKT/0.506339;0.532550;1.012468/Arctic-Map)
Title: Re: Stupid Questions :o
Post by: johnm33 on March 21, 2013, 01:09:06 PM
The Atlantic water comes in and as it evaporates/freezes the remainder becomes more saline and sinks into the arctic basins, then what?
http://polardiscovery.whoi.edu/arctic/circulation.html (http://polardiscovery.whoi.edu/arctic/circulation.html)
 Surely they [basins] must be overflowing somewhere.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on March 21, 2013, 01:26:36 PM
PMT111500.....

As an uninformed lurker myself, this is an interesting question. The cracks (seeming to originate near the coasts) have been occurring over the past month, since Feb10. It would seem to be not that difficult to determine if a correlation exists between the moon's location and tidal impact with the crack formation. I think only one of resident experts could look at this. It is certainly beyond me.
Title: Re: Stupid Questions :o
Post by: PhilGChapman on March 21, 2013, 01:31:36 PM
Great map ivica, thanks :)
Title: Re: Stupid Questions :o
Post by: Shared Humanity on March 21, 2013, 01:37:45 PM
johnm33.....

Don't know if the basin is filling (I would think not) but is that needed for the Atlantic water that sinks into the Arctic Basin to impact melt? Could the ridges, especially the Lomonosov Ridge cause this warm salty water to upswell and cause melt under the icecap? I have been unintelligently luking here for about a year. There is a thin ice feature in the CAB (I think it is called the Laptev bite) which seems to parallel this ridge. Could this ridge be forcing the warm salty water up and be the engine behind the Laptev bite?

Again a question for the better informed.

Neven, would it be possible for some of the resident experts to visit here and scan our stupid questions? All of these "fresh eyes" may stumble onto something (besides our tongues) that is worth a more thorough discussion on an expert thread.
Title: Re: Stupid Questions :o
Post by: Vergent on March 21, 2013, 02:02:01 PM
...it's been somewhat tedious f.e. to find out many of the locations mentioned  in the posts, so a reference map would be nice.

Perhaps this helps a bit, Arctic Map:
http://www.arctic.io/zoom/XpKT/0.506339;0.532550;1.012468/Arctic-Map (http://www.arctic.io/zoom/XpKT/0.506339;0.532550;1.012468/Arctic-Map)

Thanks for the map, I always wondered where Avannaarsua, Groenlandia was.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on March 21, 2013, 03:08:35 PM
thanks ivica, that's about the best map of Arctic I've seen in the net. then if someone would set the names of the major Greenland glaciers on it, it would make an excellent map.

On glacier names there's  this site http://www.satelliteviews.net/cgi-bin/w.cgi?c=gl&DG=GLCR (http://www.satelliteviews.net/cgi-bin/w.cgi?c=gl&DG=GLCR)
this site  but it includes every small glacier too, being too detailed outside scientists i guess.

I've been checking glacier names from wikipedia list http://en.wikipedia.org/wiki (http://en.wikipedia.org/wiki) /List_of_glaciers_in_Greenland  but it's typically for wikipedia arranged to an alphabetical order. a map might help to remember  if  Zachariae is north of 79deg-glacier or not, for examnple.
Title: Re: Stupid Questions :o
Post by: Donna on March 21, 2013, 03:45:54 PM
My stupid question - what is the "goats head"?  In another thread someone asked if the goats head was going to go into the Fram Straight this year. 

My guess is that it's a persistent multi-year ice formation - is that correct? 

Second stupid question, what are the ramifications of the goats head going into the Fram Straight? 

Title: Re: Stupid Questions :o
Post by: ivica on March 21, 2013, 03:48:16 PM
If it is of any help,
attached is large Map (2800 x 4858) of Greenland, 2.3 MB.
Unfortunately I do not recall source.
Title: Re: Stupid Questions :o
Post by: ritter on March 21, 2013, 04:19:02 PM
My stupid question - what is the "goats head"?  In another thread someone asked if the goats head was going to go into the Fram Straight this year. 

My guess is that it's a persistent multi-year ice formation - is that correct? 

Second stupid question, what are the ramifications of the goats head going into the Fram Straight?

I'm another novice but can confirm your guess is correct. Generally, if ice exits via the Fram, it is transported out of the Arctic and melts away.
Title: Re: Stupid Questions :o
Post by: TerryM on March 21, 2013, 05:14:24 PM




Arctic.io has a number of Arctic maps that many may find helpful and the NSIDC Atlas of the Cryosphere with it's overlays is a great resource.
http://nsidc.org/cgi-bin/atlas_north? (http://nsidc.org/cgi-bin/atlas_north?)


The USGS Satellite Images Atlas of Greenland has maps and images.
http://pubs.usgs.gov/pp/p1386c/p1386c.pdf (http://pubs.usgs.gov/pp/p1386c/p1386c.pdf)



For those interested in the GIS
http://www.skepticalscience.com/Variations_in_Greenland_Glaciers.html#47339 (http://www.skepticalscience.com/Variations_in_Greenland_Glaciers.html#47339)
is a must read.


Terry



Title: Re: Stupid Questions :o
Post by: Shared Humanity on March 22, 2013, 12:24:12 AM
Donna.....Goat's head is a floe of MYI that has been hanging out in the CAB for several years??? Someone posted an animation of the ice moving and it looked like this MYI was moving quickly towards Fram.
Title: Re: Stupid Questions :o
Post by: wanderer on March 22, 2013, 09:41:41 AM
I'll repost an interesting, yet unheard question Jim Williams asked at the Blog:

http://neven1.typepad.com/blog/2013/03/max-reached-.html?cid=6a0133f03a1e37970b017d422bcc85970c#comment-6a0133f03a1e37970b017d422bcc85970c (http://neven1.typepad.com/blog/2013/03/max-reached-.html?cid=6a0133f03a1e37970b017d422bcc85970c#comment-6a0133f03a1e37970b017d422bcc85970c)

"Looking at 1) Current Baffin/Newfoundland Sea Ice Area, 2) Sea Surface Temperature anomaly in the North-West Atlantic, 3) the Surface Air temperature Anomaly West of (and over) Greenland, and 4) the AO, I'd like to re-ask a question I asked last fall. What happens if the Gulf Stream decides to flow to the West of Greenland?"

Title: Re: Stupid Questions :o
Post by: Pmt111500 on March 22, 2013, 12:20:46 PM
"What happens if the Gulf Stream decides to flow to the West of Greenland?"

I'm not too sure it can do that since the East Greenland current is likely to stay the coldest current out of the arctic no matter what running in the the deepest channel = Fram Strait.
http://nordpil.com/static/images/arctic_topographic_map_full.jpg (http://nordpil.com/static/images/arctic_topographic_map_full.jpg) (the best map i've found)

(edited to clarify)
but maybe it could be split in two (partly connecting to west Greenland current) somewhere south of Greenland southern cape. Only if there was a permanent high pressure area between Europe and Greenland it might completely change course. This has happened for a short while during 2009-2010 winter.
http://www.dailykos.com/story/2010/01/06/822520/-Freak-Current-Takes-Gulf-Stream-to-Greenland (http://www.dailykos.com/story/2010/01/06/822520/-Freak-Current-Takes-Gulf-Stream-to-Greenland)
so I'm not ruling out the complete diversion of the gulf stream totally.
Title: Re: Stupid Questions :o
Post by: Jim Williams on March 22, 2013, 02:50:19 PM
"What happens if the Gulf Stream decides to flow to the West of Greenland?"

...
but maybe it could be split in two (partly connecting to west Greenland current) somewhere south of Greenland southern cape. Only if there was a permanent high pressure area between Europe and Greenland it might completely change course. This has happened for a short while during 2009-2010 winter.
http://www.dailykos.com/story/2010/01/06/822520/-Freak-Current-Takes-Gulf-Stream-to-Greenland (http://www.dailykos.com/story/2010/01/06/822520/-Freak-Current-Takes-Gulf-Stream-to-Greenland)
so I'm not ruling out the complete diversion of the gulf stream totally.

Certainly, there is the North Atlantic drift.  Let's just take the North Wall, and maybe not even all of it.  Seems to me the High is over Greenland, not east of it -- but what I'm looking at over the last few years that matters is the general northward shift in the Western Boundary Currents.

What happens if a significant fraction of tropical Atlantic water flows to the west of Greenland rather than East of it?  Arguing over whether such a change is a cause or an effect is separate, as is arguing whether it is actually happening or not.

I am looking at phenomena that leads me to ask the question -- but they are not what I'd consider conclusive.  One could ask the slightly different question of what it would look like if the current were making this transition......
Title: Re: Stupid Questions :o
Post by: PhilGChapman on March 29, 2013, 05:45:54 PM
Hi Johnm33,
Your intuition serves you well! What you are describing there is deep water formation, which takes water on a thermohaline odyssey that ultimately leads to the north pacific some hundreds of years later.
It's not just surface waters that leave the Arctic through the Fram Strait, but also intermediate and deep water that flows on southwards through the Denmark straight. Other significant deep waters that form and flow south in the region are Labrador sea water and Iceland-Scotland overflow water. Their path is largely driven by bathymetry. See here (http://ars.els-cdn.com/content/image/1-s2.0-S0079661107000833-gr1.jpg) for an indication. (And partly why the North-Atlantic drift isn't about to start flowing west of Greenland)
Title: Re: Stupid Questions :o
Post by: Vergent on March 29, 2013, 11:13:11 PM
Quote
What happens if the Gulf Stream decides to flow to the West of Greenland?

Basically, it can't. The water at low latitudes has a significant rotational velocity(at the equator 1000mph) This translates into momentum to the east as it travels north where the rotational velocity is lower(0.0mph at the pole). This momentum caries it south of Greenland and into the Barents. There is no way it makes that left turn, without an incredible force being applied to it continuously.Some does flow into the Fram, That is because sea level is low there, due to the strong deep outflow(Venture's effect).

The warm water that blog is showing west of Greenland came from Labrador continental shelf (where they had a +5C anomaly this year).

Quote
The Gulf Stream is typically 100 kilometres (62 mi) wide and 800 metres (2,600 ft) to 1,200 metres (3,900 ft) deep. The current velocity is fastest near the surface, with the maximum speed typically about 2.5 metres per second (5.6 mph).
Title: Re: Stupid Questions :o
Post by: Jim Williams on March 30, 2013, 01:10:32 PM
Quote
What happens if the Gulf Stream decides to flow to the West of Greenland?

Basically, it can't. The water at low latitudes has a significant rotational velocity(at the equator 1000mph) This translates into momentum to the east as it travels north where the rotational velocity is lower(0.0mph at the pole). This momentum caries it south of Greenland and into the Barents. There is no way it makes that left turn, without an incredible force being applied to it continuously.Some does flow into the Fram, That is because sea level is low there, due to the strong deep outflow(Venture's effect).

The warm water that blog is showing west of Greenland came from Labrador continental shelf (where they had a +5C anomaly this year).

Quote
The Gulf Stream is typically 100 kilometres (62 mi) wide and 800 metres (2,600 ft) to 1,200 metres (3,900 ft) deep. The current velocity is fastest near the surface, with the maximum speed typically about 2.5 metres per second (5.6 mph).




Are you confusing the Gulf Stream and the North Atlantic Drift?  It is quite common to conflate the two currents, but there is a big difference between them.  Last I read, they still didn't know why the Gulf Stream detaches from North America at North Carolina.

I might also add that the Gulf Stream, at least in part, did in fact flow to the west of Greenland briefly in the Winter of 2010.

Please see: http://en.wikipedia.org/wiki/Boundary_current (http://en.wikipedia.org/wiki/Boundary_current) (espcially Western Boundary Current, and Western Intensification)


Quote
Western boundary currents

The world's largest ocean gyres Western boundary currents are warm, deep, narrow, and fast flowing currents that form on the west side of ocean basins due to western intensification. They carry warm water from the tropics poleward. Examples include the Gulf Stream, the Agulhas Current, and the Kuroshio.

Western intensification

Western intensification is the intensification of the western arm of an oceanic current, particularly a large gyre in an ocean basin. The trade winds blow westward in the tropics, and the westerlies blow eastward at mid-latitudes. This wind pattern applies a stress to the subtropical ocean surface with negative curl in the northern hemisphere and a positive curl in the southern hemisphere. The resulting Sverdrup transport is equatorward in both cases. Because of conservation of mass and potential vorticity conservation, that transport is balanced by a narrow, intense poleward current, which flows along the western boundary of the ocean basin, allowing the vorticity introduced by coastal friction to balance the vorticity input of the wind. Western intensification also occurs in the polar gyres, where the sign of the wind stress curl and the direction of the resulting currents are reversed. It is because of western intensification that the currents on the western boundary of a basin (such as the Gulf Stream, a current on the western side of the Atlantic Ocean) are stronger than those on the eastern boundary (such as the California Current, on the eastern side of the Pacific Ocean). Western intensification was first explained by the American oceanographer Henry Stommel.

Title: Re: Stupid Questions :o
Post by: Vergent on March 30, 2013, 06:33:15 PM
Are you confusing the Gulf Stream and the North Atlantic Drift?  It is quite common to conflate the two currents, but there is a big difference between them.
No, I am not confusing them but you are. You see the "North Atlantic Drift" is the northern part of the Gulf Stream. To talk about the Gulf Stream re. Greenland is to include the North Atlantic drift as subset of the Gulf Stream. Are you confusing yourself with your right leg?

Quote
  Last I read, they still didn't know why the Gulf Stream detaches from North America at North Carolina.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fupload.wikimedia.org%2Fwikipedia%2Fcommons%2Fthumb%2F1%2F19%2FGolfstrom.jpg%2F300px-Golfstrom.jpg&hash=57709c58ba2b092f3789b330810115d6)
The Gulf Stream detaches from North America at North Carolina simply because it does not change direction for no good reason(conservation of momentum). This has been understood since 1687.
Quote
I might also add that the Gulf Stream, at least in part, did in fact flow to the west of Greenland briefly in the Winter of 2010.

No, that would have been the Irminger current. First described in 1854.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fmedia-2.web.britannica.com%2Feb-media%2F24%2F149024-004-B14614AA.jpg&hash=f75baa1e6af2632493484e17905f079c)
Title: Re: Stupid Questions :o
Post by: ChrisReynolds on March 30, 2013, 08:49:16 PM
Nice graphic Vergent,

Carl Wunsch is correct, reduction of overturning circulation will not impact ocean heat transport to Europe. Nothing short of the globe stopping turning would do that.
Title: Re: Stupid Questions :o
Post by: Chuck Yokota on March 30, 2013, 11:29:26 PM
Here is another stupid question:  Does all the cold air moving into the mid-latitudes from the Arctic this year mean that warmer air has moved in to replace it in the Arctic, increasing temperatures and melting there?
Title: Re: Stupid Questions :o
Post by: gfwellman on March 31, 2013, 04:45:21 AM
Not a stupid question.  The answer is generally yes.  We get those arctic blasts in the mid-latitudes when the arctic "loses containment" often due to meanders in the polar jet stream.  This typically does mean that mid-latitude air is drawn north behind the arctic outbreak.
Title: Re: Stupid Questions :o
Post by: Jim Williams on March 31, 2013, 02:03:36 PM
Quote
I might also add that the Gulf Stream, at least in part, did in fact flow to the west of Greenland briefly in the Winter of 2010.

No, that would have been the Irminger current. First described in 1854.


See:  http://www.dailykos.com/story/2010/01/06/822520/-Freak-Current-Takes-Gulf-Stream-to-Greenland (http://www.dailykos.com/story/2010/01/06/822520/-Freak-Current-Takes-Gulf-Stream-to-Greenland)

Unfortunately, those plots are sold to shipping companies and it is hard to get current maps of the Gulf Stream.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on March 31, 2013, 03:50:40 PM
A simple request from a simple person.....

Given the title of this post and recognizing I am a source of stupid questions, I think this topic is intended to allow those of us who know very little (I am certainly one of them.) to ask questions that may not make sense. I hope it will encourage new visitors to begin to develop some understanding. As such, it would help if responses to people who post here are not dismissive and derogatory. The effect will to discourage new people from visiting and asking questions.
Title: Re: Stupid Questions :o
Post by: ggelsrinc on April 02, 2013, 05:01:04 AM
My stupid question is when was the last time the arctic was ice free?

I've posted claims from articles and refuted someone claiming the arctic was ice free during the Holocene Climatic Optimum by posting a study of sediment cores proving the area north of Greenland wasn't ice free then, but I've never seen a real scientific study showing the past conditions of sea ice in the arctic.
Title: Re: Stupid Questions :o
Post by: Neven on April 02, 2013, 06:19:25 AM
Here's a good paper for that not stupid question (wrong thread!): Polyak et al. 2010, History of sea ice in the Arctic (http://bprc.osu.edu/geo/publications/polyak_etal_seaice_QSR_10.pdf) (PDF)

If my memory serves me well, I believe that it must've been in the previous interglacial, more than 100K-120K years ago, that the Arctic Ocean could've been ice-free, if it wasn't somewhere during the Holocene Climatic Optimum.
Title: Re: Stupid Questions :o
Post by: gfwellman on April 02, 2013, 06:43:49 AM
Yeah, there's some evidence of wave action in northern Greenland 8000 years ago that would imply significant periods where that coast was ice free, but it's far from a sure thing.  The previous interglacial is known to have been warm enough.
Title: Re: Stupid Questions :o
Post by: JMP on April 02, 2013, 11:26:08 AM
I have a lot of stupid stupid questions.  So here goes! :D

 May be somewhat or probably related to the discussion on currents?

What's the result of the saline-rich dense water that's being produced by more first year ice and more melting?   Is there basically more energy in the system?  Does that mean an increase in circulation?  Is this going to send more ice out of the Fram?  Is more relatively warm water going to be drawn northward into the arctic ocean or is the increase in circulation contained within the Arctic basins etc?  Is the dense saline water relatively warm and causing a thermal-inversion layer (warm under cold)?  And finally, if yes to critical aspects above is this another positive feedback?   

-john
Title: Re: Stupid Questions :o
Post by: Anne on April 02, 2013, 11:27:49 AM
My stupid question relates to freshwater run-off from Greenland. The behaviour of low density meltwater is being put forward as a possible explanation for increasing winter ice in Antarctica. 
http://www.bbc.co.uk/news/science-environment-21991487 (http://www.bbc.co.uk/news/science-environment-21991487)

Might we see a similar effect in the Arctic, even to the south of Greenland, where meltwater is coming off land rather than from underneath an ice shelf?
Title: Re: Stupid Questions :o
Post by: Vergent on April 03, 2013, 07:58:19 PM
Anne,

This effect may help thicken the ice to the north of Greenland in the past. But this ice has been mobilized by the cracking and probably will end up in the Greenland Sea, where it will get transported south and melt. Baffin Bay is seasonal ice so there can be no net accumulation.

The main melting is in Aug-Sept, The freeze up in Baffin is in November, so the Labradore Current will have taken the fresh water away from the West side.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Farctic.atmos.uiuc.edu%2Fcryosphere%2FIMAGES%2Frecent365.anom.region.4.jpg&hash=39033654d6c2d970e5a31c2e802112aa)

The negative anomaly suggests that this mechanism is not playing a major role.
Title: Re: Stupid Questions :o
Post by: Anne on April 03, 2013, 09:59:06 PM
Thank you, Vergent.
Title: Re: Stupid Questions :o
Post by: Sigmetnow on April 05, 2013, 02:58:08 AM
Here’s one I haven’t seen mentioned:  On a sunny, sub-freezing day, how much sea ice (or ice-sheet ice) can be lost through sublimation (ice changing directly to water vapor)?
Title: Re: Stupid Questions :o
Post by: TerryM on April 05, 2013, 04:20:38 AM
Sigmetnow


Very possibly a stupid answer.


It will depend on wind speed, atmospheric dry bulb/wet bulb ratio and actual temperature, probably in that order. It takes a lot of energy to sublimate ice - add both phase changes together 334 J/g + 2260 J/g = 2594 J/g - so a strong dry warm breeze would help.


You could melt about 7.75 kilos of ice or sublimate 1 kilo with about the same amount of energy.


Terry
Title: Re: Stupid Questions :o
Post by: John Batteen on April 05, 2013, 08:14:48 AM
Never thought of that one Sigmetnow, good question.  I do notice that a surprising amount of ice sublimes from the roads during the cold sunny days of winter, even when it's 0F.  With the roads it's a little different though, because the ice is on top of a black asphalt road that readily warms in the sun.
Title: Re: Stupid Questions :o
Post by: Sigmetnow on April 05, 2013, 03:16:58 PM
Right.  I kept looking at the Sea Surface Temps and the Air Surface Temps and thinking, “As long as those are cold, the ice is pretty safe.”  But with sublimation, I guess it’s only about 1 / 7.75 -- or 87% --  safe.   ;)

And don’t forget wind, ocean currents -- and darkening influences such as soot.... 
Here’s an article on how a dust storm from Oregon and Nevada vastly accelerated snow melt on a mountain in Idaho:

http://thinkprogress.org/climate/2013/04/01/1804161/idaho-dust-storm-speeds-up-snowmelt-nobody-on-our-staff-has-ever-witnessed-anything-similar/?mobile=wp (http://thinkprogress.org/climate/2013/04/01/1804161/idaho-dust-storm-speeds-up-snowmelt-nobody-on-our-staff-has-ever-witnessed-anything-similar/?mobile=wp)


Isn’t there a trend towards more high-pressure areas (“anti-cyclones”) over the arctic ice these days?  That would mean more sunshine, as well.
Title: Re: Stupid Questions :o
Post by: Vergent on April 05, 2013, 05:19:12 PM
Isn’t there a trend towards more high-pressure areas (“anti-cyclones”) over the arctic ice these days?  That would mean more sunshine, as well.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.cpc.ncep.noaa.gov%2Fproducts%2Fprecip%2FCWlink%2Fdaily_ao_index%2Fao.obs.gif&hash=eb83d0454cdc9e996658f850c992154d)

The measure of this is called the AO(arctic oscillation). A strong negative AO=arctic anti-cyclone.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index.html (http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index.html)
Title: Re: Stupid Questions :o
Post by: Jim Williams on April 05, 2013, 06:04:07 PM
Is the AO going to go even more negative than March, or is Spring going to set in first?
Title: Re: Stupid Questions :o
Post by: crandles on April 05, 2013, 06:15:00 PM
Is the AO going to go even more negative than March, or is Spring going to set in first?

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.cpc.ncep.noaa.gov%2Fproducts%2Fprecip%2FCWlink%2Fdaily_ao_index%2Fao.sprd2.gif&hash=893610134f5ea33e74ae897b859fcc59)
Title: Re: Stupid Questions :o
Post by: ivica on April 09, 2013, 06:40:48 PM
thanks ivica, that's about the best map of Arctic I've seen in the net. then if someone would set the names of the major Greenland glaciers on it, it would make an excellent map.

On glacier names there's  this site http://www.satelliteviews.net/cgi-bin/w.cgi?c=gl&DG=GLCR (http://www.satelliteviews.net/cgi-bin/w.cgi?c=gl&DG=GLCR)
this site  but it includes every small glacier too, being too detailed outside scientists i guess.

I've been checking glacier names from wikipedia list http://en.wikipedia.org/wiki (http://en.wikipedia.org/wiki) /List_of_glaciers_in_Greenland  but it's typically for wikipedia arranged to an alphabetical order. a map might help to remember  if  Zachariae is north of 79deg-glacier or not, for examnple.
Greenland marine-terminating glacier area changes: 2000–2010 (http://bprc.osu.edu/~jbox/pubs/Box_and_Decker_2011_Annals.pdf) has glaciers location map on the page 92.
Title: Re: Stupid Questions :o
Post by: wanderer on June 25, 2013, 01:57:13 PM
Are those melt lakes?

Title: Re: Stupid Questions :o
Post by: Peter Ellis on June 25, 2013, 03:42:18 PM
Yes
Title: Re: Stupid Questions :o
Post by: LurkyMcLurkerson on June 26, 2013, 10:19:10 PM
I don't have a stupid question at the moment, entirely because a couple of my stupid questions are posited in much smarter ways and answered above.

So I'll just add: great thread for all of us with a lot of catching up to do, and many thanks to those more knowledgeable posters skimming and answering as they can.
Title: Re: Stupid Questions :o
Post by: helorime on July 01, 2013, 08:14:55 PM
Hi,

Newbie here.  Been watching the arctic for a few years, lurking here some weeks, and a weather junkie on many fronts. I am a geneticist, not a meteorologist or physicist, so I am pretty ignorant currently. My stupid questions:  1. Where are people finding close to real-time satellite images as opposed to the once a day updates to build those cool composite maps, without the big swaths of cloud cover hiding stuff, and 2.  Is there any previous record of the massive amount of random ice rubble that we are currently seeing in the arctic basin? If not, why isn't it all over the place in general news?
Title: Re: Stupid Questions :o
Post by: Neven on July 01, 2013, 08:33:37 PM
Welcome, helorime, and very good stupid questions.  ;D

1) Have you checked out the Arctic Sea Ice Graphs page? Where did you see someone post such an image? You can fiddle with images from IJIS or the 3-6-7 Bands (http://lance-modis.eosdis.nasa.gov/imagery/subsets/?mosaic=Arctic.2013182.terra.367.4km) on the Terra satellite. Other than that, there are folks here - like Wipneus - who retrieve microwave data themselves and build their own sea ice concentration maps.

2) The random ice rubble is to my knowledge unprecedented in this phase of the melting season. 2010 was similar, but only at the end of the melting season. It isn't in the general news because it's not enough as of yet (and the mainstream media is what it is). It has to be worse, preferably combined with low extent/area numbers. Give it time.
Title: Re: Stupid Questions :o
Post by: helorime on July 01, 2013, 08:51:28 PM
Thank you  :)  I knew about the graphs page but not the satellite sites.   Interesting color coding.  About the rubble, I guess if there is no precedent it is impossible to predict the effects it will have.  It seemed to me from the first time I spotted it that there would be catastrophic melting, but that has not happened (yet).
Title: Re: Stupid Questions :o
Post by: Wipneus on July 01, 2013, 08:57:34 PM
, there are folks here - like Wipneus - who retrieve microwave data themselves and build their own sea ice concentration maps.


Certainly not microwave data. The data from uni hamburg is already gridded concentration data, from which I build maps, calculate SIA, SIE and what else is interesting.
Title: Re: Stupid Questions :o
Post by: Neven on July 01, 2013, 11:11:14 PM
Certainly not microwave data. The data from uni hamburg is already gridded concentration data, from which I build maps, calculate SIA, SIE and what else is interesting.

I apologize for ascribing super powers to you.  8)

Quote
It seemed to me from the first time I spotted it that there would be catastrophic melting, but that has not happened (yet).

This is often the interesting thing about the melting season - which is also why this melting season reminds me so much of 2010 - in that there's always a lot of melting potential, but at the same time the end of the melting season approaches which could cut that potential short.

In this case the end of the melting season is still quite some time into the future, and so the unprecedentedness will become more visible/obvious, but at the same time the ice pack could become so dispersed that the end of the melting season can cut all of that potential short.

Right now I feel anything is possible, even a new record.
Title: Found the Goat's Head?
Post by: gideonlow on July 02, 2013, 05:44:38 AM
I think I found it yesterday hiding in the "Terra/MODIS Corrected Reflectance (3-6-7)" layer on NASA Worldview.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fmap2.vis.earthdata.nasa.gov%2Fimagegen%2Findex.php%3FTIME%3D2013181%26amp%3Bextent%3D-9782.2862910004%2C-6706.5418600002%2C197833.713709%2C103117.45814%26amp%3Bepsg%3D3413%26amp%3Blayers%3DMODIS_Terra_CorrectedReflectance_Bands367%2Carctic_graticule_3413%2Carctic_coastlines_3413%26amp%3Bformat%3Dimage%2Fjpeg%26amp%3Bwidth%3D811%26amp%3Bheight%3D429&hash=85b3af899d894d93e0de89c501171c37)

If you look at the center-right area, basically following the 60 Degrees East Longitude, the putative "Goat's Head" is sitting on its side, with the longer "horn" sticking out below the line and to the right, and the smaller "horn" above that (also to the right).  The "head" extends along/above the longitude line down to the left.  Both horns are starting to disintegrate, but the one to the bottom/right (the "left" side of the head looking at you) is holding together better.  I've attached a cut-out of the shape, but am not sure how to imbed my attachment in the this post  :-\

So, my stupid question is: Have I actually found the famous "Goat's Head", or is this just a coincidentally similar shape in the same general area where the real Goat's Head was last spotted?  Interestingly, the shape is only visible--at least to my untrained eye--with the Terra MODIS 3-6-7 Corrected Reflectance layer.

I asked the question on Neven's blog, but I think this is probably the most appropriate place.

Cheers,

Gideon

Update: Ah, I just saw when I posted, the attachements did indeed show-up in the post (even though they didn't show-up in the preview).
Title: Re: Stupid Questions :o
Post by: Peter Ellis on July 02, 2013, 09:20:00 AM
I can't make out that shape at all without your cropping.  It's also 90 degrees rotated from the last time the goat's head was visible on Ascat (first few days of June), and less than a third of the size.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on July 02, 2013, 04:10:08 PM
I can't make out that shape at all without your cropping.  It's also 90 degrees rotated from the last time the goat's head was visible on Ascat (first few days of June), and less than a third of the size.

I think the goats head bought the farm during PAC 2013.
Title: Re: Stupid Questions :o
Post by: Vergent on July 02, 2013, 05:53:41 PM
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.aari.ru%2Fresources%2Fd0015%2Farctic%2Fgif.en%2F2013%2F20130528.GIF&hash=7719fec4cac974647994e1b247016372)

The "goat's head" May 28. Buoy drift maps show insufficient movement for the goats head to have moved that far.

http://psc.apl.washington.edu/northpole/pngs/DriftMap.png (http://psc.apl.washington.edu/northpole/pngs/DriftMap.png)

So the answer is; "no, that is not the goat's head."

Vergent
Title: Re: Stupid Questions :o
Post by: gideonlow on July 03, 2013, 07:45:06 PM
Now that I see the proper scale, I agree it is definitely too small to be the Goat's Head (and even though the resemblance was uncanny, the new shape I found is also incorrect in that it's a mirror image).  The last time I saw the GH in one of (I think) A-Team's animations, however, it was directly over the pole & perhaps losing a horn. With all the thrashing being doled-out by the 2013-PAC, plus with the typical drift from the pole towards the Fram seemingly interrupted recently, the positioning seemed to be reasonable. 

Thanks for taking a look.

@SH -- Although the Goat may have succeeded in, ahem, gaining its independence from profiteering ownership, at least it hasn't "Bought the Fram" ;-)

Cheers,

Gideon
Title: Re: Stupid Questions :o
Post by: seawolf on July 04, 2013, 06:33:35 PM
Why does arctic ice spread out under the effect of a cyclone? The cyclonic winds close to the surface actually point slightly towards the center of the cyclone. Isn't the ice driven by the surface winds? Then why doesn't it follow the converging winds?

 
Title: Re: Stupid Questions :o
Post by: TerryM on July 04, 2013, 08:31:09 PM
Seawolf


Google for "Ekman Pumping"


Terry
Title: Re: Stupid Questions :o
Post by: Anne on July 04, 2013, 10:03:46 PM
More stupid questions: with less ice cover on the Arctic ocean, what will be the effects on the movement of seawater? What about the tides? Clearly we can expect to see seasonal flooding and erosion along Arctic shores normally protected by ice. But it's a huge body of water that will become more dynamic, at least in wave amplitude. It will be more affected by wind. What will be the effects of this? Won't there be massive changes in current? Can we expect a pan-Arctic gyre?
Title: Re: Stupid Questions :o
Post by: John_The_Elder on July 05, 2013, 03:43:40 AM
One major implication of an "ice free" artic is the formation of the "North Atlantic Deep Water" (NADW). This is one of the main drivers for Thermohaline Circulation.
It is possible that a disruption of the NADW could lead to extreme climate change, with less CO2 sinking to the ocean depths. Not very nice for the creatures of the earth.
Title: Re: Stupid Questions :o
Post by: Richard Rathbone on July 06, 2013, 12:14:24 AM
Why does arctic ice spread out under the effect of a cyclone? The cyclonic winds close to the surface actually point slightly towards the center of the cyclone. Isn't the ice driven by the surface winds? Then why doesn't it follow the converging winds?

 

Its the same reason the wind goes round in a cyclone. The driving force for the wind is along the pressure gradient directly into the centre of the cyclone. The earth's spin carries it off at an angle (almost 90 degrees) instead. The ice is driven by friction from the wind around the cyclone, but the earths spin carries it off at an angle instead.

If the ice was not restrained by its own strength, and by friction with the water underneath, it would go at almost 90 degrees to the wind and move directly outwards, just like the wind is at almost 90 degrees to the pressure. In practice these effects combine so that the ice moves at 20-30 degrees to the wind rather than 90 degrees to it.

The water shows this spiralling of movement too. Just as the wind moves at an angle to the pressure gradient, and then the ice moves at an angle to the wind, the water directly under the ice moves at an angle to the ice, the next layer of water down moves at an angle to the water above it and so on.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on July 08, 2013, 08:30:44 AM
Did someone calculate the correlation between AO and CAPIE at some point in time? Is monthly AO index a record frequent enough to find the correlation that should be there? Is there difference between winter and summer numbers in this correlation? What's the delay on the relationship, a week/two weeks/a month? Where to find weekly values of AO? Aww, sorry for the last one, once again didn't look for hard enough...
ftp://ftp.cpc.ncep.noaa.gov/cwlinks/norm.daily.ao.index.b500101.current.ascii
Title: Re: Stupid Questions :o
Post by: Vergent on July 09, 2013, 04:00:14 AM
Why does arctic ice spread out under the effect of a cyclone? The cyclonic winds close to the surface actually point slightly towards the center of the cyclone. Isn't the ice driven by the surface winds? Then why doesn't it follow the converging winds?

 

The simplest answer. Conservation of angular momentum. The air transfers its angular momentum to the ice. The net push is tangential to the center of the storm.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.ijis.iarc.uaf.edu%2Fseaice%2Fdata%2FWIND%2F201208%2FJMAWIND2012080812_polar.png&hash=3e6a8474ab4e6d8230fa505391b3e002)

Here is the wind field of GAC-12.

Vergent
Title: Re: Stupid Questions :o
Post by: TerryM on July 29, 2013, 07:26:15 PM
I understand that the maximum density of fresh water occurs at 3.98C. Would seawater also reach it's maximum density at this temperature assuming salinity remained constant?


Terry
Title: Re: Stupid Questions :o
Post by: mhampton on July 29, 2013, 08:00:47 PM
According to this: http://linkingweatherandclimate.com/ocean/waterdensity.php (http://linkingweatherandclimate.com/ocean/waterdensity.php)
it seems that increasing salinity lowers the temperature at which maximum density is achieved.
Title: Re: Stupid Questions :o
Post by: Vergent on July 29, 2013, 09:50:11 PM
I understand that the maximum density of fresh water occurs at 3.98C. Would seawater also reach it's maximum density at this temperature assuming salinity remained constant?


Terry
Terry,

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fnsidc.org%2Fcryosphere%2Fseaice%2Fimages%2Fsalinity_graph.gif&hash=66441a4a71239b185d6984a136b2751b)

Vergent
Title: Re: Stupid Questions :o
Post by: birthmark on July 30, 2013, 11:47:10 AM
I have what is probably a stupid question. Why was 15% chosen as the standard of measurement for sea ice area and extent? Is there a physical reason or is it merely an arbitrary choice that has been accepted for the sake of consistency?

TIA
Title: Re: Stupid Questions :o
Post by: anonymous on July 30, 2013, 12:09:50 PM
I have what is probably a stupid question. Why was 15% chosen as the standard of measurement for sea ice area and extent? Is there a physical reason or is it merely an arbitrary choice that has been accepted for the sake of consistency?
The satellite sensors and the algorithms have to distinguish land and open water from sea ice. Under some conditions (coastlines, weather) they reported sea ice where it was proven none exists. 15% was a good trade-off between accuracy (report real ice) and usefulness (navigation).
Title: Re: Stupid Questions :o
Post by: birthmark on July 30, 2013, 02:24:49 PM
I have what is probably a stupid question. Why was 15% chosen as the standard of measurement for sea ice area and extent? Is there a physical reason or is it merely an arbitrary choice that has been accepted for the sake of consistency?
The satellite sensors and the algorithms have to distinguish land and open water from sea ice. Under some conditions (coastlines, weather) they reported sea ice where it was proven none exists. 15% was a good trade-off between accuracy (report real ice) and usefulness (navigation).
Thanks, a***!
Title: Re: Stupid Questions :o
Post by: Chuck Yokota on August 13, 2013, 07:49:13 PM
I notice that when an isolated ice floe melts away, in the satellite photos there remain for a couple of days streamers of a white substance that appear to be in the water (at least don't move with the clouds).  These make swirly patterns that can be many kilometers across.  What is this stuff?  Ice? Foam? Fog? Something else?  What would it look like from sea level?
Title: Re: Stupid Questions :o
Post by: Espen on August 13, 2013, 08:03:20 PM
I would call them sea ice contrails ;) (Not knowing the the official name)
Title: Re: Stupid Questions :o
Post by: Vergent on August 13, 2013, 08:23:02 PM
I notice that when an isolated ice floe melts away, in the satellite photos there remain for a couple of days streamers of a white substance that appear to be in the water (at least don't move with the clouds).  These make swirly patterns that can be many kilometers across.  What is this stuff?  Ice? Foam? Fog? Something else?  What would it look like from sea level?

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Ficefloe.net%2FAloftcon_Photos%2Falbums%2F2013%2F20130803-1701.jpeg&hash=c0b6ec267c986370852b482bdac18c2a)

Vergent
Title: Re: Stupid Questions :o
Post by: jdallen on August 14, 2013, 09:04:54 AM
I notice that when an isolated ice floe melts away, in the satellite photos there remain for a couple of days streamers of a white substance that appear to be in the water (at least don't move with the clouds).  These make swirly patterns that can be many kilometers across.  What is this stuff?  Ice? Foam? Fog? Something else?  What would it look like from sea level?
[image snipped]

Vergent

*Thats* what I've been seeing...
Title: Re: Stupid Questions :o
Post by: Glenn Tamblyn on August 14, 2013, 01:40:24 PM
Argh. Aloft Con on the Healy isn't giving Lat/Long....
Title: Re: Stupid Questions :o
Post by: Vergent on August 14, 2013, 02:40:53 PM
Argh. Aloft Con on the Healy isn't giving Lat/Long....

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Ficefloe.net%2FAloftcon_Photos%2Falbums%2F2013%2F20130814-1201.jpeg&hash=a1d622d463a6f149c1cf86724289646c)

Actually, they have fixed it. But the fix is not retroactive.

V
Title: Re: Stupid Questions :o
Post by: Anne on August 16, 2013, 11:29:38 PM
OK, stupid questions 101: How will we know when or what the minimum sea ice area is?
(Clouds, etc)

NSIDC's ruling is final. No correspondence will be entered into.

But, but?
Title: Re: Stupid Questions :o
Post by: Neven on August 17, 2013, 12:57:14 AM
OK, stupid questions 101: How will we know when or what the minimum sea ice area is?
(Clouds, etc)

NSIDC's ruling is final. No correspondence will be entered into.

But, but?

Anne, in September we look at the weather forecasts. As soon as low pressure areas take over for a prolonged time, we can be pretty certain that area/extent on most graphs will start to gain. Only a high over the Beaufort, combined with a low over the Siberian seas can cause some final melt, compaction and transport that prolong the melting season, but no further than the end of September.
Title: Re: Stupid Questions :o
Post by: Anne on August 17, 2013, 08:24:44 AM
Sure, I realise it won't go later than that! I'm just curious about the disagreements between the various systems of measurement, and how satellite data are compared with ground truth data. What actually happens at the end of the season when all this is wrapped up? Will  Bremen agree with NSIDC?
Title: Re: Stupid Questions :o
Post by: Marc on August 18, 2013, 10:37:20 PM
Vergent,

I'm new, so please bear with me.

I had asked this in another thread, but since Anne had asked the importance of water temperature previously, and you have given an excellent explanation of ocean currents recently, I'll ask you.

What is the relevance of air temperature when water has a factor of 2-3 times in heat carrying capacity?  (not to mention the greater surface are below ice).

Also, is the Arctic Ocean a true ocean, or is it a Mediterranean Sea because of the limitations of the Pacific inlet.  What is the turn-over rate as compared to similar bodies of water?

Thanks, and appreciate your patience.

Marc
Title: Re: Stupid Questions :o
Post by: Andreas T on August 19, 2013, 02:03:07 AM
I'll try to answer that from some basic physics and reading around on wikipedia and the like. Water would have a much larger effect than air on the ice if it had the same temperature difference from the melting point and the same flowrate past the ice. Over large parts of the arctic ocean warm currents don't get near the ice because they are saltier, denser and therefore some 150m down. Where water is warmed by the sun nearer the surface it does have a strong melting effect.
Your other question on the "short and medium term thread" seems to apply ideal gas law to a liquid? pv = nRT also can not determine temperature from pressure because volume is free to change. With heat transfered from an external source of energy pressure and temperature can theoretically take any value.
Title: Re: Stupid Questions :o
Post by: Vergent on August 19, 2013, 02:42:13 AM
Marc,

The air is a significant factor only if it has a dew point that is different from 0C. If it is above 0C condensation is occurring, and one gram of condensation will melt 6.76 grams of ice. Air has a low heat capacity the amount of heat transfer from cooling the air down to zero is insignificant compared  to the condensation dropping the dew point. If the dew point is significantly below zero, then any exposed water will chill rapidly due to evaporation.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2Fa8LdO6I.png&hash=266677e36afd938c6299a463b9c36840)

http://www.instantweathermaps.com/GFS-php/nh.php (http://www.instantweathermaps.com/GFS-php/nh.php)



The normal convective air flow is from the cold to the warm, like on a beach in summer. So at the edge of the ice in the absence of a strong weather pattern, you do not get much melting from the air. But, of late there have been "dipole anomalies"(a high and low paired up an relatively stationary) and arctic cyclones that can overcome the local convection and torch the ice with warm moist air.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FLBlUtkM.png&hash=6b1008f8e7d2beef56331ecf32fcf510)

The AO index is a measure of the vorticity of the arctic cell. A positive AO means there is a net cyclonic airflow a negative AO means a net anti-cyclone. A positive AO is considered to be favorable for melting and negative unfavorable. The long negative AO in July and early Aug. accompanied a slowdown in melting.

Vergent
Title: Re: Stupid Questions :o
Post by: jdallen on August 19, 2013, 04:14:28 AM
The air is a significant factor only if it has a dew point that is different from 0C. If it is above 0C condensation is occurring, and one gram of condensation will melt 6.76 grams of ice. Air has a low heat capacity the amount of heat transfer from cooling the air down to zero is insignificant compared  to the condensation dropping the dew point. If the dew point is significantly below zero, then any exposed water will chill rapidly due to evaporation.

Nicely put!  Thanks for the numbers and insight, Vergent.
Title: Re: Stupid Questions :o
Post by: seattlerocks on August 19, 2013, 09:17:32 AM
Vergent, thanks very much for your explanation. If I understand well the GFS map you just posted, the warm air flow from Europe toward Central Arctic that some contributors are noting won't probably hurt ice much, don't you think?
Title: Re: Stupid Questions :o
Post by: Andreas T on August 19, 2013, 11:06:20 PM
 
Air has a low heat capacity the amount of heat transfer from cooling the air down to zero is insignificant compared  to the condensation dropping the dew point. If the dew point is significantly below zero, then any exposed water will chill rapidly due to evaporation.
what surprises me in that statement is that at about 0 deg C partial pressure of water is very low, so one m3 of (saturated) air (=1.29kg) cooled from 3deg C to 0degC yields 1.6 g of liquid water condensation. Put in heat capacities and latent heat and you get 10.8g of ice melted from condensation and 11.6g of ice melted from temperature change in air.
Or am I getting something wrong?
Evaporation similarly requires large quantities of air to evaporate significant amounts of water as water content changes not that much from lower to higher dewpoint.
Condensation and evaporation clearly play an important role but not a dominant one it seems to me.
Title: Re: Stupid Questions :o
Post by: Vergent on August 20, 2013, 07:20:42 AM
Air has a low heat capacity the amount of heat transfer from cooling the air down to zero is insignificant compared  to the condensation dropping the dew point. If the dew point is significantly below zero, then any exposed water will chill rapidly due to evaporation.
what surprises me in that statement is that at about 0 deg C partial pressure of water is very low, so one m3 of (saturated) air (=1.29kg) cooled from 3deg C to 0degC yields 1.6 g of liquid water condensation. Put in heat capacities and latent heat and you get 10.8g of ice melted from condensation and 11.6g of ice melted from temperature change in air.
Or am I getting something wrong?
Evaporation similarly requires large quantities of air to evaporate significant amounts of water as water content changes not that much from lower to higher dewpoint.
Condensation and evaporation clearly play an important role but not a dominant one it seems to me.

Are you sure?

Vergent



Title: Re: Stupid Questions :o
Post by: Richard Rathbone on August 20, 2013, 08:31:48 AM
The tables I checked gave 2.0 g/m3 difference between 0 and 5C

Latent heat is very close to 2500 kJ/kg at 0C so 2g gives 5 kJ

Specific heat of air is very close to 1 kJ/kg.K so cooling 1.3 kg by 5K gives 6.5 kJ

They do indeed contribute pretty much the same.
Title: Re: Stupid Questions :o
Post by: Andreas T on August 20, 2013, 08:47:11 AM
The numbers I used are are:
partial pressure of water vapour at 273K: 6mb; at 276K 8mb
at total pressure of 1000mb that is 0.2 % Vol change in water content i.e. 1m3of air yields 2l of water vapour or 1.6g of liquid water. You give 6.67g of ice melt per g of condensation, density of air 1.29kg/m3 and heat capacity 1.005 kJ /kg K give 3.9kJ for temp change from 276K to 273K. 334J melt one g of water.

Richard wrote pretty much the same as I was typing but I hope he doesn't mind me repeating.
Title: Re: Stupid Questions :o
Post by: Vergent on August 20, 2013, 03:19:31 PM
What would happen if the air was dry?

Vergent

Edit; Why do people in Palm Springs turn on the fan when the air is warmer than they are?
Title: Re: Stupid Questions :o
Post by: Andreas T on August 20, 2013, 06:34:02 PM
In terms of melt I think these numbers mean that air at 3deg C with dew point of 3deg C dewpoint can melt  about twice as much ice as air at 3deg C with dew point of 0deg C. That means humidity definitely matters just not overwhelmingly so. To work out what air at dewpoints below 0deg C does thing get more complicated. I guess air could become saturated with water vapour from sublimation which brings air temperature in the boundary layer down to 0deg C without melting ice, because air with a dew point of say -20deg C  (partial pressure 1mb) would require the all the heat from its temperature change to sublimate water vapour to reach saturation.
I think you have made your point, very dry air of temperatures not too much above 0 deg C would not melt ice at all.
Thats me working from basic principles, if somebody has actual observations I am happy to be shown the error of my ways.
Title: Re: Stupid Questions :o
Post by: epiphyte on August 20, 2013, 08:30:08 PM
Is there any validity to the assumption that under melting conditions, the rate of volume loss varies with the top and/or bottom surface area – I.e. when conditions are favorable, the larger the area, the faster volume is lost? If so could we not still be in for a surprise?

Viz: If I’m reading the numbers right the ice area at this time in 2008 was very similar to today.  But the subsequent volume loss to minimum was much bigger than other recent years.Viz: PIOMAS volume (KKm**3):

                   2008     2013
day 212  - 11.255  7.104
day 261  -  7.002    ?
change     -4.151

but in 2008, the volume was much bigger than today - If the same loss rate were to be repeated this year, we would finish with record low volume (2.953Kkm**3)

Spread evenly over 6Mkm**2 (incorrect I know, but I’d guess optimistic w.r.t the prognosis for lower-latitude/FYI) that would correspond to an average reduction in ice thickness of 1.445M.

Most of the ice isn’t that thick -  Looking at HYCOM from today and subtracting 1.4M from the thickness I don’t see that this year is over yet – or even that another record loss is yet out of the question. Where am I going wrong?
Title: Re: Stupid Questions :o
Post by: Vergent on August 20, 2013, 11:54:56 PM
Andreas'

I asked about dry air. 3C air with 0C dew points is still quite moist. So, lets take -10 air from the summit of Greenland and slide it down the slope onto the ice. Through compression, it has warmed up to 3C, but it has a dew point of -10C. What happens when this dry air hits the meltponds and leads? Which way will the energy flow? From the air to the water? No! Evaporation must happen. A little energy for this evaporation will come from the air, a lot will come from the water.

When air and water interact almost always either net condensation or net evaporation is happening. You chose the single point where that was not true.

Vergent



Title: Re: Stupid Questions :o
Post by: Richard Rathbone on August 21, 2013, 05:37:19 AM
What would happen if the air was dry?

Vergent

Edit; Why do people in Palm Springs turn on the fan when the air is warmer than they are?

They turn on the fan because the wet bulb temperature is cooler than they are.

There is a competition between increased transport of heat from the air to the skin, against increased transport of evaporated sweat away. The wet bulb temperature is the temperature at which these transport rates balance. Moist surfaces above the wet bulb temperature will be cooled, and those below it will be heated. Increasing the convection increases the effect.

If the wet bulb temperature is higher than you are, you aren't going to live long, and turning on the fan will just kill you quicker.

The drier the air, the lower the wet bulb temperature.

If air at 3C has a wet bulb temperature of -2C when the artic surface temperature is -1C there is net cooling, and if the wet bulb temperature is 0C there is net heating of the surface.
Title: Re: Stupid Questions :o
Post by: Vergent on August 21, 2013, 06:06:52 AM
Richard,

+

Everything you said was correct, keep up the good work! The temperature does not dictate the heat flow, the dew point does.

Vergent
Title: Re: Stupid Questions :o
Post by: Marc on August 22, 2013, 02:35:06 AM
Vergent,

"The air is a significant factor only if it has a dew point that is different from 0C. If it is above 0C condensation is occurring, and one gram of condensation will melt 6.76 grams of ice. Air has a low heat capacity the amount of heat transfer from cooling the air down to zero is insignificant compared  to the condensation dropping the dew point. If the dew point is significantly below zero, then any exposed water will chill rapidly due to evaporation."

Then water temp has much more capacity for heat transfer.

Curious where you stand with what you think is significant driver for causing increased melt (over last decade).  My stand is that it that it's coming from bottom.  I'd say further that I don't think it's the melt, it's the refreeze because the heat in water limits it.  Your understanding of weather/atmosphere is very impressive in discussions above.  What's your best guess?  is it water temp or weather?

Thanks for taking time to respond to me, and thanks for discussion above that was educational.
Title: Re: Stupid Questions :o
Post by: jdallen on August 22, 2013, 08:43:19 AM
I bet on water temp, by a combination of steadily increased ocean enthalpy reducing the time required for melting to start, combined with the main driver, Seasonal solar heating of arctic surface water.
Title: Re: Stupid Questions :o
Post by: Vergent on August 22, 2013, 05:30:35 PM
Marc,

As I see it;


All of these increase the energy in the arctic. The actual melting of the ice is just the second law of thermodynamics. The primary cause is the GHG. The rest are positive feedbacks.

Vergent

Title: Re: Stupid Questions :o
Post by: Marc on August 28, 2013, 12:11:50 AM
Thanks Vergent,
Not quite the answer I wanted, but can't tell you how much I appreciate your posts.  Your insight is appreciated.  Especially when it's in the middle of arguments between theoreticians and statisticians.  Always great comments.

Thanks
Title: Re: Stupid Questions :o
Post by: johnm33 on November 22, 2013, 05:52:21 PM
Does co2 [+ch4 for that matter] have the same energy retaining effect when dissolved in the ocean, and did we cross a threshold 15 years ago when the oceans began to soak up more heat.
Title: Re: Stupid Questions :o
Post by: jdallen on November 22, 2013, 07:06:01 PM
Does co2 [+ch4 for that matter] have the same energy retaining effect when dissolved in the ocean, and did we cross a threshold 15 years ago when the oceans began to soak up more heat.

No, it does not.  GHG effects are the result of their being "opaque" to the transmission of certain wavelengths of light, in particular various IR wavelengths.  These line up more or less squarely with the black body emissions at the earths surface, as it absorbs sunlight, and the re-radiates the "heat".

QED, "visible" spectra - that not blocked by GHG's - passes through, gets absorbed, but the re radiated light - considerably increased in wavelength - is blocked and partially trapped.  GHG's do not heat so much as they selectively insulate.

So, once picked up by water, they no longer present a barrier, or affect the *Kinetic* exchange of energy between ocean and atmosphere.
Title: Re: Stupid Questions :o
Post by: johnm33 on December 02, 2013, 12:59:18 PM
jdallen thanks for that reply, here's another physics type question.
If it were possible to shift a cube of ice [say 1m3 at -10C] instantly from the north pole to 60deg N and it was constrained from moving what effects would be expected?
Title: Re: Stupid Questions :o
Post by: jdallen on December 03, 2013, 10:38:02 AM
jdallen thanks for that reply, here's another physics type question.
If it were possible to shift a cube of ice [say 1m3 at -10C] instantly from the north pole to 60deg N and it was constrained from moving what effects would be expected?

Sounds like a physics exam question. ;)

As the difference in velocity between the block and ground would be several hundred KPH, I'd say there would be a lot of crushed ice ;)
Title: Re: Stupid Questions :o
Post by: Andreas T on December 03, 2013, 01:51:46 PM
If you could explain why you are asking this question and what sort of possible effects you are interested in, John, it would make it easier and more worthwhile for someone to try to answer it.
For example 60 deg latitude covers a lot of different places, with different climate, guessing how quickly that ice would melt obviously depends on that. Locally it would cool and dilute the surface water if placed in the sea. If floating in the sea it would not change mass distribution as far as I know, and sea level only slighly by moving less dense water south and more dense (saltier) water north to take its place.
Title: Re: Stupid Questions :o
Post by: johnm33 on December 03, 2013, 04:51:06 PM
I'm wondering how much energy has to be acquired between the pole and southern greenland, clearly a lot of kinetic energy but how does that translate in terms of temperature. What I want to think about is how much energy is soaked up or shed by the ice as it moves south or north when constrained by the pack.  It may have been better to ask about the imaginary cube going from 60degN to the pole. 
Title: Re: Stupid Questions :o
Post by: Andreas T on December 03, 2013, 09:26:54 PM
Of course moving floating ice from north to south will mean water of equal mass will take its place in the north and will be displaced in the south. The increase in rotational speed which means a gain in kinetic energy for the ice is balanced by a reduction of the rotational speed and kinetic energy of the water moving north. The change in velocity components in an rectangular coordinate system (in which Newtonian mechanics can be applied) are in balance at any time and momentum is conserved since no external forces (external to earth as a whole) act. During the process of movement kinetic energy would of course be higher for both masses by the north south component of their movement but would be dissipated before coming to rest. This energy would be provided by the sun (in any realistic scenario) and has the same heat input into the earth system whether the movement takes place (heat producing work then dissipated as heat) or not (heat remaining heat).
Title: Re: Stupid Questions :o
Post by: Andreas T on December 04, 2013, 11:50:32 PM
when ice is removed from land, mass distribution changes:
http://www.nature.com/news/polar-wander-linked-to-climate-change-1.12994 (http://www.nature.com/news/polar-wander-linked-to-climate-change-1.12994)


Title: Re: Stupid Questions :o
Post by: johnm33 on December 05, 2013, 10:50:00 PM
Andreas T I had a go at the calcs. myself, with low confidence, I reckon that each m3 of ice needs to soak up about 7mj per kilometer as it moves south, so if there's no sun reaching the surface, a cyclone near the pole should cause anomalous cooling. It makes sense that the bottom currents, heading south, should begin in the greenland sea, since the atlantic waters here surrender their heat to the surface waters/ice flowing south, and when there's little flow through Fram those same atlantic waters penetrate further north to shed their 7mj
Title: Re: Stupid Questions :o
Post by: jdallen on December 06, 2013, 09:51:24 AM
Andreas T I had a go at the calcs. myself, with low confidence, I reckon that each m3 of ice needs to soak up about 7mj per kilometer as it moves south, so if there's no sun reaching the surface, a cyclone near the pole should cause anomalous cooling. It makes sense that the bottom currents, heading south, should begin in the greenland sea, since the atlantic waters here surrender their heat to the surface waters/ice flowing south, and when there's little flow through Fram those same atlantic waters penetrate further north to shed their 7mj
  • .
That energy isn't picked up as heat; it's picked up by way of angular momentum.  There isn't a lot of loss to friction.  Contrary-wise, the same mass of water (or air) moving north sheds that momentum.
Title: Re: Stupid Questions :o
Post by: johnm33 on December 13, 2013, 12:28:00 PM
I can't accept your assertion, the Atlantic waters flowing north shed most of their inertia/kinetic energy in Barents and the Kara. All the graphics and studies i've read show the southbound cold waters gathering in the Greenland sea, with a little input flowing out at depth through Fram and a larger contribution falling off the continental shelf between Svalbard and Norway, but mostly it appears to be 'created' in situ. Also it's implicit in the explanations i've read that energetic content is fully transferable between heat, kinetic and potential energy, so I imagine that somehow it's reflected in the molecular or atomic state of the actual material.
 As the ice passes through Fram and is driven south, it clearly 'wants' to head west [according to accepted theories] but can't because of Greenland, it's also moving away from the axis of rotation on a great arc so i would expect it to be far from equilibrium, and I suspect in energy deficit. The currents heading north have the opposite 'tension' leading to all the complex vortexes along the coast, which serve to refine, differentiate and resolve the potential energies present. Somewhat like the EKE in the Labrador sea.
This still doesn't resolve the question though, does ice[NH] cool as it moves south? and warm as it moves north? that is does it find itself with a potential energy deficit/excess. This would help to make sense of this summers cooling, even as the ocean was exposed when the ice was pushed apart. It would also help explain why the HYCOM CICE so often shows ice growing suddenly thicker when atmospheric conditions don't appear conducive.
Title: Re: Stupid Questions :o
Post by: jdallen on December 14, 2013, 12:22:32 AM
There is a balance in displacement, otherwise, water & atmosphere volume would stack up at the poles or equator.

The kinetic energy shed or gained is imparted to either atmosphere or ocean, pushing air or water out of the way.  It is not lost to friction.   Air moving north loses momentum to air moving south.  Water moving north loses momentum to water moving south.  As noted above, equal masses are displaced, so  Loss to friction is trivial. Energy is conserved.

Part of your problem is frame of reference.  Any mass moving perpendicular to the axis of a rotating planet, and maintaining near equal angular velocity is in fact undergoing continuous acceleration or deacceleration, depending on direction.  That continuous acceleration is where your energy is going, not to heat. You don't see this from a frame of reference on the ground, as the speed of the moving medium maintains consistent velocity relative to the earths surface, the velocity of which itself changes smoothly with distance from the equator.
Title: Re: Stupid Questions :o
Post by: johnm33 on December 14, 2013, 01:08:02 PM
Now we're getting somewhere, it's the energy loss to the continuous acceleration/ gain from continuous deceleration that i wanted to quantify.
No doubt it's all in some kind of dynamic balance, but the processes occur in separate locations to some extent, and where the water is free to writhe to express it's energetic 'discomfort' the ice is stuck on the surface led at the whim of wind and currents. 
Title: Re: Stupid Questions :o
Post by: Shared Humanity on December 14, 2013, 03:55:21 PM
There is a balance in displacement, otherwise, water & atmosphere volume would stack up at the poles or equator.

The kinetic energy shed or gained is imparted to either atmosphere or ocean, pushing air or water out of the way.  It is not lost to friction.   Air moving north loses momentum to air moving south.  Water moving north loses momentum to water moving south.  As noted above, equal masses are displaced, so  Loss to friction is trivial. Energy is conserved.

Part of your problem is frame of reference.  Any mass moving perpendicular to the axis of a rotating planet, and maintaining near equal angular velocity is in fact undergoing continuous acceleration or deacceleration, depending on direction.  That continuous acceleration is where your energy is going, not to heat. You don't see this from a frame of reference on the ground, as the speed of the moving medium maintains consistent velocity relative to the earths surface, the velocity of which itself changes smoothly with distance from the equator.

Another stupid question........I thought water did stack up at the equator as a result of the earth's rotation? Did I read somewhere that as land ice melts, the sea level rise would be relatively higher as you move towards the equator? 

This is a particularly stupid question as I am asking others whether I read something somewhere. ::)
Title: Re: Stupid Questions :o
Post by: Andreas T on December 14, 2013, 04:15:59 PM
The main problem with your idea that water cools as it increases its kinetic energy is that this kinetic energy can not come directly from its heat energy. This is the most diffuse form of energy so energy transfer would be from kinetic to heat (through "friction" i.e. dissipation of bulk movement to radom molecular movement) not the other way round. This is basically dictated by the second law of thermodynamics.
That does not mean that movement isn't driven by heat input. This heat input (basically from the sun) produces density and pressure differences in water and air, which produces the forces necessary to accelerate water in any direction.
How this operates in any given location is complex and of course movement of water into the arctic basin along the european land mass must be connected by pressure distibution to outflows of abyssal cold water and low salinity surface water along the greenland coast.

Shared Humanity: yes sea level rise is larger at the equator but remember that there is already a higher elevation of the water level, so additional water will raise levels at equator  and poles proportionally. An added effect is that mass lost from Greenland and Antarctica reduces the gravitational pull towards these masses which also reduces sealevel rise near these costs (assuming all else remaining equal)
The presence of these coasts means water has to have  the same (eastward) rotational speed as the coast or it will be pushed up (increasing pressure at depth) which provides the pressure gradients which accelerate and redirect ocean currents.
Changes in currents and water temperatures are of course a major cause of changes along the east coast of Greenland, but the connection of movement and temperature is not as direct as you seem to think, John.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on January 03, 2014, 06:24:56 PM
I have been watching Cryosphere Today daily for a couple of years. Over the past couple of weeks, it has been showing fairly significant loss of snow cover over Europe, Scandinavia and eastern Europe in particular. There are now large patches appearing across the  midsection of Russia. This snow cover loss is now showing up in Alaska as well. How accurate are these images and, if accurate, is the current snow cover typical for this time of year?




http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png (http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png)
Title: Re: Stupid Questions :o
Post by: crandles on January 03, 2014, 06:39:17 PM
Rutgers seems to agree on there being little snow in Europe:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F128.6.226.99%2F%7Enjwxnet%2Fpng%2Fdaily_dn%2F2014002.png&hash=dcefeda6685cdabd0c45c858eb41f7d6)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F128.6.226.99%2F%7Enjwxnet%2Fpng%2Fdaily_ims%2F2014002.png&hash=4485b56cf715bcf472398797b0994f98)

http://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2014&ui_day=2&ui_set=0 (http://climate.rutgers.edu/snowcover/chart_daily.php?ui_year=2014&ui_day=2&ui_set=0)

but " large patches appearing across the  midsection of Russia" ??

(I take grey areas to mean cloud cover is too thick to see but am not sure that is correct interpretation. So, Russia looks pretty well covered to me in image linked. I also assume it shows extent of snow cover but that there isn't information on thickness - could be just a bit of a ground frost or 3m thick snow.)

Rutgers does have a legend :)
Title: Re: Stupid Questions :o
Post by: jdallen on January 03, 2014, 09:57:40 PM
I believe the Siberia reports were earlier in December, and limited to southern areas. I can't speak to snow depth, outside of my region (US Pacific NW) which currently has only about 35% of its usual snow pack.
Title: Re: Stupid Questions :o
Post by: lanevn on February 10, 2014, 07:05:42 AM
What's happened to arctic part of https://earthdata.nasa.gov/labs/worldview/?
Title: Re: Stupid Questions :o
Post by: johnm33 on February 10, 2014, 03:57:17 PM
Night?
Title: Re: Stupid Questions :o
Post by: idunno on February 10, 2014, 05:23:12 PM
What is it with Dutch people and ice?

http://www.theguardian.com/sport/2014/feb/10/sochi-2014-winter-olympics-day-three-live (http://www.theguardian.com/sport/2014/feb/10/sochi-2014-winter-olympics-day-three-live)

Neven's bad enough.
Title: Re: Stupid Questions :o
Post by: lanevn on February 10, 2014, 05:26:25 PM
Night?
Oh, .... That were really stupid. Ty.
Title: Re: Stupid Questions :o
Post by: Theta on February 14, 2014, 07:14:54 AM
I apologise for bringing this up again, but I just wanted to know, since people appear to be getting worried about the Arctic ice, if there was a possibility of the ice continuing on its present track, very little gains and minor losses, and bring about a disastorous melt season with perhaps an early complete melt out of the Arctic Sea Ice altogether regardless of the gains made in the area of volume, I guess with the current diving in extent and area it is likely that the volume of the ice must be deteriorating at this point too.
Title: Re: Stupid Questions :o
Post by: jdallen on February 14, 2014, 08:38:24 AM
I apologise for bringing this up again, but I just wanted to know, since people appear to be getting worried about the Arctic ice, if there was a possibility of the ice continuing on its present track, very little gains and minor losses, and bring about a disastorous melt season with perhaps an early complete melt out of the Arctic Sea Ice altogether regardless of the gains made in the area of volume, I guess with the current diving in extent and area it is likely that the volume of the ice must be deteriorating at this point too.
In the current regime in the arctic, there is always the possibility.  I'm cautious about making that kind of prediction however considering my track record over the last few years.  I have learned, that making sweeping predictions are almost certain to result in failure.

A "dive" is not yet certain.  Current events make it more probable, but it is not yet a "given". 

Considering recent years and the vicissitudes of climate events elsewhere on the globe, our ability to predict is still far from certain.  Consider, that current models did not see anything like 2007, much less 2012, before mid century.  We are learning a lot, very fast, and its not particularly comfortable.

Yes, I am concerned, but there is an awful lot that still needs to fall into place before we can conclude that 2014 will be a new record low for ice extent, area and volume.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on February 18, 2014, 06:32:31 AM
Now this can't be right, can it?
Title: Re: Stupid Questions :o
Post by: jdallen on February 18, 2014, 08:36:38 AM
Now this can't be right, can it?


Can't say either way, Pmt.

I have no idea how the curves are being generated, what data they represent, what the hyperbolic curve is tied to, or what any of the dimensions are.  My best guess with any of that is a curve fit to data.  Unfortunately, my experience of curve fitting to unpredictable phenomena is... unpredictable ;)

If you are making broad suggestions that the current ice state is leading to a catastrophe, I'm afraid I've got no way to make that prediction from our current data - only that it is declining far more rapidly than predicted, and does suggest we'll see an "ice free" arctic in the near future.  Outside of that, my crystal ball is still rather opaque.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on February 19, 2014, 03:52:15 AM
well, yes, there's still thicker and thinner sections in the arctic sea ice so such straightforward extrapolation cannot be correct. and the fact that the form of the curve may well be different. that one isn't even parabolic.
Title: Re: Stupid Questions :o
Post by: jdallen on February 19, 2014, 06:19:11 AM
well, yes, there's still thicker and thinner sections in the arctic sea ice so such straightforward extrapolation cannot be correct. and the fact that the form of the curve may well be different. that one isn't even parabolic.

The curve regardless of type presumes a consistent trend.  I'm a long way from thinking that is likely.  I don't think the progression, whether sooner, or later, will be that smooth, and I think "sooner" is a realistic possibility.
Title: Re: Stupid Questions :o
Post by: Anne on March 23, 2014, 08:32:59 PM
Here's a really stupid question. Why does a surface sometimes appear as if it's been compressed under a sheet of glass, so that only depressions show? An example here, from Zachariae Isstrøm (http://forum.arctic-sea-ice.net/index.php/topic,400.msg22630.html#msg22630). I'm guessing it's something to do with digital recording, rather than an actual feature of the landscape.
Title: Re: Stupid Questions :o
Post by: pikaia on March 23, 2014, 11:43:07 PM
Here's a really stupid question. Why does a surface sometimes appear as if it's been compressed under a sheet of glass, so that only depressions show? An example here, from Zachariae Isstrøm (http://forum.arctic-sea-ice.net/index.php/topic,400.msg22630.html#msg22630). I'm guessing it's something to do with digital recording, rather than an actual feature of the landscape.

It is an optical illusion. The light is coming from the bottom, but we are used to seeing light coming from the top, so the apparent depressions are actually higher ground. If you rotate the image 180 degrees you will see what I mean.
Title: Re: Stupid Questions :o
Post by: Anne on March 23, 2014, 11:59:34 PM
Thanks, pikaia. I see what you mean.

But to turn the question upside down: I'm still puzzled - by the uniform flatness of what turns out to be the lower elevation.
Title: Re: Stupid Questions :o
Post by: crandles on March 24, 2014, 12:22:28 AM
Umm is this too obvious: a lack of elevations below sea level because water finds its way there, and when the sea freezes it is usually pretty flat unless deformed into ridges?

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D400.0%3Battach%3D4009%3Bimage&hash=03ad867615669b823084b3465f70e8d7)
Title: Re: Stupid Questions :o
Post by: Anne on March 24, 2014, 12:27:35 AM
Well, yes, but doesn't it get blown and pushed about? But I guess that is the answer, and that minor deformations don't show because of the scale. (Told you it was a stupid question!)
Title: Re: Stupid Questions :o
Post by: Wipneus on March 24, 2014, 07:43:04 AM
Anne, my thought was that you may be confused as well by the mist/fog patches that lie on the glacier. I am, and hope for an even more clear day for an even more brilliant image.
Title: Re: Stupid Questions :o
Post by: icefest on April 06, 2014, 04:21:54 PM
This question is not about Arctic Sea Ice per se, but it still is a stupid question so I though this is where it would best fit in.

The reason people are keeping watch on Tropical Cyclone development in the El Nino thread is because we'd expect less of them in the WPAC and more in the EPAC. Is this right?
Title: Re: Stupid Questions :o
Post by: jdallen on April 06, 2014, 07:59:24 PM
This question is not about Arctic Sea Ice per se, but it still is a stupid question so I though this is where it would best fit in.

The reason people are keeping watch on Tropical Cyclone development in the El Nino thread is because we'd expect less of them in the WPAC and more in the EPAC. Is this right?

Yes and no.  Changes in cyclone development are an effect of the cyclical El Niño/La Niña behavior, so following those can provide a clue as to which direction the momentum of the system is going.  There is also a horrified fascination with the rising intensity and frequency of storms in the western Pacific.  On the close order of two billion people live across the affected region; we have a lot to be concerned about....
Title: Re: Stupid Questions :o
Post by: wanderer on April 08, 2014, 08:23:53 AM
Stupid Question #1920:

Why is arctic sea ice volume still growing and sees its max in April, whereas extent and area see their max in March?
Title: Re: Stupid Questions :o
Post by: icefest on April 08, 2014, 09:42:06 AM
Because area depends on the temperatures at the fringes (at it's most southerly extent)
and Volume at the total melt/freeze rate.

This means that the cold north pole might still be getting thicker while spring has arrived in newfoundland.
Title: Re: Stupid Questions :o
Post by: Stephen on April 14, 2014, 01:23:46 AM
Regarding daily numbers and graphs from the usual suspects (NSIDC, IJIS/JAXA, CT), do any of them take "Sundays off" from their reporting?

I seem to remember that, a few years ago, NSIDC didn't update their numbers on a Sunday.  Just looking at the latest CT area, it does not seem to have been updated for 48 hours.

And could someone provide a list of when the numbers are typically updated for each site (in GMT).
Title: Re: Stupid Questions :o
Post by: Jim Hunt on April 14, 2014, 09:44:57 AM
And could someone provide a list of when the numbers are typically updated for each site (in GMT).

I'm intrigued to know why you ask these questions Stephen? As a partial answer, keep a close eye on the IJIS/JAXA (http://forum.arctic-sea-ice.net/index.php/topic,230.0.html) and Area and Extent (http://forum.arctic-sea-ice.net/index.php/topic,230.0.html) threads.

The JAXA numbers seem to come out when they're at work in Japan (i.e. early morning UTC). NSIDC/CT numbers seem to come out when they're at work in Colorado. (i.e. mid/late afternoon UTC)
Title: Re: Stupid Questions :o
Post by: Stephen on April 14, 2014, 10:16:05 AM
And could someone provide a list of when the numbers are typically updated for each site (in GMT).

I'm intrigued to know why you ask these questions Stephen? As a partial answer, keep a close eye on the IJIS/JAXA (http://forum.arctic-sea-ice.net/index.php/topic,230.0.html) and Area and Extent (http://forum.arctic-sea-ice.net/index.php/topic,230.0.html) threads.

The JAXA numbers seem to come out when they're at work in Japan (i.e. early morning UTC). NSIDC/CT numbers seem to come out when they're at work in Colorado. (i.e. mid/late afternoon UTC)

No particular good reason, just curious. I do check those threads just after the sites.
I'm in the GMT +10 timezone and they are usually updated when I check in the morning.
Title: Short wavelength vs long wavelength
Post by: Buddy on April 21, 2014, 12:40:45 AM
Question for the physics inclined folks:  I know that light comes into the atmosphere from the sun in a "short wavelength".......and when hits the earth and is radiated back out towards space in "long wavelengths" (generally).

BUT.......my question is this:  If sunlight comes into the atmosphere from the sun and hits "white snow" (ie relatively "pure snow" and not snow with coal dust...or other dark particles).......is it REFLECTED back out of the atmosphere via SHORT WAVELENGTH.......OR is it still radiated back out in long wavelenth?

Thanks in advance........
Title: Re: Stupid Questions :o
Post by: Chuck Yokota on April 21, 2014, 02:55:20 AM
Buddy,
The reflected sunlight stays in the same short wavelengths as it arrived.  The fraction of sunlight reflected by the Earth is its albedo, which is accounted for separately from the energy that is absorbed and re-radiated.  It is only when the sunlight is absorbed by matter that it is radiated back out in the long wavelengths. 
Title: Re: Stupid Questions :o
Post by: icefest on April 24, 2014, 05:38:12 PM
Next stupid question:

RMM (Real-time Multivariate MJO) Index charts
How do I read these charts?
Other than saying "Yep, that's definitely a chart" there's not much else I can do.


  (https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fforum.arctic-sea-ice.net%2Findex.php%3Faction%3Ddlattach%3Btopic%3D730.0%3Battach%3D6441%3Bimage&hash=c09da60c869eb1d7a51b228afc058ec1)
Title: Re: Stupid Questions :o
Post by: opensheart on April 24, 2014, 06:49:27 PM
I don't really understand it either.

From what I can guess at, it kinda maps the Equator of the Earth.   The different sections are different parts of the Earth the Equator goes througth.    Section 1 begins with Longtitude 0 in Africa.  then as you move east you leave Africa and come to the Indian Ocean,  Which is the bottom two sections of the graph.   Then as you leave the Indian Ocean, you come to Indonesia and various Islands.   This is the right sections of the graph.   then when you clear the Islands you come to wide open ocean, which is the top sections of the graph.   
But here my idea breaks down, for if the top seconds are just the Western Pacific, then the last section, section 8, would have to cover the Eastern Pacific, South America, and the South Atlantic all the way back to Long 0 in Africa in one small section.  That's almost half the planet.   so my guess must be wrong.

I gather that the closer a point is to the center, the weaker 'it' is,  and the farther from the center the stronger 'it' is.   But I don't know what the center circle is suppose to represent.  Some sort of threshold perhaps?

Clarification and explaination from those who know would be appreciated.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on April 24, 2014, 06:58:59 PM
No help from me either... other than it appears this plots MJO around the globe though it usually is present only in Pacific and Indian Oceans. In Atlantic Ocean, so I've read, the pattern usually breaks down since North-South movements of ocean water are that much stronger here...
Title: Re: Stupid Questions :o
Post by: John_The_Elder on April 24, 2014, 06:59:50 PM
Hi folks,

Here is a link that describes the Madden Julian Oscillation (MJO)

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml#educational%20material (http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml#educational%20material)

John
Title: Re: Stupid Questions :o
Post by: Bruce Steele on April 24, 2014, 07:45:02 PM
Here is a animation that shows rain intensity . It also shows a clocklike blue pie-slice that corresponds to the MJO index chart we are used to seeing. So when rain intensity is highest in the Indian Ocean the pie-slice points 8 o' clock as the pie- slice moves counterclockwise to 4 o'clock the rain intensity moves eastward over Indonesea  12 o'clock enters Pacific and at 3 o'clock the Western Pacific. Because it is an occilation it moves back the the Indian Ocean rather than continuing into the Eastern Pacific or Atlantic.

 http://envam1.env.uea.ac.uk/mjo.html (http://envam1.env.uea.ac.uk/mjo.html)
Title: Re: Stupid Questions :o
Post by: icefest on April 24, 2014, 10:27:27 PM
I think i understand it now. Thanks to everyone that  answered!
Title: Re: Stupid Questions :o
Post by: ktonine on April 25, 2014, 06:41:13 AM
The original paper detailing the time series is  An All-Season Real-Time Multivariate MJO Index: Development of an Index for Monitoring and Prediction  (http://cawcr.gov.au/staff/mwheeler/abstracts/WH04.pdf), MATTHEW C. WHEELER AND HARRY H. HENDON, Bureau of Meteorology Research Centre, Melbourne, Australia (2004, American Meteorological Society).
Title: Re: Stupid Questions :o
Post by: Pmt111500 on April 25, 2014, 07:29:17 AM
ok, thanks, Bruce Steele, and others, so, to make it certain, the image in question shows a two week reversal of the general eastward progression of MJO in the beginning of the february, with associated waning (almost disappearing) of the oscillation?
Title: Re: Stupid Questions :o
Post by: seattlerocks on April 25, 2014, 11:52:42 AM
Why fast ice is called "fast"? To me it seems pretty slow
Title: Re: Stupid Questions :o
Post by: icefest on April 25, 2014, 11:58:11 AM
Because it's stuck 'fast' to the land.

Same word root as "fastener".



Quote
Old English fæst "firmly fixed, steadfast, secure, enclosed," probably from Proto-Germanic *fastuz (cognates: Old Frisian fest, Old Norse fastr, Dutch vast, German fest), from PIE root *past- "firm" (source of Sanskrit pastyam "dwelling place").
Title: Re: Stupid Questions :o
Post by: Anne on April 25, 2014, 12:23:58 PM
"Fast" is one of those words like "cleave" and "sanction", which can mean opposite things.
Title: Re: Stupid Questions :o
Post by: theoldinsane on April 25, 2014, 07:25:17 PM
I think it comes from the Danish "fast". Remember that Greenland belongs to Denmark. It is almost the same in Swedish.

Google translation from Swedish:

solid, fixed, rigid, firm, settled, permanent, immovable, unblinking, unshaken

choose what you like the best  8)

Title: Re: Stupid Questions :o
Post by: Espen on April 25, 2014, 08:16:08 PM
It is very common in the English language: To fasten something?

And then in Scandinavian it means fast= solid / together.

Many words that describe the form of  ice, snow etc. are Norwegian or Swedish, and not Danish the only Danish word to describe a form of ice, I can think of, is Isstrøm, instead of Bræ/  Bre (Norwegian) or Gletscher (German).

Even the word Slalom is Norwegian and mean the opposite of downhill.
Title: Re: Stupid Questions :o
Post by: Espen on April 25, 2014, 09:43:27 PM
Some more words comes to mind:
Rucksack= Norwegian
Smorgasbord= Swedish
Beck= Scandinavian
Ski=Norwegian
Dublin= Black River / Pool (Vikings)
Title: Re: Stupid Questions :o
Post by: Anne on April 25, 2014, 09:48:39 PM
Indeed, and you'd say "hold fast to that notion."

Lots of loan words here from Scandinavian languages. Berserk, maelstrom, ransack... Few English speakers seem to know their origin.
Title: Re: Stupid Questions :o
Post by: Espen on April 25, 2014, 10:13:02 PM
Indeed, and you'd say "hold fast to that notion."

Lots of loan words here from Scandinavian languages. Berserk, maelstrom, ransack... Few English speakers seem to know their origin.
That said Scandinavian is basically German!
Title: Re: Stupid Questions :o
Post by: theoldinsane on April 25, 2014, 10:59:56 PM
BTW

Iceberg

What about the "berg"? Well, in Swedish and Norwegian a berg is a rock or mountain. But in Danish it is bjerg. Maybe to difficult to pronounce in English I suppose.
Title: Re: Stupid Questions :o
Post by: Espen on April 25, 2014, 11:15:30 PM
And in German gebirge, and in in Danish a real berg don't exist, the maximum height in Denmark is +/- 180 meters.
Title: Re: Stupid Questions :o
Post by: icefest on April 25, 2014, 11:18:53 PM
Sea ice forums, where a question about sea ice is turned into an etymological debate...

I'd like to point out that in this case fast came via germanic from the proto indo european "past".
Title: Re: Stupid Questions :o
Post by: seattlerocks on April 26, 2014, 01:03:16 AM
Thanks to Icefest, and to all of you for the  linguistic discussion, I did not know about the sort of opposite meanings of "fast". Despite my nickname, English is not my native language so I appreciate it.
Title: Re: Stupid Questions :o
Post by: ChasingIce on April 26, 2014, 06:10:46 AM
If you had to pick an oceanic pattern, which oceanic region would you pick to predict the future of the globe?
Title: Re: Stupid Questions :o
Post by: Pmt111500 on April 26, 2014, 08:49:45 AM
If you had to pick an oceanic pattern, which oceanic region would you pick to predict the future of the globe?
My answer (there are couple others that are relevant too, imo, like the amount of deeper water exchange between North and South Pacific see f.e. http://link.springer.com/article/10.1007%2Fs00382-014-2147-z (http://link.springer.com/article/10.1007%2Fs00382-014-2147-z) ), would be this one :
some recent papers:
http://www.brest.ird.fr/personnel/ppenven/publications/beal_nature2011.pdf (http://www.brest.ird.fr/personnel/ppenven/publications/beal_nature2011.pdf)
http://www.ocean-sci.net/9/773/2013/os-9-773-2013.pdf (http://www.ocean-sci.net/9/773/2013/os-9-773-2013.pdf)
http://www.researchgate.net/publication/256495054_Agulhas_salt-leakage_oscillations_during_abrupt_climate_changes_of_the_Late_Pleistocene/file/3deec5231b5e4f0575.pdf (http://www.researchgate.net/publication/256495054_Agulhas_salt-leakage_oscillations_during_abrupt_climate_changes_of_the_Late_Pleistocene/file/3deec5231b5e4f0575.pdf)
enlarged table on paleorecord here showing there's correlation with abrupt events in climate history and Agulhas Leakage. Whether Agulhas Leak amounts are leading the abrupt changes or come closely after them I can't say but clearly there's a connection.
http://www.nature.com/nature/journal/v472/n7344/fig_tab/nature09983_F4.html (http://www.nature.com/nature/journal/v472/n7344/fig_tab/nature09983_F4.html)
Title: Re: Stupid Questions :o
Post by: E. on May 07, 2014, 02:12:55 AM
Can anyone explain to me the CVFS2 data that show no August anomaly in Arctic sea ice?  Joe Bastardi is trumpeting it on WUWT as the beginning of the end of sea ice decline.  What is the model seeing that the experts here are not, and that is causing this result?

Also as to the "fast" discussion: there is a beautiful short chapter of Moby Dick called "Fast Fish and Loose Fish" that discusses the 19th Century legal test for determining who owns the whale you just speared if there is already someone else's spear in it.  It's fascinating.
Title: Re: Stupid Questions :o
Post by: Csnavywx on May 07, 2014, 12:25:28 PM
Can anyone explain to me the CVFS2 data that show no August anomaly in Arctic sea ice?  Joe Bastardi is trumpeting it on WUWT as the beginning of the end of sea ice decline.  What is the model seeing that the experts here are not, and that is causing this result?

Also as to the "fast" discussion: there is a beautiful short chapter of Moby Dick called "Fast Fish and Loose Fish" that discusses the 19th Century legal test for determining who owns the whale you just speared if there is already someone else's spear in it.  It's fascinating.

The CFS is notoriously bad at sea ice prediction. Bastardi is trumpeting it because that's about all he has left.
Title: Re: Stupid Questions :o
Post by: Neven on May 07, 2014, 01:48:14 PM
Can anyone explain to me the CVFS2 data that show no August anomaly in Arctic sea ice?  Joe Bastardi is trumpeting it on WUWT as the beginning of the end of sea ice decline.  What is the model seeing that the experts here are not, and that is causing this result?

Also check comments by Nick Stokes and Steve Mosher below the WUWT article.
Title: 2M temp + dewpoint?
Post by: epiphyte on May 14, 2014, 08:41:23 PM
Hi all,

Neven recently posted a current DMI 2m temp SAT map showing pretty much uniform 0 degrees C temp everywhere there is ice...

https://lh3.googleusercontent.com/-0XYWv18zjlw/U3MRGwvYs_I/AAAAAAAABrw/16BKP3giTjY/s446/temp_latest.big.png

...Am I correct in assuming that an air temp of 0C right above ice can be an indication that the humidity is high enough for moisture to be condensing on the ice, thereby warming it?

...could it even be the case that when the air temp is _above_ 0C a short distance above ice, it might be because the humidity is too low to permit much heat to be transferred between the two?

If there's any truth to either or both of the above, would a uniform 0 degree temp across the whole arctic simply be an indication that there is sufficient surface insolation to raise the temperature to the point where where the ice is getting warmer, and the air is being cooled by either melting ice, or condensation onto sub-zero ice?

If dewpoint is as significant as it would seem to be in this situation, is there any direct or indirect way of knowing what it is at any given point using the available observations, etc?



Title: Re: Stupid Questions :o
Post by: LRC1962 on May 21, 2014, 06:04:42 AM
From CBC blog:
Quote
Blustery Weather In The High Arctic...
By Christy Climenhaga on May 15, 2014 2:12 PM

    A wind warning is now in effect for Grise Fiord NU. Winds have been gusting to 110 km/h today and will remain strong until this evening.
    Along with the windy weather, snowfall is present in the area, causing blowing snow and near blizzard conditions.
    Windy weather and snow is also in the Kitikmeot region of Nunavut, which is expected to continue tomorrow.
    Cloudy weather is in the forecast for the Kivalliq region, with light wet flurries in Baker Lake.
    Temperatures in the area will remain just above freezing.
    After snowfall last night in Iqaluit, things should remain dry for the day tomorrow.
    Further north on Baffin Island, things will remain overcast and flurries are in the forecast.


NWT OUTLOOK

    Light rain/snow will remain for the Mackenzie Delta tomorrow, with temperatures rising to 4 degrees.
    Rain showers are also expected in the Sahtu tomorrow while the south will remain clear.
    Along with the clear weather, the south will see warm temperatures in the teens or near 20 degrees in the Dehcho.


YUKON OUTLOOK

    Stray cloud cover is expected through most of the Yukon tomorrow with showers in the forecast for Old Crow.
    Temperatures will be warm in the territory, in the high teens in the south, and near 20 degrees in Dawson City.
According to this 2 things were happening that day Very high winds wet snow (at least in the Baffin Island area. I am no ice expert, but I would not think either of those conditions would be healthy for ice, and you got both.
Title: Re: Stupid Questions :o
Post by: LRC1962 on May 21, 2014, 07:20:01 AM
A question: How can you have relative humidity of over 100%?
Googling that added more to my confusion as I got everything from max of 100% to yes in a supersaturation case which can only last a very short time to - depending on if you are above or below freezing on land or over ice depends open how you take the measurements and what formula you use.
Liverpool Bay, Northwest Territories, Canada

Quote
latitude: 69-36N, longitude: 130-54W, elevation: 102 m

METAR: CWLI 210500Z AUTO 03016KT M06/ A3012 RMK SLP212
Time: 23:44 (05:44 UTC)
Current weather observation
The report was made 44 minutes ago, at 05:00 UTC 
Wind 16 kt from north/northeast
Temperature -6°C
Humidity 157%
Pressure 1020 hPa
Visibility
Title: Re: Stupid Questions :o
Post by: LRC1962 on May 21, 2014, 07:52:07 AM
Probably asked and answered a hundred times already: How do you post images on this forum?
I do understand it must be from somewhere online. I do think it must end with the right type of file. So with all the security storage share sites have now, which sites are the easiest to upload to that you then can share on this forum?
Title: Re: Stupid Questions :o
Post by: icefest on May 21, 2014, 08:53:18 AM
You can upload via attachments directly to this website:

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fpuu.sh%2F8UUkv.png&hash=e0ef290f7d870133a56038331be40789)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fpuu.sh%2F8UUl0.png&hash=d11006f8f8f36ebccd8908080ac42b1b)


I personally prefer www.puu.sh  (http://www.puu.sh)
You install an app on your pc and then you can press <Ctrl + 4> and draw a box on your screen.
The program then uploads the images and puts the URL in your clipboard so you can just paste it in here like this:
Code: [Select]
[img]http://puu.sh/8UUri.png[/img]
-icefest
Title: Re: Stupid Questions :o
Post by: crash on May 21, 2014, 07:58:05 PM
I have a stupid question.  Can one think of "cold" (or maybe "cold air") as an entity that is conserved? E.g., if the U.S. Midwest is having an extra-cold winter, does that mean we have "more" cold air than usual, and so some other place has LESS cold air than usual, because the total amount of cold air remains roughly constant?  Is this why Siberia had a warmer winter this past year?

Or could every place  in the world have "more" cold air than normal (here I am assuming no volcanic activity, etc.)?

(I guess with the understanding that the total "mass" of cold air is decreasing from year to year due to AGW?)

Thanks
Title: Re: Stupid Questions :o
Post by: Rubikscube on May 21, 2014, 10:09:04 PM
I have a stupid question.  Can one think of "cold" (or maybe "cold air") as an entity that is conserved? E.g., if the U.S. Midwest is having an extra-cold winter, does that mean we have "more" cold air than usual, and so some other place has LESS cold air than usual, because the total amount of cold air remains roughly constant?  Is this why Siberia had a warmer winter this past year?

Or could every place  in the world have "more" cold air than normal (here I am assuming no volcanic activity, etc.)?

(I guess with the understanding that the total "mass" of cold air is decreasing from year to year due to AGW?)

Thanks

In some way you are right, however, in physics one never speaks of the amount of cold in a system, one rather speak of the amount of thermal energy in a system. Cold usually refers to a lack of this thermal energy, or alternatively a lack of energy transfer between to systems (a process generally known as heating). So if the US Midwest has an extra cold winter, it means that there is less thermal energy in the Midwest, usually because less energy than usual has been transfered to the Midwest from elsewhere.

Global warming is really about energy accumulating in the Earths oceans and lower atmosphere because GHGs prevent the Earth from radiating as much energy into space as it absorbes from the sun, which is needed to keep the temperature stable.
Title: Re: Stupid Questions :o
Post by: ktonine on May 22, 2014, 02:02:35 AM
I have a stupid question.  Can one think of "cold" (or maybe "cold air") as an entity that is conserved?

(I guess with the understanding that the total "mass" of cold air is decreasing from year to year due to AGW?)

Thanks

Crash - you basically answered (correctly) your own question :)

But, as Rubikscube points out, in a sense while there is no 'conservation of temperature'  if one part of the globe is experiencing significantly cold temperatures there is a good chance another  part is significantly warm and vice versa.  After all, the global mean is not changing much - usually a few hundredths of a degree per month.  Likewise the same can be assumed for precipitation.  Unfortunately, GW predicts that these extremes will become more commonplace.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on May 22, 2014, 12:12:03 PM
my, not trained in physics, answer would be something like: in a sense the universe pool of cold that is the afterglow of big bang is the most conserved entity in the history of the universe. The increase of entropy over time takes care of that. Looking closer, only troposphere, one might argue that there are pools of heat and cold which both try to approach the grey-body temperature of TOA. in a sense they are also conserved wrt equilibrium surface temperature of the planet (heat flow at equilibrium will be such and such in tropics and in the poles). Someone better at physics may see something to correct here.
Title: Re: Stupid Questions :o
Post by: crash on May 22, 2014, 08:59:29 PM
Thanks all, this was helpful. 
Title: Re: Stupid Questions :o
Post by: LRC1962 on May 26, 2014, 03:56:48 AM
Based on what I have picked up watching educational programs only. heat always wants to go to cold. Much like water action in regards to osmosis. Weather systems are what keeps cold and heat separate, or mixes them up, that all depends upon what the weather system is doing at the time.
In regards to heat, we do know approximately how much energy/heat is around on/in the earth over a specific period of time. Therefor if we know that energy level on earth are going up and we have an unusual cold spot, then we know somewhere else there is more heat. That is the tricky thing. For example the average world wide temps have been more or less stable over the last 10 yrs or so. We also know that energy levels (radiation coming in over radiation leaving) have been rising over the same period of time. That means somewhere that heat is rising temperatures where we normally do not record. Best guess is deep ocean. that effects ocean currents and when it does eventually come to the surface again the ocean temps will start rising fast and that will then cause air temps to rise.
As the Arctic is concerned it has the nick name among some as the AC unit of the world. Once the ice is gone that AC unit is broken. Do I need to go farther?
Title: Re: Stupid Questions :o
Post by: Pmt111500 on May 26, 2014, 06:47:15 AM
As the Arctic is concerned it has the nick name among some as the AC unit of the world. Once the ice is gone that AC unit is broken. Do I need to go farther?

Well, Arctic is 'the AC unit of northern hemisphere', if you want to be more scientific about it.

It's not yet totally broken, though, works at reduced capacity. This is such a nice analogy that some numbers might be easily calculated.:
As there's ice also in Greenland (c. 1,7 Mkm2) you could state that the AC unit of northern hemisphere has lost (1-10,7/12,2Mkm2) = c. 12,5% of it's power in 30 years (from yearly means of CT SIA) or that the cooling capacity of the AC unit varies at (estimates) 95%(winter) - 65% (summer) of nominal (100%) value of 1980. once the sea ice is gone this unit works at 10% of nominal level (only Greenland Ice Sheet left, which is getting darker by the years.). I don't know where we could buy a new unit. My hunch is that this reduced power of arctic AC unit is one if not the main reason for wider weather fluctuations in NH projected by the climate models, but I've not seen studies done where this would have been spelled out clearly. It's possible that this is such a basic conclusion that no one has seen the trouble of getting it through the peer-review system.
Title: Re: Stupid Questions :o
Post by: misfratz on May 29, 2014, 02:25:17 PM
A question: How can you have relative humidity of over 100%?
Googling that added more to my confusion as I got everything from max of 100% to yes in a supersaturation case which can only last a very short time to - depending on if you are above or below freezing on land or over ice depends open how you take the measurements and what formula you use.
Liverpool Bay, Northwest Territories, Canada

Quote
latitude: 69-36N, longitude: 130-54W, elevation: 102 m

METAR: CWLI 210500Z AUTO 03016KT M06/ A3012 RMK SLP212
Time: 23:44 (05:44 UTC)
Current weather observation
The report was made 44 minutes ago, at 05:00 UTC 
Wind 16 kt from north/northeast
Temperature -6°C
Humidity 157%
Pressure 1020 hPa
Visibility
It is worth remembering that the saturation humidity with respect to ice is different than that compared to water.

Thus you can have a situation which is super-saturated with respect to ice and undersaturated with respect to water, so that, for example, water droplets will evaporate and water vapour will deposit onto ice crystals. This is important in cloud microphysics and produces effects such as riming.

Given that you have a temperature at the station of below freezing, my guess would be that it is giving you the relative humidity with respect to ice, but that there is a humidity source from liquid water that is keeping the humidity higher than would otherwise be possible.
Title: Re: Stupid Questions :o
Post by: k largo on May 30, 2014, 06:29:39 PM
A question: How can you have relative humidity of over 100%?
Googling that added more to my confusion as I got everything from max of 100% to yes in a supersaturation case which can only last a very short time to - depending on if you are above or below freezing on land or over ice depends open how you take the measurements and what formula you use.
Liverpool Bay, Northwest Territories, Canada

Quote
latitude: 69-36N, longitude: 130-54W, elevation: 102 m

METAR: CWLI 210500Z AUTO 03016KT M06/ A3012 RMK SLP212
Time: 23:44 (05:44 UTC)
Current weather observation
The report was made 44 minutes ago, at 05:00 UTC 
Wind 16 kt from north/northeast
Temperature -6°C
Humidity 157%
Pressure 1020 hPa
Visibility

It is a good question, but the answer is quite  simple.

The METAR you quote has no Dew Point Temperature (DP). The Temperature is given as -6/  and there is a space where the DP would be.
The program which decoded the METAR has read the blank space as zero and therefore gives a nonsense value.
By definition Relative Humidity cannot be over 100% except as you mention in isolated cases of super saturation.  Even over ice the RH cannot be over 100%, but it is true that the saturation vapour pressure associated with ice (usually in clouds) can be different than with air. That doesn’t change the fact that RH can’t be greater than 100%, it just means as you also wrote, the way of calculating it is different. If the subzero temperature of the ice is not taken into account then values of over 100% are given but in fact the calculation should be done differently so that the value will be 100% or lower. See: http://www.mbw.ch/papers/RH_WMO.pdf (http://www.mbw.ch/papers/RH_WMO.pdf)

In regard to Liverpool Bay and other stations, there may not be a humidity sensor and therefore the reading is blank. Remarkably many web sites giving those observations take that as zero.

See the 24 hour trend  for CWLI here: http://www.checkwx.com/weather/CWLI (http://www.checkwx.com/weather/CWLI)
The Dewpoint temperature is reported as an unchanged 32F all day.
Title: Re: Stupid Questions :o
Post by: Theta on June 04, 2014, 11:55:55 AM
Since there is a chance of the East Siberian Shelf being devoid of ice this year, what are the implications for Methane release in this regard. Are we likely to see releases that echo the worst case Climate Change scenarios?
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on June 04, 2014, 12:09:24 PM
We have a comedy quiz in the UK known as QI (Quite interesting) and , on occasion, we have a 'nobody knows!' answer and I think this falls into that category Theta?

After the international study in 2011(?) that brought us the info that the 'chimney' features had grown ten fold from the previous year I have come across very little in the way of papers/data?

I cannot believe that an international team , spurred on by ships capt.s reporting 'boiling oceans', back in 2011 just abandon their studies?

Maybe in this climate of climate disinformation they are making sure that they have all the data ( esp. if bad news) checked and correctly interpreted before we get a release?

Such early open water must have impact on water column temps though?
Title: Re: Stupid Questions :o
Post by: Theta on June 04, 2014, 12:39:58 PM
We have a comedy quiz in the UK known as QI (Quite interesting) and , on occasion, we have a 'nobody knows!' answer and I think this falls into that category Theta?

After the international study in 2011(?) that brought us the info that the 'chimney' features had grown ten fold from the previous year I have come across very little in the way of papers/data?

I cannot believe that an international team , spurred on by ships capt.s reporting 'boiling oceans', back in 2011 just abandon their studies?

Maybe in this climate of climate disinformation they are making sure that they have all the data ( esp. if bad news) checked and correctly interpreted before we get a release?

Such early open water must have impact on water column temps though?

Thanks Gray, the fact that nobody knows makes me glad I put my question in this thread rather than derailing everyone's observation of the ongoing Sea Ice Melt.

Overall, it is also quite frightening that we don't even have to lose much ice in order for the clathrate gun to fire right into the heart of earth's ecosystem.
Title: Re: Stupid Questions :o
Post by: JayW on June 04, 2014, 12:53:28 PM
Sorry if this has been discussed, but I had a couple questions/thoughts.

This is only my second ice watching season, so it's impossible for me to compare to others years.  However, I have seen others comment on the poor state of the ice, wether it be fractured, or slushy, or rotten.  My question is, if the ice is becoming more "porous", wouldn't that make it more difficult for melt ponds to form? 

My second is more of a thought.  Where I live, lakes and ponds freeze for 3-5 months of the year, with thickness that can reach 1 meter in the more northern areas.  I have done a fair amount of ice fishing, and with lakes all around me, have watched "ice out" on many occasions.  I'm not sure how much of what I observe when freshwater lakes melt can be applied to arctic ice melt, but one thing sucks in my mind.  It has to do with wind, and it's effects on the difference between temperature at 2 meters and the air that "hugs" the ice.  When standing on the ice on a relatively warm day without any wind, your feet can get quite cold because of the cold that seems to suck right on the ice.  Yet, on cooler days with wind, your feet wouldn't feel as cold because that frigid cold that seems to radiate to your feet is scoured away.
Hope I worded that right.

My point is that wind is extremely important in the melting process of our lakes.  Coupled with elevated dew points,  the wind can really eat ice, even at temps just above freezing.  Also, one would be surprise how much "grip" smooth ice can get on the wind.  I have seen light, but persistent breezes pushing the ice around surprisingly easily once it begins to melt away from shore. 

Like I sad though, perhaps this has no qualitative value in regards to arctic ice.  :)

Edit: oops thought I was in the drift, deformation, and fracture thread.  It's probably a stupid question any way.  :P
Title: Re: Stupid Questions :o
Post by: DoomInTheUK on June 05, 2014, 01:46:16 PM
Jay,

Not really a stupid question, more one of scale of view.

Yes the ice can have changes in it's surface, rippling, snow cover, be more porous etc. This will have localised impacts for the ice's strength, how well melt-ponds form and how long they will last.

Porous ice is weak ice and will break more easily, but that still may leave chunks 100's or 1000's meters across. Each one is large enough to hold multiple melt ponds. The porous ice below a melt pond will allow it to drain quicker by opening a hole through, and so this warm water gets a quicker path through to the underside.

Stress, melt ponding and surface changes can't be taken in isolation nor can they be viewed with a given timeline. Each attribute effects the other. Ice behaves more like a slow fluid than a flexible solid.
Title: Re: Stupid Questions :o
Post by: crash on June 09, 2014, 06:19:10 PM
I have a stupid question.  When you go to the DMI Centre for Ocean Ice, and look at the historical "Daily Mean Temperatures for 80N":

http://ocean.dmi.dk/arctic/meant80n.uk.php (http://ocean.dmi.dk/arctic/meant80n.uk.php)

The winters seem to be a lot more "spiky", i.e. departures from the mean are often 10 degrees K +/-.  However during the summer, departures from the mean are much smaller.  Why is this? 

I suppose I can guess that even during the summer, temps don't get much above freezing because, well, there's mostly just ice at 80N and "above", even with the ice coverage trending downward. 

Still,  the  area N of 80N is not covered in ice during June and July (right?), so I would expect some spikes up to maybe 280 Kelvin here and there.  Is the reason that water is most of what's N of 80N, and the water is going to stay a few degrees above freezing, and therefore limits the temps to around 275K for the most part? 
Title: Re: Stupid Questions :o
Post by: crandles on June 09, 2014, 07:28:32 PM
It is June now and it is almost all ice covered with maybe a couple of tiny exceptions. Even at the minimum in September I would suggest at least 70% of area remains ice covered (including melt ponds) with temp close to 0C. Most of the remaining water will have ice pretty close so that water doesn't get much above melting point -1.5C. That will only leave about 10% of the area where the water can warm to 2 or 3C. So surface temperature has probably remained negative so far. 2m and above can be warmer due to winds from warmer more southerly locations.

Summer temperatures are declining slightly if you flick through quite a few years. Probably due to larger areas near -1.5C for melting point of sea water rather than 0C for a melt pond of low salinity water.

Temps in winter can vary a lot as winds can circulate around pole and get very cold or warm winds can bring in some heat from a warmer direction (Atlantic or Pacific).

In summer the latent heat required to melt ice keeps the surface near 0 or -1.5 and that soon cools surface winds.
Title: Re: Stupid Questions :o
Post by: Andreas T on June 15, 2014, 08:10:20 PM
another effect which contributes to those rapid changes in winter is that the lowest temperatures occur when clear skies allow surfaces to cool by radiating heat out into space. This means a very thin surface layer is affected by the cooling. The surface is often covered in snow, which as a good insulation has a steep temperature gradient, much of its depth cools much more slowly than the surface. Air which is cooled by the surface stays in contact with the surface because it increases its density so relatively small volumes (and heat capacities) of snow and air are affected by cooling so temperature drops are rapid. When conditions change, either by advection of warmer air or by clouds reducing the cooling these relatively thin layers of air and snow warm up quite quickly.
One place where this can be observed is in the temperature profiles measured by buoys where temperatures drop at the surface well below those of the bulk of the ice only to return soon to something close to the ice temperature.
Title: Re: Stupid Questions :o
Post by: Anne on June 19, 2014, 05:04:00 AM
This is a REALLY stupid question. It deserves to get me expelled.
Elsewhere on the forum there is a fair bit of cognitive dissonance over the stories told by NSDIC and so on compared with weather reports. There aren't enough buoys out there and it's mostly too cloudy to have a clear satellite view. So how can we know what's really going on? Or can we?
And of course we can't really know, but how to decide the deductions are good enough?
Title: Re: Stupid Questions :o
Post by: jdallen on June 19, 2014, 10:03:07 AM
This is a REALLY stupid question. It deserves to get me expelled.
Elsewhere on the forum there is a fair bit of cognitive dissonance over the stories told by NSDIC and so on compared with weather reports. There aren't enough buoys out there and it's mostly too cloudy to have a clear satellite view. So how can we know what's really going on? Or can we?
And of course we can't really know, but how to decide the deductions are good enough?
There's a lot that can be gleaned by via satellite looking at the height of the atmosphere, and how it responds/reflects various wavelengths of EMR, from visible down.  It doesn't depend on visible light.

There's a lot which can be interpolated between buoys, so even though they are sparse, a lot can be gathered from them.

So on a broad scale, we know a lot about what is going on in the arctic.  That understanding also applies to longer time scales, as we can read the history of the weather in climate and seasonal changes.

Our understanding becomes somewhat fuzzier as we move to shorter time spans, and areas outside of those immediately in the vicinity of sensors, or which do not lend themselves to easy interrogation by sensors examining specific frequencies of light or radio waves.
Title: Re: Stupid Questions :o
Post by: Jim Hunt on June 19, 2014, 10:07:00 AM
And of course we can't really know, but how to decide the deductions are good enough?

That's not a stupid question at all, and certainly not one that should result in expulsion!

What counts as "good enough"? Surely any information is better than none? Some frequencies "see" through clouds better than others, but unfortunately none of them seem terribly good at working out the thickness of the ice, especially at this time of year.
Title: Re: Stupid Questions :o
Post by: SCYetti on June 20, 2014, 04:09:10 PM
What is the immediate ghg equivalency of methane? I understand using the 20 or 100 year equivalency when reporting the release of a particular mass of methane such as 50 gt. I don't understand using a 20 or 100 year equivalency when reporting parts per billion. If methane in the atmosphere is 1865 ppb its ghg effect will only decrease if its parts per billion decreases. It makes more sense to me to report the 100 year effect when discussing a mass or volume of menthane but use the immediate effect when discussing fractions of the atmosphere.
Title: Re: Stupid Questions :o
Post by: SteveMDFP on June 20, 2014, 07:27:50 PM
What is the immediate ghg equivalency of methane? I understand using the 20 or 100 year equivalency when reporting the release of a particular mass of methane such as 50 gt. I don't understand using a 20 or 100 year equivalency when reporting parts per billion. If methane in the atmosphere is 1865 ppb its ghg effect will only decrease if its parts per billion decreases. It makes more sense to me to report the 100 year effect when discussing a mass or volume of menthane but use the immediate effect when discussing fractions of the atmosphere.
I concur.  I think reporting on methane effects has been flawed, and flawed in a direction that understates the importance and effect of stable (or rising) methane levels.
Title: Re: Stupid Questions :o
Post by: Laurent on June 21, 2014, 11:10:14 AM
Can't find the info on official site but I have heard that methane is 100 times more powerful than CO2 once immediately release and N20 300 time...To me what does matter is that direct effect not the statistical calculation based on natural decrease over time. Of course keep in mind that N2O is a thousand time less concentrated.
If someone could send as a link to official research...thanks in advance.
Title: Re: Stupid Questions :o
Post by: Siffy on June 21, 2014, 01:04:55 PM
I've a bit of a stupid question if any one can humour me.

Is there a study or any material which discusses the effect that fog has on thermal transfer mechanisms such as convection and that describes the difference of fog vs normal air at transferring heat to ice.

My casual understanding is that fog for a given temperature will transfer more heat to the ice than clear air with little relative humidity.
Title: Re: Stupid Questions :o
Post by: Yuha on June 21, 2014, 02:31:04 PM
What is the immediate ghg equivalency of methane? I understand using the 20 or 100 year equivalency when reporting the release of a particular mass of methane such as 50 gt. I don't understand using a 20 or 100 year equivalency when reporting parts per billion. If methane in the atmosphere is 1865 ppb its ghg effect will only decrease if its parts per billion decreases. It makes more sense to me to report the 100 year effect when discussing a mass or volume of menthane but use the immediate effect when discussing fractions of the atmosphere.

A nice source of information on greenhouse gasses is the NOAA Annual Greenhouse Gas Index (AGGI) (http://www.esrl.noaa.gov/gmd/aggi/aggi.html).

Based on the formulas there, the radiative forcing of methane at current levels is about 0.36 W/m2/ppm. For example, if the methane levels increase by 100 ppb, the radiative forcing increases by about 0.036 W/m2. For CO2 the number is about 0.014 W/m2/ppm, which makes methane about 25 times stronger greenhouse gas in this sense.

Often the comparison is made in terms of mass instead of concentration. The molecular mass of CO2 is about 2.75 times the molecular mass of methane, which makes methane about 70 times stronger greenhouse gas in terms of mass.

These numbers are not constant but change with the atmospheric concentrations. When concentrations go up both forcing factors go down but the CO2 factor goes down faster and thus the methane/CO2 ratio tends to increase.


Title: Re: Stupid Questions :o
Post by: wili on June 27, 2014, 02:25:24 PM
Quote
The GWP for methane was increased, from 25 to 28 over a 100-year timespan and from 72 to 84 over a 20-year timespan.  When carbon-climate feedbacks are taken into account, the 100-year GWP of methane increases to a punishing 34 times that of carbon dioxide.  Methane is a growing source of emissions in many countries including the United States due to increased use of natural gas for energy.

http://www.enn.com/press_releases/4210 (http://www.enn.com/press_releases/4210)

But then there's the Schindell paper:

Shindell et al., “Improved Attribution of Climate Forcing to Emissions“,
http://www.sciencemag.org/cgi/content/abstract/326/5953/716 (http://www.sciencemag.org/cgi/content/abstract/326/5953/716)

Quote
This paper argues that methane is more potent than previously realised due to the interaction with black carbon. The paper gives a revised Global Warming Potential for methane measured over 100 years as 33. This is an increase of over 30% compared to the value of 21 given in the IPCC Second Assessment Report used for the Kyoto Protocol.

Over 20 years, Shindell et al. calculate this GWP to be 105.


....
I have my own stupid question, though. (As usual, my apologies if this has been addressed and I missed it.):

It is my understanding that acidic water melts at a lower temperature than non-acidic water. The ocean has famously become more acidic. Is that a significant factor in increased melt from ocean water, both of regular sea ice and of ice shelves we've been hearing so much about recently?

Thanks ahead of time, and apologies if this is over-the-top boneheaded.
Title: Re: Stupid Questions :o
Post by: Anne on June 27, 2014, 07:45:03 PM
Thank you, Jim and jda for replies to my previous Stupid.*  Here's a new one:

People talk about the weather as though it were the ultimate factor affecting ice melt. What about currents and bottom melt? Where is the heat going from Siberia and western Alaska? What has happened to the Fram Strait export, and why? How are Arctic currents changing? Woods Hole seems to have precious little about what's changing.
http://www.whoi.edu/main/topic/currents--gyres-eddies (http://www.whoi.edu/main/topic/currents--gyres-eddies)
How are current currents being monitored?

PS: Wili has a question just above this post and I'm v interested in the answer to that too.

*(Re how good are the data, I guess a better question would have been to ask what sort of confidence intervals attend the various models but I can find that out by looking them up. I was just getting the sense of disagreement between what the heat input seems to be suggesting and the CT etc measurements. I see NSIDC works to 95%.)
http://nsidc.org/data/docs/noaa/g02135_seaice_index/ (http://nsidc.org/data/docs/noaa/g02135_seaice_index/)   
Title: Re: Stupid Questions :o
Post by: johnm33 on June 27, 2014, 08:23:41 PM
Hi Anne, Fram export, open this http://earth.nullschool.net/#current/wind/surface/level/orthographic=-56.26,85.26,512 (http://earth.nullschool.net/#current/wind/surface/level/orthographic=-56.26,85.26,512) click on Earth, go down to control and click the left << [-1 day] shows winds blowing up through Fram for 5 days
Title: Re: Stupid Questions :o
Post by: Anne on June 27, 2014, 08:28:17 PM
Thanks, John! But why had it stalled for so long? I think when we look at the atmosphere alone we are looking at barely half the story.
Title: Re: Stupid Questions :o
Post by: SteveMDFP on June 27, 2014, 08:43:03 PM
Thanks, John! But why had it stalled for so long? I think when we look at the atmosphere alone we are looking at barely half the story.
At some point in following this forum (or the blog), there was a link to an article about Fram export.  That paper, if memory serves, described Fram export as being highly seasonal.  Sluggish transport during the summer is normal; most transport is during the winter. 
If memory serves, we had reasonable brisk transport during the past spring, possibly above average.  I think the 20013 season had sluggish transport from late winter through the summer.

This year, *some* degree of significant transport happened not through the Fram, but through the other side of Svalbard, the not-named-Olga Strait. 

Actually following this mechanism of ice export out of the arctic seems, for most of us, to consist of looking at wind fields.  I understand, however, that PIOMAS models Fram export.
Title: Re: Stupid Questions :o
Post by: LRC1962 on June 27, 2014, 10:08:43 PM
@Anne The reason there is a lot of talk about weather is many fold. Easily noticed, described, somewhat forecastable  and has more immediate impact. There are many other influences, some we are only now discovering quantifiably, but they tend to be still in the study stage, more expensive to conduct those studies and I feel partly because they can be depended upon so many other variables hard to nail down exactly how much and where that impact will be felt most. 1 of those are ocean currents. They do all have big impacts on the ice, its just very hard to know exactly how much, what kind and where it will hit.
With weather, its a far easier job. You have x weather hitting this area you can guess pretty closely you will have Y happening to the ice. The rest ... well if you had about 20 times as many working buoys we could get a far better picture.
Title: Re: Stupid Questions :o
Post by: Bruce Steele on June 27, 2014, 10:30:52 PM
Wili, 
"It is my understanding that acidic water melts at a lower temperature than non-acidic water. The ocean has famously become more acidic. Is that a significant factor in increased melt from ocean water, both of regular sea ice and of ice shelves we've been hearing so much about recently?"

That's a good one. I really don't know about pH and freezing point of water but the science fair experiment I found on google makes it look like you might be on to something. My question would be whether you would have the same effect by bubbling Co2 to change water pH as you get by dissolving a solid like citric acid?

 https://www.usc.edu/CSSF/History/2004/Projects/J0509.pdf (https://www.usc.edu/CSSF/History/2004/Projects/J0509.pdf)
Title: Re: Stupid Questions :o
Post by: wili on June 27, 2014, 11:08:09 PM
Yeah, I saw that science fair project too. The take away, which I'm pretty sure is generally right, is that pretty much anything that mixes with pure water makes lowers its melting point.

I'm just not sure how large an effect that would be with CO2 > carbonic acid, especially since we are not starting with pure water.

Also, iirc, though the oceans are indeed becoming more acidic, it is from a slightly basic starting point, so the increased acidity actually moves the water closer to neutral--still bad for various life forms that have evolved in the older pH range, but we certainly aren't talking about battery acid, here.
Title: Re: Stupid Questions :o
Post by: Bruce Steele on June 27, 2014, 11:24:02 PM
Wili, something just doesn't seem right about this premise. I mean does a steam in N.Y. with a 6.2 pH freeze at a different temperature ( at sea level ) than a steam on the west coast with a pH of 7.4 ? So before I make a total fool out of myself I am putting this one on the shelf a while.
Title: Re: Stupid Questions :o
Post by: greatdying2 on June 28, 2014, 05:35:42 AM
http://en.wikipedia.org/wiki/Freezing-point_depression (http://en.wikipedia.org/wiki/Freezing-point_depression)

ΔTF = Kf · b · i

The above says that freezing (/melting) point depression (delta Tf) for stuff dissolved in water is directly proportional to its molar concentration (b) and a constant (Kf) (and i, which I guess is 1 for CO2 dissolved in water: http://en.wikipedia.org/wiki/Carbonic_acid? (http://en.wikipedia.org/wiki/Carbonic_acid?) Anyways, it makes little difference, because...).

The above link suggests that Kf is ~2. However the following link suggest it may be ~3: http://www.wiredchemist.com/chemistry/data/molal-freezing-boiling (http://www.wiredchemist.com/chemistry/data/molal-freezing-boiling) .

But again, it makes little difference, because the difference (due to anthropogenic CO2?) in the concentration of dissolved CO2 seems to be something on the order of ~300 umol/kg, and pH change of say (to be generous) 8.1 to 7.6 (right?) = (10^-8.1) - (10^-7.6) = 8e-9 - 2.5e-8 ~= 2e-9.

http://www.pmel.noaa.gov/pubs/outstand/feel3087/images/fig02.jpg (http://www.pmel.noaa.gov/pubs/outstand/feel3087/images/fig02.jpg)

So like on the order of a billionth of a degree (times 2 or 3) (for increased H+) or at best on the order of a thousandth of a degree (for dissolved CO2).

But OTOH this may be a stupid answer... mainly trying to remember my chemistry. Hope it helps though.
Title: Re: Stupid Questions :o
Post by: ktonine on June 28, 2014, 06:54:14 AM
People talk about the weather as though it were the ultimate factor affecting ice melt. What about currents and bottom melt?

Anne, there have been many papers written on stronger currents and the influx of warmer Pacific waters into the arctic and their affect on the sea ice - for example The role of Pacific water in the dramatic retreat of arctic sea ice in summer 2007 (http://psc.apl.washington.edu/zhang/Pubs/zhang_etal_PW2009.pdf)
Title: Re: Stupid Questions :o
Post by: greatdying2 on June 30, 2014, 04:22:37 AM
Stupid question to follow my stupid answer:

Has anyone modelled what would happen to the weather if (/when) the arctic sea ice buffer is gone? I.e., Just remove the arctic sea ice from the model(s) to see what happens.

The results might be interesting to those experiencing 'heat waves'. Maybe more people would start putting 2+2 together?

Thanks.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on June 30, 2014, 02:54:23 PM
Stupid question to follow my stupid answer:

Has anyone modelled what would happen to the weather if (/when) the arctic sea ice buffer is gone? I.e., Just remove the arctic sea ice from the model(s) to see what happens.

The results might be interesting to those experiencing 'heat waves'. Maybe more people would start putting 2+2 together?

Thanks.

I have to believe that climate modelers are doing this. How else would they arrive at what future climate may look like which they periodically report? I do think they are likely very cautious about what they report because there is a certain degree of uncertainty with any of these models and they do not want to appear alarmist. I would love to be a fly on the wall and watch "what ifs" as they explore various climate scenarios. I bet some of the climate model outputs are terrifying.
Title: Re: Stupid Questions :o
Post by: crandles on June 30, 2014, 03:24:42 PM
Only a couple of studies I know of:

Schröder, D. and W.M. Connolley, 2007: Impact of instantaneous sea ice removal in a coupled general circulation model. Geophys. Res. Lett., 34, L14502, doi:10.1029/2007GL030253

and

Tietsche et al "Recovery mechanisms of Arctic summer sea ice"

These are looking more at what happens to sea ice than weather and the answer is the models quickly go back to level of sea ice they had before in just a couple of years. Therefore I don't think it sensible to look at weather impacts as these will be too much affected by instant removal and too far from normal ice levels for the model. Possibly you could look at weather effects in runs of removal in 2060 that Tietsche did but you probably need a whole lot of runs to identify what becomes more likely in absence of sea ice.

You really need a climateprediction.net to run models many times over to see different frequencies of weather events. I have asked them (CPDN) if their partial attributions of weather events can be sound if they don't attempt attribution to sea ice retreat. Their answer seemed rather 'well it isn't clear that sea ice retreat effects will dominate'.

Shorter version: I doubt the models can be made to run sensibly as you want reliably enough that you could trust the results.


Title: Re: Stupid Questions :o
Post by: seattlerocks on July 14, 2014, 11:03:38 AM
Hi, what are the implications of Nares strait breaking up? Why it seems relevant. I googled a lot but could not find explanation about it. Thx!
Title: Re: Stupid Questions :o
Post by: Jim Hunt on July 14, 2014, 06:35:55 PM
Hi, what are the implications of Nares strait breaking up? Why it seems relevant.

See for example "Large sea ice outflow into the Nares Strait in 2007":

http://onlinelibrary.wiley.com/doi/10.1029/2009GL041872/pdf (http://onlinelibrary.wiley.com/doi/10.1029/2009GL041872/pdf)

Quote
We note that the exported ice (at 4 – 5 m) found north of Nares Strait represent some of the thickest ice in the Arctic Ocean. This thick, old ice occupies the tails of the thickness distribution and takes years with the right conditions to replenish.

Once the Nares Strait breaks up export of that older, thicker ice from the Central Arctic begins.
Title: Re: Stupid Questions :o
Post by: seattlerocks on July 14, 2014, 11:56:18 PM
Thank you  very much, Jim!
Title: Re: Stupid Questions :o
Post by: greatdying2 on July 15, 2014, 07:13:46 AM
Which illustrates how dependent the Arctic is on its peculiar geography. What if, for example, Ellesmere Island didn't exist. Might there be ice-free summers already?
Title: Re: Stupid Questions :o
Post by: greatdying2 on July 15, 2014, 07:30:28 AM
Another stupid question. (Forgive me if it's not directly about ice.) Plots of atmospheric CO2 concentration are a lynchpin of the global warming debate. But what about CH4? Is methane being monitored (it must be?!), and if so, why aren't these plots more focussed on? I know that it has a *much* shorter half-life, but it's also far more potent while it lasts, right? And isn't there (still) concern about catastrophic release, e.g. from frozen methane deposits or from rotting no-longer-perma-frost?

Thanks!
Title: Re: Stupid Questions :o
Post by: trebuh on July 15, 2014, 07:41:22 AM
answer is $
Title: Re: Stupid Questions :o
Post by: greatdying2 on July 15, 2014, 01:03:28 PM
Thanks again. Scary. Given the potential, it boggles the mind there isn't more research being done.
Title: Re: Stupid Questions :o
Post by: wili on July 16, 2014, 06:45:29 AM
My understanding of J. Frances's theory about 'stuck' weather patterns is that it is a consequence of disproportionate warming of the Arctic, including the ever greater melting of sea ice. But wouldn't that only explain north hemisphere phenomena?

But aren't stuck patterns now becoming more common also in the southern hemisphere (for example, what NZ is experiencing now)?

Is the warming of the southern oceans enough to create a similar dynamic there as in the north?

Or is there something else affecting the movement of these systems?

(This is where the really stupid question part comes in...so be nice :-*)

Another thing we know about the basic changes going on in the atmosphere is that there is more water vapor (up by about 6% on average, iirc). Even though there is also more energy in the system, would all that extra water tend to slow down these system--are they just too heavy to move along as fast as they used to?
Title: Re: Stupid Questions :o
Post by: Kethern on July 16, 2014, 07:58:57 PM
My understanding of J. Frances's theory about 'stuck' weather patterns is that it is a consequence of disproportionate warming of the Arctic, including the ever greater melting of sea ice. But wouldn't that only explain north hemisphere phenomena?

But aren't stuck patterns now becoming more common also in the southern hemisphere (for example, what NZ is experiencing now)?

Is the warming of the southern oceans enough to create a similar dynamic there as in the north?

Or is there something else affecting the movement of these systems?

(This is where the really stupid question part comes in...so be nice :-*)

Another thing we know about the basic changes going on in the atmosphere is that there is more water vapor (up by about 6% on average, iirc). Even though there is also more energy in the system, would all that extra water tend to slow down these system--are they just too heavy to move along as fast as they used to?

My first guess would be that it doesn't. The molecular weight of dry air is ~29, the molecular weight of water is 18. Assuming the water vapor displaces an equal amount of dry air than the extra water should be making the atmosphere lighter not heavier. Given the relatively small percentage of water to vapor to the total atmosphere I doubt it has any appreciable effect.
Title: Re: Stupid Questions :o
Post by: helorime on July 16, 2014, 10:31:55 PM
You are neglecting density.  MW does not tell the story.  Air is a gas, water is a liquid.  If the densities were equal our atmosphere would be under the oceans.  Humid air is substantially more dense than dry air.
Title: Re: Stupid Questions :o
Post by: wili on July 16, 2014, 10:42:13 PM
Thanks, helorime.
Title: Re: Stupid Questions :o
Post by: Vergent on July 16, 2014, 10:57:54 PM
Humid air is substantially more dense than dry air.

helorime,

I am afraid you have this backward. Oxygen has a molecular weight of 32 g/mole, nitrogen 28 g/mole. Water vapor has a molecular weight of 18 g/mole. Water vapor and steam are lift gasses.

We often talk of humid air as "heavy", this is a mistaken notion.

Verg



Title: Re: Stupid Questions :o
Post by: SteveMDFP on July 16, 2014, 11:07:50 PM
Humid air is substantially more dense than dry air.

helorime,

I am afraid you have this backward. Oxygen has a molecular weight of 32 g/mole, nitrogen 28 g/mole. Water vapor has a molecular weight of 20 g/mole. Water vapor and steam are lift gasses.

We often talk of humid air as "heavy", this is a mistaken notion.

Verg

For a slightly more academic discussion:
http://antoine.frostburg.edu/chem/senese/101/gases/faq/wet-air-dry-air-density.shtml (http://antoine.frostburg.edu/chem/senese/101/gases/faq/wet-air-dry-air-density.shtml)

At a given temperature and pressure, a container of a given size will have a specific number of gas molecules.  If those molecules are of higher molecular weight, the gas is heavier.  If of a lower molecular weight (e.g., hydrogen, H2, or Helium, for example) the gas can be closer in weight to a vacuum than to atmosphere. 
Humid air may *feel* heavy, but it is actually lighter than dry air.
Title: Re: Stupid Questions :o
Post by: helorime on July 17, 2014, 09:00:09 AM
I stand corrected!  I did not know that.  In my head water in air was like a solute in water, incresing density.  I assumed that the polar nature of water would interact with the gasses in the air in a way not dissimilar to what it does in water, increasing the density with its transient electrical forces.
Title: Re: Stupid Questions :o
Post by: be cause on July 17, 2014, 09:48:02 AM
I suppose if the above were not true rain would have nowhere to fall from ..
Title: Re: Stupid Questions :o
Post by: wili on July 17, 2014, 03:01:56 PM
H, I obviously made the same assumption. :-[
I guess that's why we come here, to learn.
What is the quote about the things we know for sure that just aren't so?
Thanks all.
Title: Re: Stupid Questions :o
Post by: johnm33 on July 17, 2014, 07:58:59 PM
I'm suprised by this too,  does this mean that wherever evaporation is taking place the atmosphere expands at a prodigious rate? and of course with condensation the reverse?
 Plus a supplemental when exactly was sea level so high as to cover the Yamal peninsular?
Title: Re: Stupid Questions :o
Post by: jdallen on July 17, 2014, 08:28:08 PM
I'm suprised by this too,  does this mean that wherever evaporation is taking place the atmosphere expands at a prodigious rate? and of course with condensation the reverse?
 Plus a supplemental when exactly was sea level so high as to cover the Yamal peninsular?
You are mostly correct, and are now describing one of the major driving mechanisms of the great heat engine that is our weather.

In this case, the "steam engine" component ;)
Title: Re: Stupid Questions :o
Post by: Vergent on July 17, 2014, 09:00:36 PM
Plus a supplemental when exactly was sea level so high as to cover the Yamal peninsular?

120 kybp

http://geochemistry.usask.ca/bill/Courses/International%20Field%20Studies/Sea%20level.pdf (http://geochemistry.usask.ca/bill/Courses/International%20Field%20Studies/Sea%20level.pdf)
Title: Re: Stupid Questions :o
Post by: ktonine on July 18, 2014, 03:28:09 AM
"It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so."  Usually attributed to Mark Twain.
Title: Re: Stupid Questions :o
Post by: TerryM on July 18, 2014, 01:22:38 PM
Look to the clouds to see how heavy water vapor is.
Terry
Title: Re: Stupid Questions :o
Post by: crandles on July 18, 2014, 01:50:08 PM
Look to the clouds to see how heavy water vapor is.
Terry

Clouds are not water vapour but small water droplets.

Water vapour is light and tends to rise and the droplets are small so have large surface area to volume so that the droplets tend to get carried up with rising air until the droplets get large enough that their weight overwhelmes the updraft effect and they fall.

However the updraft effect is largely driven by water vapour condensing into droplets releasing latent heat, warming the air which expands to create lower density.

So I don't think you can tell water vapour is light by looking at clouds.
Title: Re: Stupid Questions :o
Post by: johnm33 on July 18, 2014, 03:00:41 PM
So at sea level what volume would 1cc of water occupy as vapour, and how much lighter than 'air' would it be?
Title: Re: Stupid Questions :o
Post by: crandles on July 18, 2014, 04:04:30 PM
Googled density of water vapour to get:
At equivalent temperatures it is buoyant with respect to dry air, whereby the density of dry air at standard temperature and pressure is 1.27 g/l and water vapor at standard temperature and pressure has the much lower density of .804 g/l.

Water, Density 999.97 kg/m³

(news to me I thought it was 1000. g/l is the same as Kg/m^3)

so 1cc of water becomes 1000/0.804 = 1244 cc.
Title: Re: Stupid Questions :o
Post by: TerryM on July 18, 2014, 09:11:35 PM
Thanks Crandles
It's an old saw i learned from a pilot decades ago & it's stuck in my head like a commercial jingle.
I remember the phrase & forget that it's BS, such is the aging process.
Terry
Title: Re: Stupid Questions :o
Post by: jdallen on July 18, 2014, 09:32:41 PM
Googled density of water vapour to get:
At equivalent temperatures it is buoyant with respect to dry air, whereby the density of dry air at standard temperature and pressure is 1.27 g/l and water vapor at standard temperature and pressure has the much lower density of .804 g/l.

Water, Density 999.97 kg/m³

(news to me I thought it was 1000. g/l is the same as Kg/m^3)

so 1cc of water becomes 1000/0.804 = 1244 cc.

Actually, density changes dramatically with temp.  It is most dense at around 4C, paradoxically, because of the structure of the molecule, and how transitory hydrogen bonds are formed.  Check out the water temperature/density graph.

This also helps illustrate why some sea level rise is a direct function of temperature, rather than melt.

http://www.engineeringtoolbox.com/water-density-specific-weight-d_595.html (http://www.engineeringtoolbox.com/water-density-specific-weight-d_595.html)

Title: Re: Stupid Questions :o
Post by: plg on July 18, 2014, 09:34:36 PM
Googled density of water vapour to get:
At equivalent temperatures it is buoyant with respect to dry air, whereby the density of dry air at standard temperature and pressure is 1.27 g/l and water vapor at standard temperature and pressure has the much lower density of .804 g/l.

Water, Density 999.97 kg/m³

(news to me I thought it was 1000. g/l is the same as Kg/m^3)

so 1cc of water becomes 1000/0.804 = 1244 cc.

Water vapor has less density ("lighter" is not an appropriate term), but water vapor and air as not as oil and water, the vapor will not rise and float on top of the air, it will be a homogenous mixture. If you take a container and put in any arbitrary gases, they will be perfectly mixed. Only at extremely low temperatures (close to 0K) will the heavier molecules perhaps drift downwards (I think).

Of course, there are many other factors in the weather system that will affect the gas composition: pressure and temperature gradients, which may cause condensation, as well as other factors I know little about.

Having said all this, I may be completely wrong...
Title: Re: Stupid Questions :o
Post by: crandles on July 19, 2014, 12:12:26 AM
Having said all this, I may be completely wrong...

Pretty sure that people living at sea level don't suffocate in Argon and/or other heavy molecules so I don't think you are completely wrong ;)
Title: Re: Stupid Questions :o
Post by: Andreas T on July 19, 2014, 01:24:36 AM

......
However the updraft effect is largely driven by water vapour condensing into droplets releasing latent heat, warming the air which expands to create lower density.
....
maybe I am stating the obvious but I want to stress that warming is this context is not an increase in temperature. What the condensation does, is it allows the air to rise and expand without (or with less) cooling. The difference between moist adiabatic lapse rate and dry adiabatic lapse rate shows that. Therefore the previously humid air is warmer and less dense than other air at that altitude which gives it its buoyancy.
 Another way to express that is looking at its potential temperature, should this air move to lower altitude its temperature will rise due to the compression but since temperature rise is steeper for the now drier air it will end up at sea level warmer than it started there as humid air.
So in that case there will be a rise in temperature and the increase in potential temperature shows that possibility.
Title: Re: Stupid Questions :o
Post by: greatdying2 on July 21, 2014, 03:54:18 AM
Is extent simply the area that exceeds some arbitrary concentration threshold (e.g. 15%)? If so, is there any natural justification for the threshold, or is it arbitrary? More importantly, if it is just a threshold, then why does anyone care about extent? Shouldn't area be paramount?

(I'm tempted to say volume should be paramount, but since we can't see under water from satellites and have virtually no measurements, it's more likely a pipe dream...)

Taking the idea (that area has more information than extent) one step further, wouldn't it be useful to see area distributions rather than just averages. This is how it is displayed visually, but I haven't seen it tallied up on graphs, which would make for easier qualitative comparisons. Would this not go some way towards addressing the ice quality question?
Title: Re: Stupid Questions :o
Post by: crandles on July 21, 2014, 02:44:25 PM
Is extent simply the area that exceeds some arbitrary concentration threshold (e.g. 15%)? If so, is there any natural justification for the threshold, or is it arbitrary?
Yes.
Also the difference between area and extent depends on resolution.
Some organisation used (still use?) 30% rather than 15% but I think there seems to be a move towards 15%. There may be some justification for using these thresholds - eg above 30% there does not seem any ice free passage though the ice as seen from ship height whereas up to 15% looks like open water with just a few floes.

Quote
More importantly, if it is just a threshold, then why does anyone care about extent? Shouldn't area be paramount?

(I'm tempted to say volume should be paramount, but since we can't see under water from satellites and have virtually no measurements, it's more likely a pipe dream...)

It is fairly similar to the volume situation. Volume would ideally be paramount but we are not very sure of volume particularly if we go back in time.

If you want comparability over more than 50 years of time then extent is much better known than area as information comes from ships observations. Area may seem a better measure but if you have no ships within the ice to observe leads and polyna, then you have to use extent.


Quote
Taking the idea (that area has more information than extent) one step further, wouldn't it be useful to see area distributions rather than just averages. This is how it is displayed visually, but I haven't seen it tallied up on graphs, which would make for easier qualitative comparisons. Would this not go some way towards addressing the ice quality question?

Think Wipneus does a great job and has enough to do without having to edit the graphs to add the numeric information. Also do numbers on a single graph help much? I suspect it is the comparison of those numbers over time that is the useful information and Wipneus provides these graphs. (OK comparison to more years might be wanted but there are limits to what he can do.)
Title: Re: Stupid Questions :o
Post by: Wipneus on July 21, 2014, 07:55:48 PM
Is extent simply the area that exceeds some arbitrary concentration threshold (e.g. 15%)? If so, is there any natural justification for the threshold, or is it arbitrary? More importantly, if it is just a threshold, then why does anyone care about extent? Shouldn't area be paramount?

There are a couple of reasons for this. First area needs sea ice concentration from the whole Arctic. We only have reliable data from the end of 1978 to the present, before that nothing direct. Extent on the other hand can be estimated just from the position of the ice edge. We have useful observations of sea ice sightings since 1800 if not before that. Second the ice concentration from satellite observations in the marginal zones can be 10% or so off, so the cut-off is a trade-off between well above 10% and as low as possible.
Third, different satellite products differ far more in computed area while giving comparable extent values at the same time (even when resolution affect extent more than area). Fourth, even if those difference could be resolved, there is still the factor melt ponds. Unless compensated for, area which you get is not what you expect.

Quote
Taking the idea (that area has more information than extent) one step further, wouldn't it be useful to see area distributions rather than just averages. This is how it is displayed visually, but I haven't seen it tallied up on graphs, which would make for easier qualitative comparisons. Would this not go some way towards addressing the ice quality question?

I am always open to new ideas presenting the information that is out there. If this is one, can you please explain what exactly you would like to see?
Title: Re: Stupid Questions :o
Post by: johnm33 on August 07, 2014, 04:28:01 PM
What are the physics of rising and expanding air [methane] bubbles in sea water? Specifically do they cool as they rise?
Title: Re: Stupid Questions :o
Post by: SteveMDFP on August 07, 2014, 04:45:09 PM
What are the physics of rising and expanding air [methane] bubbles in sea water? Specifically do they cool as they rise?

Any gas will cool as it expands under reducing external pressure.  But the bubbles would constantly also tend to exchange heat with surrounding water.  I'd be surprised if anyone has measured the temp of the gas that results. 

If you're thinking the cold gas could contribute to surface water freezing (or not melting), I'd suggest that any direct effect would be overwhelmed by the mixing action of rising bubbles, which would tend to bring warmish waters to the surface in the arctic. 

Any cooling action of expanding methane might also be overwhelmed over a longer period by bacteria oxidizing dissolved methane into CO2.
Title: Re: Stupid Questions :o
Post by: Peter Ellis on August 07, 2014, 07:04:06 PM
No they do not, especially deeper down at the start of their rise, since they have a small surface area to volume ratio, rise comparatively slowly and thus readily equilibrate in temperature with the surrounding water, i.e. the bubble expansion will thus be largely isothermal.

Edit: removed scuba diving example as it's not just wrong but hilariously wrong

If the bubbles are large and also rise really fast over the last few metres, you might see gas escaping at fractionally below the water temperature. I don't think it would be easily measureable.
Title: Re: Stupid Questions :o
Post by: johnm33 on August 07, 2014, 08:46:53 PM
Thanks for the replies, I was thinking of its cooling effect under the ice but of the larger surface eruptions, say 50-100m,  [or even up to 1000m] where I'm assuming, for now, that there'd be less opportunity to establish equilibrium with the water it rises through.
Title: Re: Stupid Questions :o
Post by: anthropocene on September 06, 2014, 08:53:12 AM
Could somebody with in-depth knowledge answer the following questions. A link to a resource which provides information about arctic atmospheric conditions would be great.
I've recently been taking a course on meteorology.  This introduced me to the ideas of lapse rate and temperature inversions (positive lapse rate) producing a stable atmospheric layer. The example given was on land at night time when the land cools the surface atmosphere producing a stable atmospheric layer (I think it was stated this layer was typically 100-200m thick). This stable layer stops higher level winds reaching ground level and reduces atmospheric mixing (and therefore temperature transfer). This got me to thinking about what happens in the arctic  above the sea ice. For this case lets concentrate on 80degN and above.

1) Because the ice provides a constant cooling force the default state is for there to be a temperature inversion from the ice surface to 100 to 200m altitude?

2) In summer the sun will heat the surface but most of the heat will be reflected. Does the heating from the sun ever get strong enough to destroy the temperature inversion (i.e. set up thermal convection currents at the surface)?

3) Obviously if the sea is ice-free for a significant area then the thermal dynamics will be completely different. Convection will occur and higher altitude winds will transfer to the surface. What happens when these surface winds hit the areas with ice and the stable atmospheric regions? e.g. This air will be warmer so does it rise and ride over the stable air mass or does it push the stable air mass off the ice?

4) During the melting season  temperature maps are often provided. The map shows temperature at a certain pressure which often translates to a certain altitude (I think I remember 500m being mentioned). The assumption seems to be that the temperature at the surface will be higher than this temperature (negative lapse rate is being assumed). If 1) is correct isn't this assumption likely to be incorrect above the sea-ice?
Title: Re: Stupid Questions :o
Post by: Richard Rathbone on September 07, 2014, 12:38:05 PM
Thanks for the replies, I was thinking of its cooling effect under the ice but of the larger surface eruptions, say 50-100m,  [or even up to 1000m] where I'm assuming, for now, that there'd be less opportunity to establish equilibrium with the water it rises through.

These aren't bubble sizes. These are the size of areas within which bubbles were seen.

To use a football analogy, what you are quoting here is the size of the pitch, not the size of the ball.
Title: Re: Stupid Questions :o
Post by: Mike H on September 10, 2014, 11:26:58 PM
For years I have heard the proposition that the disappearance of sea ice produces a significant positive feedback which will accelerate melting and global warming in general. I think I understand the mechanism. However, it has occurred to me that this feedback might be somewhat limited, as the timing of maximum solar insolation occurs much before the maximum amount of open water in the Arctic.

Also, the increase in open water in fall and early winter produces a negative feedback due to extra release of heat to space.

Has anybody tried to estimate the net effects of these two feedbacks ? That is, how much extra ice volume should be lost in spring/summer due to reduced ice area of say, 1 million km2 between 70-80 N ? And how much extra ice volume should be gained due to a similar decrease of ice area during fall/early winter ?

I have tried to follow the math of various forcings but find myself overwhelmed, given that short-term noise (wind and ocean currents, other effects of weather) tend to dominate the action in any given year.
Title: Re: Stupid Questions :o
Post by: jdallen on September 11, 2014, 01:10:11 AM
For years I have heard the proposition that the disappearance of sea ice produces a significant positive feedback which will accelerate melting and global warming in general. I think I understand the mechanism. However, it has occurred to me that this feedback might be somewhat limited, as the timing of maximum solar insolation occurs much before the maximum amount of open water in the Arctic.

Also, the increase in open water in fall and early winter produces a negative feedback due to extra release of heat to space.

Has anybody tried to estimate the net effects of these two feedbacks ? That is, how much extra ice volume should be lost in spring/summer due to reduced ice area of say, 1 million km2 between 70-80 N ? And how much extra ice volume should be gained due to a similar decrease of ice area during fall/early winter ?

I have tried to follow the math of various forcings but find myself overwhelmed, given that short-term noise (wind and ocean currents, other effects of weather) tend to dominate the action in any given year.
This is far from a stupid question ;)

I haven't wrestled with the details of math, instead trying to understand processes.

I no longer think we are on a short path to a *persistently* ice free arctic  I do think over the last decade we have reached a change in hysteresis such that 1) return to pre 2007, perhaps even pre 2000 behavior is not possible for centuries, if ever and 2) short term forcings of weather will have a fair greater role in the state of the ice at the end of any given melt season. My sense right now is, the entire system has been thrown into a state which is to chaotic for us to skillfully predict behavior past a rather short event horizon; a distance measured months at most, weeks more probably.

I'm focusing  now less on the specific state of the ice, and more on the changes in sensible heat in the arctic ocean, and the condition of permafrost around it.  That heat and how accessible it is seasonally will I hope give me a better handle on how the climate is going to change, and how fast.

Title: Re: Stupid Questions :o
Post by: johnm33 on September 11, 2014, 02:22:00 AM
Richard, this http://www.theage.com.au/articles/2003/10/22/1066631498889.html (http://www.theage.com.au/articles/2003/10/22/1066631498889.html) is the best reference I can find about large scale eruptions of the kind I was thinking of, and I'm thinking more of a release of balloons over the pitch [to extend your analogy]. But thats not the question the question is about the physics of that scale of gas release, specifically the cooling effects as the expanding gas rises, especially if it rises to an ice covered surface.   
Title: Re: Stupid Questions :o
Post by: anthropocene on September 11, 2014, 09:27:41 PM
For years I have heard the proposition that the disappearance of sea ice produces a significant positive feedback which will accelerate melting and global warming in general. I think I understand the mechanism. However, it has occurred to me that this feedback might be somewhat limited, as the timing of maximum solar insolation occurs much before the maximum amount of open water in the Arctic.

Also, the increase in open water in fall and early winter produces a negative feedback due to extra release of heat to space.

Has anybody tried to estimate the net effects of these two feedbacks ? That is, how much extra ice volume should be lost in spring/summer due to reduced ice area of say, 1 million km2 between 70-80 N ? And how much extra ice volume should be gained due to a similar decrease of ice area during fall/early winter ?

I have tried to follow the math of various forcings but find myself overwhelmed, given that short-term noise (wind and ocean currents, other effects of weather) tend to dominate the action in any given year.

There was a paper a few months back (sorry no link) which put the total effect of the reduction in albedo in the arctic (IIRC this was total reduction in snow cover, loss of sea ice and reduction in albedo of ica+snow) as 25% of the global effect of GHG added to the atmosphere in the last century. Off the top of my head the effect of GHG is approx 3.2W/m2 so albedo reduction would be increase of 0.8W/m2 when averaged across the whole globe. Of course the actual impact would be much greater if considering just the arctic: The area would be considerably less but in this analogy I can't remember how they handled solar insolation.

Sorry, for heat loss from open sea water I've no idea. I suspect it would be highly dependent on the amount of clouds.
 Most probably the key issue is that as the removal of ice moves closer to the north pole the increase in insolation will get less and the increase in heat loss to space will most probably accelerate. (the amount and type of clouds is the main variable which can complicate this scenario).  Combined together this will be a negative feedback as we move towards an ice free arctic.

Title: Re: Stupid Questions :o
Post by: Richard Rathbone on September 12, 2014, 02:27:17 PM
Richard, this http://www.theage.com.au/articles/2003/10/22/1066631498889.html (http://www.theage.com.au/articles/2003/10/22/1066631498889.html) is the best reference I can find about large scale eruptions of the kind I was thinking of, and I'm thinking more of a release of balloons over the pitch [to extend your analogy]. But thats not the question the question is about the physics of that scale of gas release, specifically the cooling effects as the expanding gas rises, especially if it rises to an ice covered surface.

The thermal capacity of the water in the wake is of the order of 1,000 (for a small spherical bubble) to 10,000 (for a large spherical cap bubble) times that of the bubble. If anything affects the surface, its the water brought up with the bubble. (just as in your linked story, its the wake that sinks the toy boat, not the bubble).
Title: Re: Stupid Questions :o
Post by: kingbum on September 16, 2014, 02:54:45 AM
I got plenty of stupid questions for everyone here.....let me start by saying I'm not a denier of AGW but I also don't accept it blindly provide me evidence and I will listen.....My big thing right now is with the increase in seismic activity we have had worldwide, specifically I'm talking about bardabunga in Iceland and how it seems to be following eerily the same eruption pattern Laki did in 1784....For those who aren't familiar with this read about the winter of 1784 about 6 million deaths in Europe were attributed to SO2 and other gases....which leads me to why I'm posting this question on this forum....given the reduction in TSI and the increase of both ice and SO2 in the atmosphere how can we logically assume that the ice cap in the arctic won't recover more.....just look at Antarctica and the record extent its at and near record area....all of that ice must produce an albedo effect and at what time does all this become like a domino effect? Its just something that's bugging me
Title: Re: Stupid Questions :o
Post by: jdallen on September 16, 2014, 09:28:58 AM

Welcome kingbum and thank you for your willingness to enter into dialog.

Let me take a number of items you list in turn.

...My big thing right now is with the increase in seismic activity we have had worldwide,

That's an illusion of sampling.  The world isn't having more earthquakes.  It's measuring more earthquakes because more seismographs are being installed in more places they've never been before.  If more earthquakes started happening on Iceland, in areas other than that where the volcano is erupting, it might be a reasonable to think there was some connection.

... how it seems to be following eerily the same eruption pattern Laki did in 1784...

That similarly is illusory.  We know rather little about Laki aside from its aftermath - the evidence left lying around after the eruption stopped.  There's very little which we can say about the current eruption which it holds in common with Laki.  Beyond the facts that
1) Its on Iceland in an area split by a crustal spreading center
2) we have a fissure eruption producing a moderate volume of fluid magma
3) there are moderate amounts of gasses typical to Icelandic eruptions being released (SO2, F, CL, CO2, CO, water vapor, et. al.)

... we really can't conclude the current eruption will evolve anything like Laki. It's complete speculation to think so.

....given the reduction in TSI and the increase of both ice and SO2 in the atmosphere how can we logically assume that the ice cap in the arctic won't recover more.....

It's important to avoid the mistake to conclude a small number of events (2) can permit one reliably predict a change.  2013/2014 don't yet imply a recovery.  There need to be quite a few more of them - at least 3 or 4 - before we can start talking recovery.  There would also need to be significant increases in coverage - volume did increase year over year 2013/2014 - but still not so much that they made it back to pre-2007 levels.  2013/14 Area and Extent are in a dead heat.  That outcome was driven by weather and feedbacks to the 2012 melt, which it seems was way outside of the trend.

Further, the impact of aerosols from the current eruption will not be enough in scale, or importantly persistent enough to seriously influence the ice.  Smoke from the wildfires in Canada and Siberia are more likely to affect the state of the ice than volcanic gasses, even if we reach "Laki" levels of emissions.

....just look at Antarctica and the record extent its at and near record area

Once again correct in fact, but incorrect in underlying assumption - that the increase of Antarctic ice signals some sort of recovery in the system.  The best research suggests that ice in the Antarctic is in rather dire straights - a number of large shelves have disintegrated over the last few seasons, and warm southern water has undermined and mobilized sheets of ice coming off of the west antarctic sheet.  The "recovery" is the product of a feedback which has tended to isolate the Antarctic from intrusions of warmer air from lower latitudes.  The effect isn't more ice so much as it is greater volatility.  The heat entering the system is still increasing.

....all of that ice must produce an albedo effect and at what time does all this become like a domino effect? Its just something that's bugging me

The "dominoes" are neither massive enough nor numerous enough to change the trend.  Albedo is just one component of the system as a whole, which affects heat transfer.  There are many other aspects of the system which would require significant positive change to affect.
Title: Re: Stupid Questions :o
Post by: viddaloo on September 16, 2014, 11:57:08 AM
Albedo during polar Winter is also close to insignificant, yet as we now enter into Antarctic Spring, it may play an increasing role.
Title: Re: Stupid Questions :o
Post by: crandles on September 16, 2014, 02:36:21 PM
..given the reduction in TSI and the increase of both ice and SO2 in the atmosphere how can we logically assume that the ice cap in the arctic won't recover more.....just look at Antarctica and the record extent its at and near record area....all of that ice must produce an albedo effect and at what time does all this become like a domino effect? Its just something that's bugging me

SO2 needs to get up into the stratosphere for it to be long lasting and produce a cooling effect. Even if there was a large eruptive event this effect only lasts three years and that is for event in tropics. Near Arctic the effect is less clear as there are counteracting effects. Some Ash SO2...won't get high enough so will not be long lasting in atmosphere so the main effect would be pollutants on the ice which makes it easier for the ice to melt. We may well not have a large eruptive event so this melting ice effect may dominate.

Anyway best scenario would be a three year temporary blip then atmospheric sulphur conditions would be back to where they are and CO2 and other GHG would be higher than now.

Antarctica
It does look like there will be a record ice area for Antarctica. A good part of the explanation for this seems to be higher winds probably caused by shift in the polar cell in turn probably caused by ozone loss. OZone hole seems to have steadied and may be showing signs of a very slow recovery.

Higher winds may be causing more rapid movement of ice so that it is thinner but travels further. I am not sure whether it is clear whether there is more sea ice or not.

If the cause of the higher winds has ceased to get stronger then it is possible that other effects may start to overwhelm this current dominant effect. I don't know how long this might be. Does anyone? What do you suppose might start to dominate? Higher ocean temperatures? GHG levels? Can you name more likely effects that would further increase sea ice extent?

There seems to me to be a big difference between something we know is continuing to increase in effect, like GHG levels, and something where we know the cause seems to be ceasing if not reversing like Antarctic sea ice levels.

Domino effect
There does appear to be positive feedback in the system. This should not be confused with runaway positive feedback. Runaway positive feedback seems extremely unlikely and is not expected. If conditions for this ever existed then we wouldn't have a long history of a survivable climate for life on Earth. The positive feedback we have got is more like a temperature increase of 3C causes a 1C increase. That 1C increase causes a further 1/3C increase which in turn causes a 1/9C increase and so on. Thus the 3C forcing increase causes an eventual total temperature rise of 4.5C.

We have been cooler in the recent past so there is no reason to expect a runaway event in the cooling direction. Similarly we have been warmer perhaps 6000 years ago also in Eocene and other longer ago times, therefore there is no reason to expect a full blown Venus style runaway effect in the warming direction. A more limited runaway effect in warming direction if permafrost and methane hydrates are destabilised may be low probability possibilities in the warming direction but I don't see any possibility for something like that in the cooling direction; GHG levels are simply too high and going upwards not downwards. While other things can be larger than GHG levels over a few years, GHG level effects keep accumulating so that over three decades or more GHG clearly dominate.
Title: Re: Stupid Questions :o
Post by: viddaloo on September 30, 2014, 10:23:11 PM
Also, could someone explain to a novice why we talk about a '40-year delay' of CO2 emissions before they take effect? Does that imply NO radiative forcing of temperatures for 40 years?
Title: Re: Stupid Questions :o
Post by: jdallen on September 30, 2014, 10:59:02 PM
Also, could someone explain to a novice why we talk about a '40-year delay' of CO2 emissions before they take effect? Does that imply NO radiative forcing of temperatures for 40 years?

Not quite correctly stated.

More correct would be... 40 year delay before the effects are *felt*.  The radiative forcing is taking place.  The lag is how long before the sensible heat increases they cause reach a new balance with the changes in forcing.
Title: Re: Stupid Questions :o
Post by: viddaloo on September 30, 2014, 11:11:47 PM
Thx. But CH4, by contrast, is felt immediately through local heating?
Title: Re: Stupid Questions :o
Post by: Laurent on September 30, 2014, 11:39:18 PM
I think (not sure) that almost all the heat goes into the oceans (because they absorb the heat and because it is 70 % of the surface). 40 years must be the shortest of the oceanic cycles, where we see the heat that is stored is upwelled on the surface. Last time I asked a scientific, he said a drop of the ocean can take 500 years to go around the full cycle of the oceanic currents.

All the gazes have a direct effect, Ch4 is 200 times less than CO2 (nearly 2ppm compared to 400 ppm of CO2). I do think it is the direct effect that is important not the one calculated for 100 years (because it is calculated for a decaying amount, but when it is replenish...) Ch4 is also said to be 100 times more powerfull so...(Would love to have official datas)
Title: Re: Stupid Questions :o
Post by: crandles on October 01, 2014, 12:34:31 AM
Thx. But CH4, by contrast, is felt immediately through local heating?

Not sure if it creates much local heating. But so what if it does? Urban heat island effect is not considered an important forcing is it? So effect of adding to long term radiative forcing seems more likely to be the worrying effect?

Quote
The radiative forcing is taking place.  The lag is how long before the sensible heat increases they cause reach a new balance with the changes in forcing.

I would suggest you need a lot of radiative forcing imbalance to get the ocean temperatures moving upwards and well over 100 years for ocean temperatures to get anywhere close to reaching equilibrium with the radiative forcing. What happens to ocean temperatures this year could well be mainly noise but the underlying trend depends mainly on last 40 years of radiative forcing imbalance. So something vastly different than usual anthro emissions would have an effect beginning immediately (and lasting for 100 years+ before ocean temperatures catch up). Note that something different from 10Gt of carbon emissions like 50Gt, sounds like a big difference but when you add it to 300Gt over last 40 years, 350 versus 310 doesn't seem like such a large difference (less than 13%). 

However emissions are generally growing quite smoothly so you rarely, if ever, get anything 'vastly different than usual anthro emissions'. Hence even with a different emission path where the emissions grow more different each year it still takes a long time of these growing accumulated RF difference before the expected temperature path differs significantly.


The short explanation for a novice is that it is the huge thermal inertial of the oceans.
Title: Re: Stupid Questions :o
Post by: viddaloo on October 01, 2014, 02:09:32 AM
Not sure if it creates much local heating. But so what if it does? Urban heat island effect is not considered an important forcing is it? So effect of adding to long term radiative forcing seems more likely to be the worrying effect?


There is the element of thawing even more methane hydrates creating even more local heat in the same area, if already thawing seabed hydrates are the source of the methane causing local warming. So there is that....
Title: Re: Stupid Questions :o
Post by: crandles on October 01, 2014, 02:31:24 AM
There is the element of thawing even more methane hydrates creating even more local heat in the same area, if already thawing seabed hydrates are the source of the methane causing local warming. So there is that....

How deep do you think these seabed hydrates are and how much thermal inertia does that sea provide?

Permafrost giving off methane, causing some local warming, causing more permafrost degradation may be a little more plausible. Even then I have difficulty imagining there being enough methane being released for it to linger around enough to create much of a local heating effect and then the heat has to get through the active layer to the permafrost and that has to release sufficient extra methane to at least maintain the locally higher temperature rather than winds dispersing it.

Perhaps I am just being unduly sceptical of this?
Title: Re: Stupid Questions :o
Post by: viddaloo on October 01, 2014, 03:09:26 AM
Perhaps :D

The ESAS — Eastern Siberian Arctic Shelf — is a vast and very shallow part of the ocean. If conditions in the seabed are already thawing before the CH4 driven local warming, this could push things over the edge and secure an even bigger release.
Title: Re: Stupid Questions :o
Post by: jdallen on October 01, 2014, 05:55:30 AM
The obstacle for a prompt release of ESS hydrates is a sufficiently large and persistent heat source.

They hydrates are buried in sediment, which itself is close to 0C or below.  Before the hydrates can disassociate, you need to heat *that*, as well as provide the heat necessary to permit the phase change.  That much mass won't heat up fast, or uniformly.

The greater probability favors a slower, more uniform release.
Title: Re: Stupid Questions :o
Post by: viddaloo on October 01, 2014, 06:48:26 AM
IMO, the Laptev Sea with currently 4+ anomalies will be that persistent heat source. Local CH₄ heatwaves will just add hurt to the injury.

The IPCC, BTW, says in its 5th report that seabed hydrates cannot melt, which is very reassuring. I feel so safe. Their argument is that the shallow seawater will expand due to the warming and thus increase the pressure on these hydrates. IPCC saves the day!
Title: Re: Stupid Questions :o
Post by: wili on October 01, 2014, 10:47:57 AM
"hydrates are buried in sediment"

They aren't all uniformly buried in sediment. Along slopes, the hydrate strata meets the water, and that is exactly where people are worried about. Break down of hydrate on slopes can also lead to submarine landslides which could uncover further hydrate...

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.ruf.rice.edu%2F%7Ehydrates%2Fimages%2Fimg004.jpg&hash=9c599a9cc9afd4768e5a107b2cbc3366)

http://www.ruf.rice.edu/~hydrates/about.html (http://www.ruf.rice.edu/~hydrates/about.html)

(Keep in mind that when it is directly exposed to sea water like this, melting is subject not only to increases in warming and decreases in temperature, but also to changes in salinity. )

Warming of such slope areas could come not only from above (as more and more of the ocean is ice free for more and more of the summer), but also potentially from changes in sea currents. Warm currents from the Atlantic have been intruding further and further into the Arctic recently, iirc.

Besides, the 'sediment' is largely sub-sea permafrost, as I understand it, which is itself subject to melting.

Furthermore, there can be trapped free gas beneath the hydrates.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fenergy.gov%2Fsites%2Fprod%2Ffiles%2Fstyles%2Fborealis_default_hero_respondlarge%2Fpublic%2Ftypes_methane_hydrate_deposits.jpg%3Fitok%3D012O9b5s&hash=6ace69532894b1ef36b60f486155a163)

http://energy.gov/fe/science-innovation/oil-gas-research/methane-hydrate (http://energy.gov/fe/science-innovation/oil-gas-research/methane-hydrate)

And again, there are big uncertainties in the models for how the Arctic will respond to warming.

http://www.sciencedaily.com/releases/2014/09/140926101859.htm#sthash.3eBFunfe.dpuf (http://www.sciencedaily.com/releases/2014/09/140926101859.htm#sthash.3eBFunfe.dpuf)


 
Title: Re: Stupid Questions :o
Post by: Peter Ellis on October 01, 2014, 12:28:18 PM
Some while back the folks at RealClimate ran the numbers and showed that sea floor volcanic eruptions can't have any effect on sea ice cover - there's just too much water in between, so the extra heat at the bottom of the ocean gets dispersed and has no measurable effect at the surface.

I think all of us on this forum intrinsically agree with that.  We don't buy the denialist trope of "OMG LOOK AT THE VOLCANOES!" and instead understand that the sea ice retreat is driven by global changes in heat dynamics rather than by small scale local effects.


Now, turn that model upside down and consider the converse situation of a localised methane "burp" which raises the temperature of the surrounding atmosphere by a few degrees. Just the same way a localised volcano _under_ the sea can't melt the ice at the _top_ of the sea, a localised warm air patch at the _top_ of the sea can't melt the hydrates at the _bottom_ of the sea.  It's just too small-scale and local to be even worth considering.
Title: Re: Stupid Questions :o
Post by: Peter Ellis on October 01, 2014, 12:33:33 PM
To forestall the next comment:

Yes, I know the volcano analysis was talking about the deeper ocean rather than the ESAS.  Given that you're talking about a couple of km depth compared to 50m depth, that's a little under two orders of magnitude difference. 

Might that mean that warm air can melt buried hydrates even though a volcano can't melt sea ice?

No, because the rock is at ~1000 degrees above ambient temperature, while the putative warm air patch from methane release is at best a few degrees above ambient - so there's your two orders of magnitude the other way in terms of heat flow.  Moreover, the specific heat capacity of rock is much higher than that of air, so you have yet more orders of magnitude difference going the other way.


It's just not remotely physically plausible.
Title: Re: Stupid Questions :o
Post by: jdallen on October 01, 2014, 06:21:50 PM
Wili - I will grant your points.  That said, even with them, catastrophic release of ch4 is still dependent on the *specific* confluence of multiple conditions - the right distribution of hydrate, the right temperature, the right salinity, the right sub-surface topography (on a large scale...) a lot of "rights" to line up. I'm very dubious they add up to catastrophic release.

Permafrost adds its own ch4 contribution, but similarly, requires a large input of heat to unlock.  The key to my argument is, that even with the current incremental warming, neither the available heat nor the rate of transfer are high enough to support prompt release - gigatons over the course of a single melt season.

Do not mistake me though; I consider the methane release from clathrate and permafrost to be a serious problem.  I just don't think it will present itself in sudden events.
Title: Re: Stupid Questions :o
Post by: wili on October 01, 2014, 07:15:48 PM
"catastrophic release of ch4 is still dependent on the *specific* confluence of multiple conditions - the right distribution of hydrate, the right temperature, the right salinity, the right sub-surface topography (on a large scale...) a lot of "rights" to line up. "

I think that's true, and more (you forgot 'right pressure'--we can hope that destabilization will hold off till sea level rises enough to put enough added pressure on the buggers to keep 'em in place).

But I'm less sure that we know for certain how unlikely such a line up may be.

In any case, the main focus must remain on crashing our emissions down as fast and as far as possible, to avoid known unknown and unknown unknown dangers, and to give any unknown unknown negative damping feedbacks a chance to save our sorry @$$es in spite of ourselves.
Title: Re: Stupid Questions :o
Post by: johnm33 on October 02, 2014, 10:49:31 AM
If an explosive reaction between salt and methane 70m [ish] below the surface in permafrost can happen onshore surely it can happen offshore too? Is there any evidence of such 'pockmarks' on the seabed of the ESAS or on the slopes of the continental shelves? I'm thinking such intrusions allowing [+4c?] water access to hydrate layers can only accelerate methane release? Ashore, if i understand correctly, the gas fields are directly below the permafrost layer and it's these depths that are the main source of methane outgassing in lakes, so i guess it's just a matter of luck whether one of these type of events 'tap' into a serious gas deposit or not, on land or at sea.
 Of course the argument holds even if there's a different explanation for the 'siberian holes'.
Title: Re: Stupid Questions :o
Post by: Peter Ellis on October 02, 2014, 03:47:58 PM
If an explosive reaction between salt and methane ...
I've seen this one noised around as an explanation for the Siberian crater, and I can't follow it at all.  Salt doesn't react with methane.  All efforts to trace this to its source end up at the Daily Mail.  I'm not going to believe it until someone with a relevant chemistry qualification posts the equation for the chemical reaction concerned and explains the mechanism.
Title: Re: Stupid Questions :o
Post by: jdallen on October 02, 2014, 09:55:24 PM
If an explosive reaction between salt and methane ...
I've seen this one noised around as an explanation for the Siberian crater, and I can't follow it at all.  Salt doesn't react with methane.  All efforts to trace this to its source end up at the Daily Mail.  I'm not going to believe it until someone with a relevant chemistry qualification posts the equation for the chemical reaction concerned and explains the mechanism.
Salt reacting with methane to cause an explosion quite simply is nonsense.

Methane release from warming will be an agonizing slow trial of a thousand cuts, not some apocalyptic evulsion.  That in no way detracts from how serious a problem it poses.

The eventual stable result will be a significant increase in atmospheric CO2. That is the problem we need to avoid.
Title: Re: Stupid Questions :o
Post by: johnm33 on October 04, 2014, 01:57:25 PM
This is not where i first read of the idea but the names right "Anna Kurchatova from the Sub-Arctic Scientific Research Centre thinks the crater was formed by a water, salt and gas mixture igniting an underground explosion, the result of global warming. "[ From http://siberiantimes.com/home/ (http://siberiantimes.com/home/)] being unencumbered myself by a formal education in chemistry i assume she's basing this on something.   
I've just gone through the 'siberian hole' thread and it seems something similar does happen on the ESAS.
Title: Re: Stupid Questions :o
Post by: Andreas T on October 05, 2014, 01:40:23 PM
the article here http://siberiantimes.com/science/casestudy/news/first-pictures-from-inside-the-crater-at-the-end-of-the-world/ (http://siberiantimes.com/science/casestudy/news/first-pictures-from-inside-the-crater-at-the-end-of-the-world/) talks about the 'explosion' being like the popping of a champagne cork. The term explosion gets used loosely in the media with different meanings. Reading the whole article it also points out that there are no signs of burning so you should not think of a fireball kind of explosion just because it involves a flamable gas. Without more details it is difficult to interpret what the interaction between salt ice and gas is (probably not a chemical reaction), but it is more likely something which involves repeated melting and freezing over years creating the conditions where gas is released but builds up into a contained bubble and then burps and flips some muddy earths aside as it escapes. the depth of the whole may well be due to melting ice which has lost a protective layer of earth.
Title: Re: Stupid Questions :o
Post by: viddaloo on October 20, 2014, 10:36:55 PM
I wonder how it is that Earth is only just within the Sun's habitable zone (http://www.nature.com/news/earth-is-only-just-within-the-sun-s-habitable-zone-1.14353) (Nature 2013), and still Ice was apparently most widespread during the last 2–3 million years, in accordance with Earth's overall cooler climate (http://neven1.typepad.com/blog/2012/08/wasislac.html) (ASI Blog 2012).

Is the Cryosphere in a regular eon overcompensating for the Earth's closeness to the Sun? Strange effect, but it seems to support lifeforms pretty well and for long periods of time.
Title: Re: Stupid Questions :o
Post by: Peter Ellis on October 21, 2014, 01:08:39 AM
Viddaloo:  There are at least four competing effects going on, across vastly differing timescales. Going from fastest to slowest scales, we have:

1) Milankovic cycles - the precession of the Earth's axis of rotation in relation to its orbit.  This currently favours ice growth.

2) Continental drift - the continents are currently in a configuration that favours ice growth, with land at one pole and a fairly isolated ocean basin at the other.  In contrast, when land is clustered round the Equator and the poles are open deep ocean, it is much harder for stable ice caps to form there.

3) Global CO2 budget - notwithstanding recent anthropogenic CO2 releases, overall CO2 levels have been dropping intermittently since the Carboniferous.  After all, all that coal we're burning now came from somewhere, and much of it was CO2 in the atmosphere.

4) Solar evolution - the Sun is gradually getting hotter, as is typical for stars of this type at this stage of their life cycle.


It's important to understand that the _amount_ of CO2 released, and indeed the overall temperature of the planet, is not the major problem with AGW.  The problem is the _rate of change_, meaning that habitats will alter and seas rise faster than living things can cope with.  The absolute temperatures and sea levels involved won't be anything particularly unusual in the geological record.
Title: Re: Stupid Questions :o
Post by: viddaloo on October 21, 2014, 01:15:56 AM
Thanks, Ellis. I would have expected Earth to be at the outer (colder) rim of the habitable zone (around the Sun) when 'recent' status was a Snowball Earth type glaciation, and, as I understand it, without humans we'd be moving in the direction of an even colder state than 2–3 million years ago.

That's why I had to google the 'habitable zone' statement and re–read the Nature piece. Nature says we're just outside of the Sun–distance that would have made Earth too hot for life. Hard to reconcile.
Title: Re: Stupid Questions :o
Post by: DavidR on October 24, 2014, 01:43:50 PM
Recently I  accessed a web site that  gave annual and monthly temperature anomalies for selected latitude ranges. eg 60-90 N or 66-90 N or 60-90 S. It suggested that June 2014 the Arctic was comparatively cold.  Stupidly I forgot to bookmark the site. If any one has a link that provides that information I would appreciate it.
It cannpt be coincidental that  June was very  cold in the record and July  had little melt.
Thanks in anticipation.
Title: Re: Stupid Questions :o
Post by: Jim Hunt on October 24, 2014, 09:25:17 PM
Recently I  accessed a web site that  gave annual and monthly temperature anomalies for selected latitude ranges. eg 60-90 N or 66-90 N or 60-90 S. It suggested that June 2014 the Arctic was comparatively cold.  Stupidly I forgot to bookmark the site. If any one has a link that provides that information I would appreciate it.

Was this (http://www.esrl.noaa.gov/psd/cgi-bin/data/composites/printpage.pl?var=Air%20Temperature;level=Surface;mon1=5;mon2=5;iy=2014;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;iy=;itimefile0=;tstype=0;timefile1=;value=;typeval=1;compval=1;lag=0;labelc=Color;labels=Shaded;type=2;scale=100;labelcon=1;switch=0;cint=;lowr=;highr=;proj=Custom;xlat1=60;xlat2=90;xlon1=0;xlon2=360;custproj=Northern%20Hemisphere%20Polar%20Stereographic;level1=1000mb;level2=10mb) the link by any chance? Here's the resulting anomaly plot:
Title: Re: Stupid Questions :o
Post by: ChrisReynolds on October 24, 2014, 10:01:36 PM
Recently I  accessed a web site that  gave annual and monthly temperature anomalies for selected latitude ranges. eg 60-90 N or 66-90 N or 60-90 S. It suggested that June 2014 the Arctic was comparatively cold.  Stupidly I forgot to bookmark the site. If any one has a link that provides that information I would appreciate it.
It cannpt be coincidental that  June was very  cold in the record and July  had little melt.
Thanks in anticipation.

Need more of a clue. GISS do latitude bands but only for annual means, so 2014 won't be included.
http://data.giss.nasa.gov/gistemp/ (http://data.giss.nasa.gov/gistemp/)

The link Jim gave is to a site that isn't working due to data outage:
http://www.esrl.noaa.gov/psd/cgi-bin/data/composites/printpage.pl (http://www.esrl.noaa.gov/psd/cgi-bin/data/composites/printpage.pl)

But their NCEP/NCAR reanalysis timeseries, from which you can get numeric data is working.
http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl (http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl)
Let me know if you need guidance, should you want to use that.
Title: Re: Stupid Questions :o
Post by: Fisch on October 25, 2014, 06:13:40 AM
Medium-time lurker, first-time poster, likely to stay a lurker outside this thread.

I've noticed that on the chart shown here:

http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/ice_volume/Bpiomas_plot_daily_heff.2sst.png (http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/ice_volume/Bpiomas_plot_daily_heff.2sst.png)

Max/min thickness seems to arrive about a month/month-and-a-half after when max/min extent/area/volume arrive. Anyone know the reason behind this?
Title: Re: Stupid Questions :o
Post by: ChrisReynolds on October 25, 2014, 08:38:01 AM
Sorry Jim,

Yes it is working, I hadn't scrolled down, looks like most of what people here need will be available.
Title: Re: Stupid Questions :o
Post by: crandles on October 25, 2014, 12:15:43 PM

Max/min thickness seems to arrive about a month/month-and-a-half after when max/min extent/area/volume arrive. Anyone know the reason behind this?

The thickness is average thickness. When the freeze begins it adds lots of area of thin ice while it isn't cold enough to thicken thick ice. Thus the average thickness continues to decline past the point where ice is being added.

Similarly when the melt begins, it begins by melting out thin ice.
Title: Re: Stupid Questions :o
Post by: DavidR on October 25, 2014, 02:31:30 PM
Thanks Chris,
The third reference appears to be the one I lost. It shows June 2014 as one of the coolest Junes in the past 65 years, which says a lot about why the melt in July  was so low. 
Title: Re: Stupid Questions :o
Post by: viddaloo on October 25, 2014, 02:42:24 PM
This one, DavidR?

Seems like an error:
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.esrl.noaa.gov%2Fpsd%2Ftmp%2Fclimindex.46.157.158.69.297.6.40.20.png&hash=071bd38ab5391d3b8ce52040ec2bc53e)
Title: Re: Stupid Questions :o
Post by: ChrisReynolds on October 25, 2014, 06:59:15 PM
Thanks Chris,
The third reference appears to be the one I lost. It shows June 2014 as one of the coolest Junes in the past 65 years, which says a lot about why the melt in July  was so low.

Good, damned useful page that one, shame you can't do it on a daily basis, but I'll make do with monthly.

Viddaloo,

I don't think it's in error. Of course as PIOMAS uses that NCEP/NCAR reanalysis as its atmospheric component arguing for the large volume increase being so striking against the previous volume drops as evidence for such cool temperatures seems rather circular. But I doubt if the Cryosat 2 data will fail to support PIOMAS.

Summer has generally been cold, back to 1980s levels. But the previous trend of summer warming suggests to me that this will be just a blip. We'll know in a couple of years whether we should start considering a regime shift to weather that aids ice retention.

(https://farm4.staticflickr.com/3940/15600912306_1b1b931dc9_o.png)

Jan Feb March (overlapping December does not work) temperatures are still rising massively.

(https://farm6.staticflickr.com/5613/15003848254_550a0c0320_o.png)

So if there is a regime change there is no evidence of it in Winter.


Both images are surface temperature north of 80degN to be close as possible to DMI temperatures.
http://ocean.dmi.dk/arctic/meant80n.uk.php (http://ocean.dmi.dk/arctic/meant80n.uk.php)
But that uses the ERA40 reanalysis.
Title: Re: Stupid Questions :o
Post by: viddaloo on October 25, 2014, 07:19:16 PM
Thanks, Chris.

Do you think forest fire smoke can explain this sort of record cold Solstice? Blocking out sunshine more than ever should make a cold month, don't you think? Other explanations I haven't thought of?
Title: Re: Stupid Questions :o
Post by: jdallen on October 25, 2014, 11:41:48 PM
Thanks, Chris.

Do you think forest fire smoke can explain this sort of record cold Solstice? Blocking out sunshine more than ever should make a cold month, don't you think? Other explanations I haven't thought of?

Speculation, with some supporting physics.

Increased open water means increased evaporation. 

The evaporation would tend to pull SSTs back to close to zero or slightly below. 

Evaporation also increases albedo via increased cloud cover.

I don't think we need to look too much further to identify a mechanism supporting steady/slightly cooler summer temperatures.  Heat required for phase change could more than make up for the drop.
Title: Re: Stupid Questions :o
Post by: Steven on October 25, 2014, 11:47:07 PM
Seems like an error:
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.esrl.noaa.gov%2Fpsd%2Ftmp%2Fclimindex.46.157.158.69.297.6.40.20.png&hash=071bd38ab5391d3b8ce52040ec2bc53e)

Yes this seems to be an error.  The longitude range in the title of your graph goes from 0°W to 0°W, so I guess the graph only shows data for the (Greenwich) prime meridian.  You should probably select a longitude range from 0° to 360°, and perhaps also select the option "Area weight grids: Yes" on the above linked webpage (http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl).
 
Title: Re: Stupid Questions :o
Post by: ChrisReynolds on October 26, 2014, 09:03:02 AM
Thanks Steven, I missed that.  :-[

Viddaloo,

There have been fires before together with warm summer temperatures over the sea ice. I think the weather is more likely a candidate. In a study by Ramathan (IIRC) Asian particulate polution was found to increase insolation absorption in the mid troposphere, warming the atmosphere aloft. If it happened like that in the Arctic it might reasonably be expected to increase infra red back radiation, Ice is 'black' in infra-red, absorbing IR. Whereas in visible light it is white reflecting much of the sunlight (although you'd have to factor in albedo drop in summer). So smoke in the Arctic might not produce as much of a drop in net absorbed downwelling radiation (IR + visible) as one might suppose.
Title: Re: Stupid Questions :o
Post by: ChrisReynolds on October 26, 2014, 09:28:46 AM
June temperature attached.
Title: Re: Stupid Questions :o
Post by: Fisch on October 27, 2014, 02:30:05 AM

Max/min thickness seems to arrive about a month/month-and-a-half after when max/min extent/area/volume arrive. Anyone know the reason behind this?

The thickness is average thickness. When the freeze begins it adds lots of area of thin ice while it isn't cold enough to thicken thick ice. Thus the average thickness continues to decline past the point where ice is being added.

Similarly when the melt begins, it begins by melting out thin ice.
Thank you kindly.

A while back, Planet3.org ran a piece on methane, and the comment discussion turned to Shakhova et al. Andy Skuce was involved, and he noted:

"The quantitative results of [Shakhova and Semiletov's] 'field experiments' have gone publicly unreported since 2010, despite the fact that, from second-hand reports, S&S consider that their findings mandate urgent action."

Not being a scientist of any kind, or especially skilled in following the language used in science writing, I don't know what this means. Shakhova et al have been publishing papers since 2010. So are the "quantitative results" the actual records of emissions from specific sites? Detailed maps showing pockmarks and taliks on the seafloor? Sonar maps? And what is the nature of their experiments?

(I asked this over at Planet3, but got no response; it's a fairly old thread.)
Title: Re: Stupid Questions :o
Post by: wili on November 29, 2014, 01:41:30 AM
So, I assigned the intro to Lynas's Six Degrees to one of my classes. Someone in the class pointed to the passage that talks about how, even though 6C may not sound like much, it was the difference between today's relatively temperate NYC and an iceage era NYC area with a mile of glacier over it.

But someone else pointed out that you could probably go a couple hundred miles north of NYC and the temperatures on average would be that much colder than NYC today, but it (say, Nova Scotia) is not under a mile of ice. (She actually didn't quite say it that clearly, but that was the gist.)

I kind of waffled at the time. But when I looked into it, I found something unexpected (to me at least--probably completely 'duh' obvious to the rest of you):

First of all, apparently the cooling distributed evenly over the surface of the earth. There was less or none of it over the equatorial/tropical regions, especially over water. (So that's the first question--Is that anywhere near the ball park? It makes sense to me, but lots of things end up being rather counter intuitive in this field, I find.)

Second (and this was the part that I found a bit surprising), the distribution of the cooling across the year was also not evenly distributed: the winters over much of the norther hemisphere were actually a bit warmer than current averages. I always thought of the ice age as unimaginably cold. But over much of the north it may have been a bit warmer (but longer) than what we experience in MN. All you need to freeze things is for temps to be generally below 0 C enough of the time that warming spells don't totally thaw it.

So a longer, though warmer, winter combined with a shorter and much cooler summer was enough to tip the balance in much of the NoHem so that more ices was formed every winter than was melted every summer...and then it's just a matter of piling on the years and the ice layers.

Does that sound about right? I foraged this from a number of sources that I can't recall right now. So if anyone has any points where I'm off (or especially if I'm completely full of bollocks!) or if you can point me to any (perhaps slightly user friendly?) sources to shore up my weak understanding of these things, it would be greatly appreciated.

Those effects have to do with how the sun hits the earth and affects the seasons when the tilt of the axis goes closer to straight up and down; so far northern and far southern climes are not tipped as directly toward the sun during their summers, hence the cooler summers. But conversely they are tipped closer to the sun during their winters, hence the warmer winters.

Thanks ahead of time for any corrections, pointers, or even face palms  ::) !
Title: Re: Stupid Questions :o
Post by: OSweetMrMath on November 29, 2014, 04:13:18 AM
Wili,

I went poking around on Wikipedia to try to understand the current climate of New York City and what it would be like at 6C cooler. Climate information on Wikipedia is remarkably inconsistent (otherwise identically formatted tables on different pages having additional or missing rows and columns, etc.) so I can't point to a bunch of references to back my claims up, but here is my impression:

If you are asking what a local temperature change of 6C would do to New York's climate, the first question is whether that's before or after the urban heat island effect. The annual mean temperature for NYC is around 15C, but with a large UHI boost. Without that effect it would be closer to 12C.

Assuming we're talking after the UHI, we're looking for somewhere in Canada with an annual mean around 6C. This is where my Wiki searching really started to fail me, but my impression is that Nova Scotia isn't far enough north to be that cold. (Because it's an island, the ocean has a strong moderating effect on the temperature.) You might have to go closer to the mouth of the St. Lawrence to be in the right temperature range, but I was unable to find a good comparison.

My readings generally supported your other two claims. It's easy to imagine that warmer winters and colder summers would result in a much longer snow season.

And on the point that temperature changes are not globally uniform, the discussion of the NYC climate pointed out that NYC is currently much warmer than most other American cities of the same latitude, again largely due to the moderating effect of the Atlantic Ocean. It's reasonable to assume that with a large global temperature change, NYC would lose that effect and see a much larger temperature change than the global mean change.
Title: Re: Stupid Questions :o
Post by: Laurent on November 29, 2014, 10:30:42 AM
Wili,

If the question was :
what will happen if -6°c in average happen ?
If I am correct reading the various graphs, It has never happened in the million year.
At the last glacial low we were at -5°c and there was some glaciers in Florida.

What will happen if +6°c happen :
The Antarctic is melted, it is hot, it did happen around mid eocene, 40 million years ago.

The last graph show around -3°c instead of -5°C in Hansen (not sure if I am reading that correctly). I don't know what that mean equivalent Vostok delta T ! Certainly the average temperature in Vostok !?

Rereading your question, I want to say that yes there was some big differences between winter and summer, but I don't think life was possible inland under a mile thick of ice. Around New york, yes it was certainly possible because of the sea nearby, look at what is happening in Antarctic, life is thriving near the sea.
Title: Re: Stupid Questions :o
Post by: wili on November 29, 2014, 02:47:06 PM
Thanks for the discussion, L and OSMM.

I didn't mean for the discussion to be particularly around NYC and Nova Scotia--those were just examples from the 6 Degrees book and my random jab at a place sufficiently far north. But yeah, they're both unfortunate choices for random examples in that they both are heavily influenced by the ocean.

I was mostly interested in the apparently uneven distribution of heat (or of the cooling, if you will) in both space and (especially) time (over the course of a year).

Thanks especially for the cool graphs, L. I love graphs!
Title: Re: Stupid Questions :o
Post by: crandles on November 29, 2014, 03:02:34 PM
Warming or cooling is generally greater over land than oceans. There is also usually polar amplification - more so in the Arctic than Antarctic particularly for recent periods but if you go back to the Eemian without ice sheets then the polar amplification should be more similar.

If going back a long period of time you may also have to consider Milankovitch cycles. A more tilted earth can give a lot more insolation to high latitudes during the summer and this can make the difference to whether the snow and ice manages to melt.
Title: Re: Stupid Questions :o
Post by: crandles on November 29, 2014, 03:16:03 PM
Here is a review article of history of Last Glacial Maximum (LGM) science:

http://www.sciencedirect.com/science/article/pii/S0277379114003679 (http://www.sciencedirect.com/science/article/pii/S0277379114003679)
(freely available until 23rd December)

Estimates have varied but latest estimate is 4C global average cooler than now preindustrial for LGM. I'd suggest a few thousand miles nearer pole would be needed to keep the same temperature. If a species can't move that fast/far perhaps easier still is move up a few hundred meters. Trouble is as you move up and so does everything else, space soon runs out as you approach top of mountains.
Title: Re: Stupid Questions :o
Post by: viddaloo on December 11, 2014, 10:57:31 PM
— The path to perennial open water is paved with local and seasonal zeros!

If you want to get to a state of zero ice everywhere all days of the year, you will need a lot of zeros. In fact, a sea ice volume of zero for any given location or day is the lowest that data point can go, and therefore 'the best' from the perspective of getting to zero fast.

Now, on this forum the majority of those who speak out on the issue of decline speed and hitting zeros seems to be of the opinion that getting a lot of zero data points is *BAD* for the decline speed. That will slow the decline down, seems to be the conventional wisdom on this site. The graph will flatten or at least become less steep, when lots of points report a zero.

How can this be? From the amateur perspective the thaw couldn't do any better than, say, increase the number of ice–free days in the southern Arctic oceans from 100 to 200. It can't get to the Big Zero without the southern Arctic oceans reporting 200 ice–free days, and later 365 ice–free days a year.

According to experts, the same amount of energy used to melt a square meter of sea ice from 0C ice to 0C water on one day, could heat the same square meter of sea from 0C water to 80C water temperatures on the next. Of course, this doesn't happen exactly like that, but the example communicates how hard it is to melt ice, and how much the Arctic oceans will be heated (by the sun etc) when that ice is gone. Relevant in our context is that nothing stops at zero ice volume.

I put it to you: Instead of slowing the decline down, the complete melt of an increased area or an extra day will *SPEED UP* the decline rate, and increase the steepness of the collapse graph.

[I post this text in the Stupid Questions department, as in the great Nordic tradition of H.C. Andersen's fairytale 'The Emperor's New Clothes', the child (or amateur) is able to both ask stupid questions and to ask real simple and obvious questions that the grownups (or experts) have learnt not to ask. This means it could both (either) be stupid or revealing. I don't really care which of them it is, as I want to get to the answers, and then questions are the obvious tool. So this topic really begs the question!  ;D]
Title: Re: Stupid Questions :o
Post by: crandles on December 12, 2014, 12:36:13 AM
Says it all really. You haven't a clue about the vast majority of the heat built up over summer being vented to atmosphere and space.

Yet
I understand CR has a blog post with a theory. That doesn't mean it's correct or that all math tools immediately stop giving meaningful results. I, for one, don't think CR is correct about the Arctic sea ice collapse. I think others have a better understanding of the forces at play here.

I don't see any reason not to interpret this as

I haven't a clue but I know I am right and he is wrong and I have no interest in learning why I am wrong.

Perhaps if it was just once, I ought to be more forgiving but when you do it repeatedly then it is way past time for me to give up on you unless you learn to have lot more humility.
Title: Re: Stupid Questions :o
Post by: viddaloo on December 12, 2014, 01:10:43 AM
I think playing with completely open cards and asking in the 'Stupid Questions' thread is quite humble, and I'm looking forward to all the good answers during the coming weeks.

I also think the question is a bit more complicated than melting always being bad for the melt. Perhaps it's bad for melt part of the time, but not always? In any case, it seems reaching zero ice at least till now has served to make the collapse graph steeper. Maybe that could change in the future?
Title: Re: Stupid Questions :o
Post by: LRC1962 on December 12, 2014, 02:03:41 AM
Second (and this was the part that I found a bit surprising), the distribution of the cooling across the year was also not evenly distributed: the winters over much of the norther hemisphere were actually a bit warmer than current averages. I always thought of the ice age as unimaginably cold. But over much of the north it may have been a bit warmer (but longer) than what we experience in MN. All you need to freeze things is for temps to be generally below 0 C enough of the time that warming spells don't totally thaw it.
As I used to live in the Maritime Provinces of Canada it would be somewhat obvious. The biggest snowfalls almost always come when the temp is above -10C. You can get snowstorms that come below that, but rarely below -20C. Any storms that do come below -10C the flacks tend to be very small and accumulations very low. I can not tell you the whys of it as I have never studied it, but I do know that is what happens. That is part 1 of why you would have mile high glaciers. Part 2 would be very cold summers. So let us imagine that you would have a large polar low sitting over most of NA during the summer, but in the winter you got warm moist high coming up from the south with the jet stream bringing systems across from the pacific getting cooled of by the Arctic around the 40-45 latitudes. This would give you lots of big snowstorms and at the same time keep the temps in the summer cold enough that there would be limited snow melt. The other point is the the equatorial lat. would have be warm in order to get enough moisture up into those lat.
With the jetstream running that far south the Arctic could on average have been warmer as you would need warm systems in the Arctic to push the cold down to those lat.
Could have my physics entirely wrong but I do think that would be how things would work out.
Title: Re: Stupid Questions :o
Post by: icefest on March 18, 2015, 12:55:54 PM
Another stupid question:

Does anyone know what happened to the sea ice extent chart from uaf?

http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm (http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm)
Title: Re: Stupid Questions :o
Post by: crandles on March 18, 2015, 01:10:28 PM
Can you find it from

https://ads.nipr.ac.jp/vishop/vishop-monitor.html?N ?

If not do you have an example of what it looked like?
Title: Re: Stupid Questions :o
Post by: icefest on March 18, 2015, 02:40:09 PM
Thanks crandles.
This was the closest, and I'll guess it'll be my go-to replacement:
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fpuu.sh%2FgFmxD%2F106195e10f.png&hash=dbfbeadab6bafeca0ca1fb23d835dbca)
Title: Re: Stupid Questions :o
Post by: crandles on March 18, 2015, 02:48:00 PM
Thanks crandles.
This was the closest, and I'll guess it'll be my go-to replacement:

There is a button that shows each year since 2000 (which is actually 2002 onwards) just below that chart either grey or pink depending which is selected if that helps any further.
Title: Re: Stupid Questions :o
Post by: ktonine on March 18, 2015, 09:38:22 PM
Wili --For glaciers to form you need snow to accumulate year-to-year. Summers have to be relatively short, and/or cool enough that not all the snow melts. And as LRC points out, there is a sweetspot for snow.  Nate Silver ran the data for NY (http://fivethirtyeight.com/features/big-blizzards-have-become-more-common-in-new-york/) and it was between 20 and 32F.

There is, as you note, a surprisingly small difference in *global* temperatures between glacials and interglacials.  When we consider that the changes are not uniform, and that we only need summers to be cool enough to leave a little snow left over from what fell that winter, 6 degrees C *globally* is more than enough to see glaciers in NY city - though I'm sure it would take thousands - tens of thousands - of years to reach thickness approaching a mile.
Title: Re: Stupid Questions :o
Post by: cats on March 19, 2015, 12:40:41 AM
Besides the more interactive one that crandles posted, there is also this chart - https://ads.nipr.ac.jp/vishop/data/graph/Sea_Ice_Extent_N_prev_v2_L.png
Title: Re: Stupid Questions :o
Post by: opensheart on March 19, 2015, 04:06:11 PM
Could someone post a good explanation of the following to the glossary thread in the forum.
     NSIDC
     JAXA
     CT – Cryosphere Today
Like similarities and differences, how they are computed, what they mean, who usually uses each and why?

NSIDC is referenced in the glossary, but not really defined.
I’m not finding JAXA in there at all
And CT is just defined as Cryosphere Today.

I’m looking for more than just the organization each come from.   When people use these names, they are usually referring to a specific measurement.   So these acronyms come to mean more than just an organization.   They seem to mean a specific kind of measurement done a specific way.   And there seems to be an unspoken assumption that each is to be understood to mean something different.   

Like I usually assume people are talking about NSIDC ‘extent’ graph when they reference NSIDC.   But for some reason, I usually assume people are talking about some kind of ‘area’ measurement when they talk about CT.   But I have followed this blog for a long time and have no idea what JAXA means.

I think a glossary entry defining in one place, the different kinds of measurements people refer to could be helpful.
Title: Re: Stupid Questions :o
Post by: icefest on March 20, 2015, 04:49:33 AM
Besides the more interactive one that crandles posted, there is also this chart - https://ads.nipr.ac.jp/vishop/data/graph/Sea_Ice_Extent_N_prev_v2_L.png
That's exactly the one I was looking for!
Title: Re: Stupid Questions :o
Post by: icefest on March 20, 2015, 04:56:54 AM
Continuing with the silly questions:
Would it be possible to use heat flux to measure comparative ice thicknesses?
I'm assuming not, because when ice is thicker than 50cm the instrument error would be greater than the actual surface temperature.
Title: Re: Stupid Questions :o
Post by: LRC1962 on March 26, 2015, 03:48:31 PM
I have a question. When scientist project into the future they seem to have no trouble using curved graphes, yet when drawing real time trends such as temp changes or ASI it seems that the majority draw straight lines even though it is obvious that a curve would be a better choice. Is that so any future erratic shifts can still fit within the 2 sigma?
Title: Re: Stupid Questions :o
Post by: crandles on March 26, 2015, 04:17:52 PM
Projecting curves is difficult because there are any number of curves that can fit the data very well but the projections from different types of curve can be very different. So you have to know the science very well to know what curve type to use for an extrapolation.

Where you see curved projections they are based on assumptions that are then processed to produce the projections and almost never do you see extrapolation of data with anything other than a straight line. (Mores law sees likes a curved projection from data but it is really a straight line extrapolation of data on a log scale graph.)
Title: Re: Stupid Questions :o
Post by: slow wing on March 27, 2015, 10:46:54 AM
There are reports of the Gulf Stream already slowing down:
http://icelandreview.com/news/2015/03/25/nature-gulf-stream-slows-down-impacting-iceland (http://icelandreview.com/news/2015/03/25/nature-gulf-stream-slows-down-impacting-iceland)

Could this already be lessening the transport of heat to the Arctic sea ice and therefore lessen the melt for this, and future, melt seasons?

Thanks.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on March 27, 2015, 11:55:21 AM
There are reports of the Gulf Stream already slowing down:
http://icelandreview.com/news/2015/03/25/nature-gulf-stream-slows-down-impacting-iceland (http://icelandreview.com/news/2015/03/25/nature-gulf-stream-slows-down-impacting-iceland)

Could this already be lessening the transport of heat to the Arctic sea ice and therefore lessen the melt for this, and future, melt seasons?

Thanks.
My guess here:
nope. shifts the bulk of the melt on the Pacific side. Sets a permanent Icelandic low southside of it. Throws the NA drift to Bay of Biscay, wherefrom rounds Bretagne, hits Arctic later than previously, maybe slightly cooler. Increases atmospheric heat transport both in the Pacific side and over Europe. Keeps the Atlantic coast slightly cooler, but the effect is very small. Not going to bet on this one.
Title: Re: Stupid Questions :o
Post by: johnm33 on March 27, 2015, 06:51:46 PM
There are reports of the Gulf Stream already slowing down:
http://icelandreview.com/news/2015/03/25/nature-gulf-stream-slows-down-impacting-iceland (http://icelandreview.com/news/2015/03/25/nature-gulf-stream-slows-down-impacting-iceland)

Could this already be lessening the transport of heat to the Arctic sea ice and therefore lessen the melt for this, and future, melt seasons?

Thanks.
Follow the various links here http://www.rapid.ac.uk/rapidmoc/ (http://www.rapid.ac.uk/rapidmoc/) for more info.
My take on this 1, the cold area suppresses the northward flow, which will pass beneath it. 2, suppressed flow runs the risk of releasing a torrent of basal arctic water through Fram at some critical threshold.[To be replaced from the Pacific?] 3 Retained water heats up creating an enlarged differential between the Gulf/eastern seaboard and North Atlantic [and North America]= storms. 4, Cool [wet?] growing season in Europe.
If you stop this animation and click through it you'll see that despite the cold anomoly there's still a warm anomoly stretching around Norway into the Arctic.
http://www.esrl.noaa.gov/psd/map/clim/sst.anom.anim.year.html (http://www.esrl.noaa.gov/psd/map/clim/sst.anom.anim.year.html)
Title: Re: Stupid Questions :o
Post by: Chuck Yokota on April 08, 2015, 03:44:48 PM
Has there been a discussion here on the forum about the stability of the halocline (that keeps a cap of colder and fresher water over the warmer and saltier deep waters) and how it might be affected by declining sea ice? Or could someone provide links to information on this topic?
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on May 12, 2015, 01:48:07 PM
I also wonder about the mixing out of the Halocline that open water has led to?

Currently I'm also troubled by finding dats on the influx of Pacific water through Bering? Anyone got any idea of recent temps and amounts of the inflow since we saw the triple R form and 'The Blob' develop?

If we have the Beaufort Gyre with Atlantic and Pacific waters stacked on top of each other what happens if the waters bodies near parity in temp/salinity? Do they mix out?

As it is we must be seeing some quite warm water flowing into the basin via 'the blob' and this appears set to continue as the blob is reinforced by the waters of the latest Kelvin Wave ( surfacing at the Americas currently) as it flows north to join with 'the blob'.

We have seen the impacts of warm Atlantic inflow into the Barentsz area drove so could we expect this , and next?, years ice in Beaufort to suffer more aggressive basal melt?
Title: Re: Stupid Questions :o
Post by: Jim Hunt on May 12, 2015, 04:32:54 PM
Is this any help?

http://www.whoi.edu/fileserver.do?id=92424&pt=2&p=44107 (http://www.whoi.edu/fileserver.do?id=92424&pt=2&p=44107)

Or the second image here?

http://forum.arctic-sea-ice.net/index.php/topic,1149.msg50072.html#msg50072 (http://forum.arctic-sea-ice.net/index.php/topic,1149.msg50072.html#msg50072)
Title: Re: Stupid Questions :o
Post by: Bruce Steele on May 12, 2015, 05:03:32 PM
Grey-Wolf, There are active ITP Buoys that profile salinity and temperature profiles across the arctic.
Buoy # 78 is currently positioned to get some idea about Pacific warm water and mixing as it enters the Beaufort Gyre. You can monitor changes as the season proceeds but after watching for a couple years I haven't ever seen upwelling or mixing completely break down the surface freshwater. You need to watch both salinity and temperature to spot any major upwelling events that may ( in the future ) break the surface. The strength of the Beaufort Gyre determines whether the surface fresh water says in the Canadian Basin or more quickly moves towards the exit into the Atlantic.
 Here is a paper that better describes the part the Beaufort Gyre plays.

  http://www.whoi.edu/fileserver.do?id=94184&pt=10&p=25592 (http://www.whoi.edu/fileserver.do?id=94184&pt=10&p=25592)
 
I am interested in the same type of questions you are asking re. mixing of water masses and the info

at ITP WHOI is the only real time info I can find.  The support documents posted there are all a good
 
read.    Looks like Jim beat me to it.
Title: Re: Stupid Questions :o
Post by: Anne on May 20, 2015, 10:57:51 AM
I recall reading that melt ponds are fairly stable, for when a small crack penetrates an ice floe under a melt pond, the fresh water will freeze upon reaching the cold (-1.7C) sea water (if not before), sealing the crack.
It didn't happen with the "North Pool" in 2013, though. See for example
http://forum.arctic-sea-ice.net/index.php/topic,418.msg11196.html#msg11196 (http://forum.arctic-sea-ice.net/index.php/topic,418.msg11196.html#msg11196) (where there was discussion of melt ponds wrt CT area). Presumably the sea water temperature then was warmer than -1.7C? There must be a record somewhere, other people will know.

Is there a separate thread on sea ice melt ponds, and if not, should there be?
Title: Re: Stupid Questions :o
Post by: Anne on May 21, 2015, 05:33:57 AM
Thanks, guys, I've just seen the melt ponds thread.
Title: Re: Stupid Questions :o
Post by: anotheramethyst on June 25, 2015, 10:34:42 AM
can someone please help me understand this?

i know some of you prefer the temperature anonaly maps, but i have a terribly hard time understanding them.  how exactly are they calculated? like for example, do they average all the temperatures for a given location (say san antonio) and day (say christmas) over a time span (like 1980-2000).... so hypothetically maybe they come up with 37 F as an average temp for christmas in san antonio.  so is there a range thats considered "normal" before the anomaly is calculated?  like if its 40 F in san antonio on christmas is that an anomaly of + 3? and isnt that extremely normal?  or do they calculate a normal temperature range and measure an anomaly after say it falls outside of 35-40 F? 

i guess what i'm asking is how can you tell if an anomaly is normal?  weather fluctuates all the time.  how can you tell if the temperature is significantly abnormal? 
Title: Re: Stupid Questions :o
Post by: plinius on June 25, 2015, 10:41:31 AM
Anomaly = simple deviation from the mean of some standard climate period. Differs from product to product, i.e. sometimes 1950-1980, 1960-90 or 1980-2010.
No. there are no "standard regions", otherwise your map would be biased as end product.
No, that would also not be sensible at all, since the dispersion of values varies.
And yes, one can tell significantly abnormal: experience, past dispersion/variance of values.
Title: Re: Stupid Questions :o
Post by: johnm33 on June 25, 2015, 10:45:59 AM
Check out http://ocean.dmi.dk/satellite/info.uk.html (http://ocean.dmi.dk/satellite/info.uk.html)
Title: Re: Stupid Questions :o
Post by: anotheramethyst on June 26, 2015, 12:13:15 AM
awesome thanks!!!
Title: Re: Stupid Questions :o
Post by: plinius on June 30, 2015, 04:04:54 PM
To add a stupid question by my side:
Lake ice vs. Sea ice & melt ponds:

From naive looking at satellite data I have the impression that lakes adjacent to sea ice show by far less water on the surface, i.e. less melt ponds.  Why exactly is that the case?

The only thing coming to my mind would be that on sea ice, the quite sweet water in the ponds contrasts with the salty ocean forced to a temperature of around -2C at the boundary. So, any cracks in sea ice get sealed by refreezing of pond water when it runs through the lower part of the ice floe, while the lake ice ponds just drain freely. Is that correct?
Title: Re: Stupid Questions :o
Post by: Paddy on July 04, 2015, 10:53:04 AM
Stupid question: are the forest fires in Alaska and Canada (http://www.weather.com/news/news/canada-alaska-wildfire-smoke-midwest-south-east-july-2015-20150702) likely to impact sea ice melt at all, and which way is most of the smoke, heat, ash etc being carried by the prevailing winds?
Title: Re: Stupid Questions :o
Post by: wanderer on July 10, 2015, 07:48:22 PM
Where do I find the exact area numbers of those regions:
https://14adebb0-a-62cb3a1a-s-sites.googlegroups.com/site/arctischepinguin/home/amsr2/grf/amsr2-area-regional.png?attachauth=ANoY7crVzMfAIAIuf50OzbgJN9F6uC11gm087Kw92e2gLTTWpdydLAq0iwdnyQubK3n8K-8wjonWESSKKjez5HyiYz38wgKdRiSIAYbxC9qr9TsojKbPv_sVNIMc98IEi78EdK-DZ4YeJyKNfRTgUn-2kZhKBx2BIpfCdpwW3FVLf6RDzmRDfIv433GktVJz5busYeFuPdAhx275xSfS7Fe6rXQyprF1fenhypHBt_PtxUlFyKbbjW3LuxEqH3x4-9yQSbUSu5Tl&attredirects=0

Would be great to compare 2015 to 2012, especially when ignoring some regions like Baffin and Hudson
Title: Re: Stupid Questions :o
Post by: oren on July 12, 2015, 11:43:39 AM
Has anyone seen this? Any idea about credibility (or I guess lack thereof)?

Is a mini ICE AGE on the way? Scientists warn the sun will 'go to sleep' in 2030 and could cause temperatures to plummet

http://www.dailymail.co.uk/sciencetech/article-3156594/Is-mini-ICE-AGE-way-Scientists-warn-sun-sleep-2020-cause-temperatures-plummet.html (http://www.dailymail.co.uk/sciencetech/article-3156594/Is-mini-ICE-AGE-way-Scientists-warn-sun-sleep-2020-cause-temperatures-plummet.html)
Title: Re: Stupid Questions :o
Post by: misanthroptimist on July 12, 2015, 01:16:04 PM
Has anyone seen this? Any idea about credibility (or I guess lack thereof)?

Is a mini ICE AGE on the way? Scientists warn the sun will 'go to sleep' in 2030 and could cause temperatures to plummet

http://www.dailymail.co.uk/sciencetech/article-3156594/Is-mini-ICE-AGE-way-Scientists-warn-sun-sleep-2020-cause-temperatures-plummet.html (http://www.dailymail.co.uk/sciencetech/article-3156594/Is-mini-ICE-AGE-way-Scientists-warn-sun-sleep-2020-cause-temperatures-plummet.html)
No credibility whatsoever. https://www.skepticalscience.com/grand-solar-minimum-barely-dent-AGW.html (https://www.skepticalscience.com/grand-solar-minimum-barely-dent-AGW.html)
Title: Re: Stupid Questions :o
Post by: Wipneus on July 12, 2015, 01:37:44 PM
Where do I find the exact area numbers of those regions:
https://14adebb0-a-62cb3a1a-s-sites.googlegroups.com/site/arctischepinguin/home/amsr2/grf/amsr2-area-regional.png?attachauth=ANoY7crVzMfAIAIuf50OzbgJN9F6uC11gm087Kw92e2gLTTWpdydLAq0iwdnyQubK3n8K-8wjonWESSKKjez5HyiYz38wgKdRiSIAYbxC9qr9TsojKbPv_sVNIMc98IEi78EdK-DZ4YeJyKNfRTgUn-2kZhKBx2BIpfCdpwW3FVLf6RDzmRDfIv433GktVJz5busYeFuPdAhx275xSfS7Fe6rXQyprF1fenhypHBt_PtxUlFyKbbjW3LuxEqH3x4-9yQSbUSu5Tl&attredirects=0

Would be great to compare 2015 to 2012, especially when ignoring some regions like Baffin and Hudson


wanderer, the UH AMSR2 data exist only for 2013 and later. For 2012 I use SSMIS data that in the overlapping period is reasonable similar to the AMSR2  version.

It seems we are looking at the same thing. I have therefore a combined data set, consisting of just the Basin regions with 2012-SSMIS data, followed by the AMSR2 data. Find it here:

https://sites.google.com/site/arctischepinguin/home/amsr2/data/UH_AMSR2_3.125km_basin.areaextent.txt

(in the same directory are the full UH AMSR2 data and the Jaxa data)

Success!
Title: Re: Stupid Questions :o
Post by: seaicesailor on July 12, 2015, 02:20:34 PM
Has anyone seen this? Any idea about credibility (or I guess lack thereof)?

Is a mini ICE AGE on the way? Scientists warn the sun will 'go to sleep' in 2030 and could cause temperatures to plummet

http://www.dailymail.co.uk/sciencetech/article-3156594/Is-mini-ICE-AGE-way-Scientists-warn-sun-sleep-2020-cause-temperatures-plummet.html (http://www.dailymail.co.uk/sciencetech/article-3156594/Is-mini-ICE-AGE-way-Scientists-warn-sun-sleep-2020-cause-temperatures-plummet.html)

This paper looks likes one of those supermarket cashier magazines, an alien abducted Jenny Lo and got her pregnant, and stuff like that
Title: Re: Stupid Questions :o
Post by: pikaia on July 12, 2015, 03:30:33 PM
Has anyone seen this? Any idea about credibility (or I guess lack thereof)?

Is a mini ICE AGE on the way? Scientists warn the sun will 'go to sleep' in 2030 and could cause temperatures to plummet
http://blog.hotwhopper.com/2015/07/theres-only-two-year-reprieve-if-sun.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+hotwhopper%2FSJtd+%28HotWhopper%29 (http://blog.hotwhopper.com/2015/07/theres-only-two-year-reprieve-if-sun.html?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+hotwhopper%2FSJtd+%28HotWhopper%29)

"To sum up, if the sun fades over the next few years, it won't stop global warming. It will likely make a difference at the local level. In the northern hemisphere changes may be linked with changes in the North Atlantic (and possibly the Pacific)."



Title: Re: Stupid Questions :o
Post by: Jim Hunt on July 12, 2015, 03:56:12 PM
Has anyone seen this? Any idea about credibility (or I guess lack thereof)?

For my views on the credibility of The Daily Mail please feel free to peruse:

http://GreatWhiteCon.info/tag/daily-mail/ (http://GreatWhiteCon.info/tag/daily-mail/)

Quote
The evidence suggests that David Rose doesn’t research his sources properly, doesn’t understand English and doesn’t understand common mathematical symbols.  Alternatively he understands all of that perfectly well, but chooses to misrepresent all of that to his loyal readership instead of educating them about the facts of the matter.
Title: Re: Stupid Questions :o
Post by: oren on July 12, 2015, 04:14:37 PM
Thanks all!
Title: Re: Stupid Questions :o
Post by: Jim Pettit on July 12, 2015, 04:31:34 PM
Has anyone seen this? Any idea about credibility (or I guess lack thereof)?

Is a mini ICE AGE on the way? Scientists warn the sun will 'go to sleep' in 2030 and could cause temperatures to plummet

http://www.dailymail.co.uk/sciencetech/article-3156594/Is-mini-ICE-AGE-way-Scientists-warn-sun-sleep-2020-cause-temperatures-plummet.html (http://www.dailymail.co.uk/sciencetech/article-3156594/Is-mini-ICE-AGE-way-Scientists-warn-sun-sleep-2020-cause-temperatures-plummet.html)
Here's a concatenated series of tweets from Gavin Schmidt's (@ClimateOfGavin (http://Gavin Schmidt (Director of NASA's Goddard Institute for Space Studies))) Twitter feed:

"A period in the late 17th C (the "Maunder minimum") had very few sunspots, smaller amplitude 11-yr cycles & perhaps reduced irradiance. Combined with an increase in volcanic activity, these natural drivers are implicated in the relative coolness of the 'Little Ice Age'. The result being discussed is a statistical prediction of a '60%' reduction in the magnitude of the next few solar cycles. For context, climate forcing over a solar cycle is about 0.175 W/m2. Current forcing from CO2 is more than 10 times larger. 60% reduction in solar cycle magnitude wld be a climate forcing of -0.1 W/m2. Equivalent to a decrease of 8ppm CO2 (~3 years worth). Thus, at max, the predicted solar cycle change will slow GW by about a few years, and has no chance of causing a 'mini ice age'."

(Bolding mine.)
Title: Re: Stupid Questions :o
Post by: DavidR on July 12, 2015, 04:43:07 PM
Has anyone seen this? Any idea about credibility (or I guess lack thereof)?

Is a mini ICE AGE on the way? Scientists warn the sun will 'go to sleep' in 2030 and could cause temperatures to plummet

http://www.dailymail.co.uk/sciencetech/article-3156594/Is-mini-ICE-AGE-way-Scientists-warn-sun-sleep-2020-cause-temperatures-plummet.html (http://www.dailymail.co.uk/sciencetech/article-3156594/Is-mini-ICE-AGE-way-Scientists-warn-sun-sleep-2020-cause-temperatures-plummet.html)
Here's a concatenated series of tweets from Gavin Schmidt's (@ClimateOfGavin (http://Gavin Schmidt (Director of NASA's Goddard Institute for Space Studies))) Twitter feed:

"A period in the late 17th C (the "Maunder minimum") had very few sunspots, smaller amplitude 11-yr cycles & perhaps reduced irradiance. Combined with an increase in volcanic activity, these natural drivers are implicated in the relative coolness of the 'Little Ice Age'. The result being discussed is a statistical prediction of a '60%' reduction in the magnitude of the next few solar cycles. For context, climate forcing over a solar cycle is about 0.175 W/m2. Current forcing from CO2 is more than 10 times larger. 60% reduction in solar cycle magnitude wld be a climate forcing of -0.1 W/m2. Equivalent to a decrease of 8ppm CO2 (~3 years worth). Thus, at max, the predicted solar cycle change will slow GW by about a few years, and has no chance of causing a 'mini ice age'."

(Bolding mine.)
A good way of viewing global warming is to look at the temperatures during  solar minimums. Solar maximums can increase temperatures up to about  0.3 degrees C. However these have no effect on minimums. So if you plot the minimums as a measure of increase you will see a clearly rising pattern of more than 0.1 deg centigrade per cycle. This decade has seen a low solar maximum so it is unlikely we will see a decline in temperatures as we did last decade. This decade will probably  be the first decade in recorded history with no  five year trend of declining temperatures
Title: Re: Stupid Questions :o
Post by: Metamemesis on July 13, 2015, 05:19:53 PM
Stupid questions:

1) What resolution are the EOSDIS WorldView images?*
2) Are they better or worse than 3-5 meter resolution?
3) Would there be any interest in, or practical use use for, forum members in obtaining 3-5 meter resolution images of the Arctic Sea Ice?

* i.e. https://earthdata.nasa.gov/labs/worldview/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor%28hidden%29,MODIS_Terra_CorrectedReflectance_TrueColor,Coastlines&t=2015-07-13&v=-3595273.3764701397,-1177313.5812421292,4269046.623529861,2685214.418757871 (https://earthdata.nasa.gov/labs/worldview/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor%28hidden%29,MODIS_Terra_CorrectedReflectance_TrueColor,Coastlines&t=2015-07-13&v=-3595273.3764701397,-1177313.5812421292,4269046.623529861,2685214.418757871)
Title: Re: Stupid Questions :o
Post by: jdallen on July 13, 2015, 05:26:29 PM
Stupid questions:

1) What resolution are the EOSDIS WorldView images?*
2) Are they better or worse than 3-5 meter resolution?
3) Would there be any interest in, or practical use use for, forum members in obtaining 3-5 meter resolution images of the Arctic Sea Ice?

* i.e. https://earthdata.nasa.gov/labs/worldview/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor%28hidden%29,MODIS_Terra_CorrectedReflectance_TrueColor,Coastlines&t=2015-07-13&v=-3595273.3764701397,-1177313.5812421292,4269046.623529861,2685214.418757871 (https://earthdata.nasa.gov/labs/worldview/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor%28hidden%29,MODIS_Terra_CorrectedReflectance_TrueColor,Coastlines&t=2015-07-13&v=-3595273.3764701397,-1177313.5812421292,4269046.623529861,2685214.418757871)

As I recall, EOSDIS Worldview minimum resolution is 250 meters.
Title: Re: Stupid Questions :o
Post by: Laurent on July 13, 2015, 05:37:01 PM
I am not sure but I think Sentinel satellites have 15m resolution.
http://www.polarview.aq/arctic (http://www.polarview.aq/arctic)
But I don't think we need them so much (we, amateurs), there is the buoys to give as an idea of the quality of the ice.
Title: Re: Stupid Questions :o
Post by: Peter Ellis on July 13, 2015, 05:47:52 PM
Interest?  Probably.
Practical use for?  Minimal.
Ability to obtain?  Non-existant.
Title: Re: Stupid Questions :o
Post by: ktonine on July 13, 2015, 06:00:23 PM
Interest?  Probably.
Practical use for?  Minimal.
Ability to obtain?  Non-existant.

Peter, non-existant? Naw, you're just getting old :)

The current commercial satellite packages offer resolutions of less than .5m. 

See wikipedia for a quick rundown of what's availavble.  https://en.wikipedia.org/wiki/Satellite_imagery

Of course it would be great to have them, but the cost is pretty exorbitant (sic).

Title: Re: Stupid Questions :o
Post by: Metamemesis on July 13, 2015, 06:08:01 PM

Of course it would be great to have them, but the cost is pretty exorbitant (sic).

You'd be surprised. https://www.planet.com/ (https://www.planet.com/)

The CEO, Will Marshall, is planning on making much of the data and imagery open-source and freely available.
Title: Re: Stupid Questions :o
Post by: Nick_Naylor on July 13, 2015, 10:23:39 PM

3) Would there be any interest in, or practical use use for, forum members in obtaining 3-5 meter resolution images of the Arctic Sea Ice?


If you find it, we will discuss. It might be TMI for many/most purposes, but super-hi-res images would undoubtedly be helpful when something is interesting but too small to see in the standard ones.
Title: Re: Stupid Questions :o
Post by: oren on July 13, 2015, 10:57:35 PM
Stupid questions:

3) Would there be any interest in, or practical use use for, forum members in obtaining 3-5 meter resolution images of the Arctic Sea Ice?

Well of course, lots of interest and I'm sure many practical uses. But how does one obtain such images?
Title: Re: Stupid Questions :o
Post by: slow wing on July 14, 2015, 07:37:48 AM
Metre-scale resolutions over the Arctic ice would presumably be very valuable to scientists.

One obvious application would be surveying & measuring iceberg size distributions throughout the ice pack.
Title: Re: Stupid Questions :o
Post by: Tor Bejnar on July 14, 2015, 03:45:39 PM
Icebergs (https://en.wikipedia.org/wiki/Iceberg) are from glaciers or ice shelves.  Functionally all the ice we see in the Arctic Ocean is in ice floes (https://en.wikipedia.org/wiki/Ice_floe).  There will be a few icebergs in Nares Strait, Baffin Bay and Greenland Sea (from Greenland glaciers), and probably some in the Canadian Arctic Archipelago (CAA).  I understand virtually all the ice shelves (https://en.wikipedia.org/wiki/Ice_shelf) on the north side of Elsmere Island are gone.
Title: Re: Stupid Questions :o
Post by: Vergent on July 14, 2015, 04:45:29 PM
Stupid questions:

3) Would there be any interest in, or practical use use for, forum members in obtaining 3-5 meter resolution images of the Arctic Sea Ice?

Well of course, lots of interest and I'm sure many practical uses. But how does one obtain such images?

Google Earth's android app is now giving 10 cm resolution images..........Further, they are rendering them into psudo-3D!!?? Here are 2 views of the same A380 at LAX.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2F8IIEMfP.jpg&hash=e314d025c6fc2af291a88658435f98ea)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi.imgur.com%2FNZaRLCj.jpg&hash=85befff57a4351b79e704d3fe1f2af08)

3D image splicing issues are apparent, But wow, how do they do it? I can pan around and see all 4 sides of my house. Unfortunately, they do not do ice. Maybe, if we asked very nicely...................
Title: Re: Stupid Questions :o
Post by: Bob Wallace on July 14, 2015, 06:18:18 PM
Not sure the question is stupid, but I'm putting it here in the event that it's been answered several times before and I've missed it.

Why is the CAA so resistant to melt?  Is it trapped multi-year ice which has no opportunity to open up the water for direct heating by moving around as old ice does in other regions?
Title: Re: Stupid Questions :o
Post by: Rick Aster on July 14, 2015, 06:51:29 PM
My impression on the northernmost channels in Canada is that it is not just stuck ice, but some of the thickest ice in the Arctic. Thick ice was a permanent feature in a broad area northwest of Greenland and the Canadian Arctic Archipelago until a few years ago, and it seems like there is still some of this thick ice hanging around. Two factors that partially explain the thicker ice: the coastline makes it easy for ice to form in the early fall by giving ice a place to stick, and ice pushed against the coast can pile up to form thicker ice.
Title: Re: Stupid Questions :o
Post by: ghoti on July 14, 2015, 07:22:49 PM
I think that the northern most channels have a lot of ice imported. The WWF has a program called The Last Ice based in that area. Their idea is the last ice will be there when more southern ice disappears because of the import from the central basin.
Title: Re: Stupid Questions :o
Post by: Bob Wallace on July 15, 2015, 04:04:12 AM
I think that the northern most channels have a lot of ice imported. The WWF has a program called The Last Ice based in that area. Their idea is the last ice will be there when more southern ice disappears because of the import from the central basin.

So the ice in those channels is Arctic foie gras?  I can see that. 
Title: Re: Stupid Questions :o
Post by: Daniel B. on July 15, 2015, 04:25:14 PM
The Royal Astronomical society is hardly tabloid material.

http://www.ras.org.uk/news-and-press/2680-irregular-heartbeat-of-the-sun-driven-by-double-dynamo (http://www.ras.org.uk/news-and-press/2680-irregular-heartbeat-of-the-sun-driven-by-double-dynamo)
Title: Re: Stupid Questions :o
Post by: oren on July 15, 2015, 06:06:53 PM
The Royal Astronomical society is hardly tabloid material.

http://www.ras.org.uk/news-and-press/2680-irregular-heartbeat-of-the-sun-driven-by-double-dynamo (http://www.ras.org.uk/news-and-press/2680-irregular-heartbeat-of-the-sun-driven-by-double-dynamo)

As I understand it, unscientifically speaking, the main criticism is not that the Maunder minimum can't happen as predicted, but that its effect on global temperatures will not cause a mini ice age or anything of the sort, instead causing only a small bump in the temp charts.
Title: Re: Stupid Questions :o
Post by: jdallen on July 15, 2015, 06:14:30 PM
The Royal Astronomical society is hardly tabloid material.

http://www.ras.org.uk/news-and-press/2680-irregular-heartbeat-of-the-sun-driven-by-double-dynamo (http://www.ras.org.uk/news-and-press/2680-irregular-heartbeat-of-the-sun-driven-by-double-dynamo)
No, but it's utility depends on how you intend to use the references it provides. Zarkhova's paper has been disingenuously and ignorantly misinterpreted by a small herd of tabloids and AGW "denialist" sites. It gets worse, as they also misinterprete what actually took place during the Maunder Minimum.

The paper she published implies insulation *might* decrease by 1/10th of 1% - which is less than the increase caused by human sourced GHG's. It may not decrease that much nor will it stay down.

So what is your question?

Title: Re: Stupid Questions :o
Post by: DavidR on July 16, 2015, 12:48:55 AM
The Royal Astronomical society is hardly tabloid material.

http://www.ras.org.uk/news-and-press/2680-irregular-heartbeat-of-the-sun-driven-by-double-dynamo (http://www.ras.org.uk/news-and-press/2680-irregular-heartbeat-of-the-sun-driven-by-double-dynamo)
No, but it's utility depends on how you intend to use the references it provides. Zarkhova's paper has been disingenuously and ignorantly misinterpreted by a small herd of tabloids and AGW "denialist" sites. It gets worse, as they also misinterprete what actually took place during the Maunder Minimum.

The paper she published implies insulation *might* decrease by 1/10th of 1% - which is less than the increase caused by human sourced GHG's. It may not decrease that much nor will it stay down.

So what is your question?
If this prediction holds it will  remove one of the main cause of fluctuation in global temperatures for about the next 40 years.  Global temperatures will continue to rise but there will be no long term declines that  we typically see as the sunspot count  returns to a minimum.  Most decades show several years of reduced temperatures after the solar maximum however with no significant maximums there will be no significant declines.  We won't see another so - called 'hiatus' for  decades.
Title: Re: Stupid Questions :o
Post by: Rick Aster on July 16, 2015, 01:49:53 AM
The Royal Astronomical society is hardly tabloid material.

http://www.ras.org.uk/news-and-press/2680-irregular-heartbeat-of-the-sun-driven-by-double-dynamo (http://www.ras.org.uk/news-and-press/2680-irregular-heartbeat-of-the-sun-driven-by-double-dynamo)
No, but it's utility depends on how you intend to use the references it provides. Zarkhova's paper has been disingenuously and ignorantly misinterpreted by a small herd of tabloids and AGW "denialist" sites. It gets worse, as they also misinterprete what actually took place during the Maunder Minimum.

The paper she published implies insulation *might* decrease by 1/10th of 1% - which is less than the increase caused by human sourced GHG's. It may not decrease that much nor will it stay down.

So what is your question?

I am afraid many readers (of the news stories) could be confused by the "60% reduction." Some of the news stories try to make you think the sun will be 60% less bright for a decade or two, but of course that would be impossible. To be very clear about that, the difference in brightness would be so slight that it would not be detectable without carefully calibrated equipment. Another problem with the way the stories are written is that they imply the astronomers are predicting some form of an ice age, when in reality the ice age prediction was made by the so-called journalists. A third problem is that the story, despite being a fabrication, was picked up by wire services and repeated all over the place.
Title: Re: Stupid Questions :o
Post by: seaicesailor on August 01, 2015, 05:43:54 PM

Is there a reason why there aren't buoys installed at the Eurasian side of the Arctic?

Thanks.
Title: Re: Stupid Questions :o
Post by: AySz88 on August 01, 2015, 08:43:25 PM
Google Earth's android app is now giving 10 cm resolution images..........Further, they are rendering them into psudo-3D!!?? Here are 2 views of the same A380 at LAX.

(snip)

3D image splicing issues are apparent, But wow, how do they do it? I can pan around and see all 4 sides of my house. Unfortunately, they do not do ice. Maybe, if we asked very nicely...................

Although the view is called "satellite", I'm pretty sure these photos and data are taken by plane.  Maybe we can hire Santa....
Title: Re: Stupid Questions :o
Post by: anotheramethyst on August 03, 2015, 07:12:35 AM
you mean google street view?  those are actually taken from cars driving down the street. 
Title: Re: Stupid Questions :o
Post by: AySz88 on August 03, 2015, 07:20:35 AM
you mean google street view?  those are actually taken from cars driving down the street.

The example was a rendering of a plane at an airport, so I'm assuming that wasn't something accessible to cars? Unless the 3d derivation technology is a lot better than I thought.
Title: Re: Stupid Questions :o
Post by: anotheramethyst on August 03, 2015, 07:27:43 AM
oh sorry, you're probably right!!
Title: Re: Stupid Questions :o
Post by: seaicesailor on August 03, 2015, 09:12:05 AM

Is there good reasons why there aren't buoys installed at the Eurasian side of the Arctic?

I only think of the drift/melt removing them in one/two years, but that doesnt stop people putting them at the NP.

Thanks.

[/quote]
Title: Re: Stupid Questions :o
Post by: seaicesailor on August 04, 2015, 02:01:09 PM

Is there good reasons why there aren't buoys installed at the Eurasian side of the Arctic?

I only think of the drift/melt removing them in one/two years, but that doesn't stop people from putting them at the NP.

Sorry that I insist, final time I do.
Nobody knows? Is it a Russian secret thing?
 :-\

Thank you !!!  :)
Title: Re: Stupid Questions :o
Post by: oren on August 04, 2015, 05:04:16 PM

Is there good reasons why there aren't buoys installed at the Eurasian side of the Arctic?

I only think of the drift/melt removing them in one/two years, but that doesn't stop people from putting them at the NP.

Sorry that I insist, final time I do.
Nobody knows? Is it a Russian secret thing?
 :-\

Thank you !!!  :)

I took the liberty of reposting your question in the Buoys thread, someone there might come with the answer.
Title: Re: Stupid Questions :o
Post by: seaicesailor on August 04, 2015, 06:05:59 PM

Is there good reasons why there aren't buoys installed at the Eurasian side of the Arctic?

I only think of the drift/melt removing them in one/two years, but that doesn't stop people from putting them at the NP.

Sorry that I insist, final time I do.
Nobody knows? Is it a Russian secret thing?
 :-\

Thank you !!!  :)

I took the liberty of reposting your question in the Buoys thread, someone there might come with the answer.

Wow thank you man!
Title: Re: Stupid Questions :o
Post by: solartim27 on August 05, 2015, 09:55:06 PM
I would have thought this discoloration off SoCal was from smoke, but I then noticed it is seasonal, starting in early March.  Could this be sun glare on the satellite equipment or just the reflectance from the surface?  I don't think it's atmospheric, but I suppose it could be.
(There is a nice bit of smoke from the CA Rocky fire up in the corner)
Title: Re: Stupid Questions :o
Post by: Andreas T on August 05, 2015, 10:29:44 PM
If you zoom out to see the whole earth in the geographic view you see that this glare is seen when the satellite is over water at that latitude. Over the year the latitude with that glare moves from south to north of the equator and back again. It therefore is dependent on the position of the sun. If you overlay the orbital track you see that the glare is slightly to the east of the track. This is because the local time of the terra track is a little before midday. The sun which is behind the camera and to the right reflects off the water surface. The position of that glare is to the west in the aqua images which are taken after midday and change position relative to the ground on different days.
Title: Re: Stupid Questions :o
Post by: helorime on August 14, 2015, 04:55:59 PM
Why is the DMi arctic sea ice extent so much higher than everyone else's?

http://ocean.dmi.dk/arctic/icecover.uk.php (http://ocean.dmi.dk/arctic/icecover.uk.php)
Title: Re: Stupid Questions :o
Post by: seaicesailor on August 14, 2015, 08:52:00 PM
Why is the DMi arctic sea ice extent so much higher than everyone else's?

http://ocean.dmi.dk/arctic/icecover.uk.php (http://ocean.dmi.dk/arctic/icecover.uk.php)

The total area of sea ice is the sum of First Year Ice (FYI), Multi Year Ice (MYI) and the area of ambiguous ice types, from the OSISAF ice type product.

From the webpage. It includes ambiguous ice. That explains a lot, and nothing at all
Title: Re: Stupid Questions :o
Post by: Wipneus on August 15, 2015, 09:00:40 AM
Why is the DMi arctic sea ice extent so much higher than everyone else's?

http://ocean.dmi.dk/arctic/icecover.uk.php (http://ocean.dmi.dk/arctic/icecover.uk.php)

I find the graph raises a lot of questions:

Quote
The ice extent values are calculated from the ice type data from the Ocean and Sea Ice, Satellite Application Facility (OSISAF), where areas with ice concentration higher than 15% are classified as ice.

So, instead of directly using sea ice concentration, ice classification is used and they rely on a undocumented (AFAIK) feature that concentrations below 15% will be tagged as open water.

The reason why they do not use the sea ice concentration product from OSISAF is that a wide (~50km) coastal band is masked out. Due to the land spill over effect, this area would record lots of "false" ice. Calculation extent from SIC would lead to far lower values than (NSIDC, JAXA, Uni Hamburg).

There are newer experimental products that do attempt to calculate the concentration in this area. I am looking in to these an am not impressed: there is still a lot of false ice visible which may well explain why even these newer experimental products give greater total extent than other products.
Title: Re: Stupid Questions :o
Post by: SCYetti on February 14, 2016, 07:07:50 PM
I have a stupid question about the heat content of water at the freezing point. I haven't attended college so I'm going to word my question at a high school level, using grams and calories.

Water freezes at 0C. It takes about 1 calorie to raise or lower the temperature of 1 gram 1 degree C. 80 calories must be lost from a gram at 0C to change it from liquid to ice. Though the freezing point of sea water is lower I assume this is true of the Arctic Ocean as well. So my question is can we discern the actual energy content of freezing temperature water? Shouldn't we expect a pause in temperature increase as the water changes from almost freezing to almost warming?

In other words couldn't there be a large change in enthalpy without a change in temperature?
Title: Re: Stupid Questions :o
Post by: oren on February 14, 2016, 10:30:33 PM
I have a stupid question about the heat content of water at the freezing point. I haven't attended college so I'm going to word my question at a high school level, using grams and calories.

Water freezes at 0C. It takes about 1 calorie to raise or lower the temperature of 1 gram 1 degree C. 80 calories must be lost from a gram at 0C to change it from liquid to ice. Though the freezing point of sea water is lower I assume this is true of the Arctic Ocean as well. So my question is can we discern the actual energy content of freezing temperature water? Shouldn't we expect a pause in temperature increase as the water changes from almost freezing to almost warming?

In other words couldn't there be a large change in enthalpy without a change in temperature?

I can answer in two directions, let me know if it helps any (and beware as I might be wrong):
First, as you heat up 1 gram of ice with a constant supply of 1 calorie per second, you will get a temperature rise of 1 deg/sec until you hit 0deg, then for 80 sec you will get no temp rise, and then you will return to the temp rise rate of 1 deg/sec (but it won't be ice anymore of course).
Second,  if you add 40 calories to 1gr of 0deg ice, the way I understand it is you get 0.5gr ice and 0.5gr water. The energy goes into the phase change itself.
Title: Re: Stupid Questions :o
Post by: Andreas T on February 14, 2016, 11:15:42 PM
you can actually see that effect if you look at the DMI north of 80deg surface temperature graph. There is a steep temperature rise when the sun appears in spring but the those temps are stuck close to 0 deg C with 24h sunshine. Its a big ice and water mixture which won't increase its temperature until all the ice is melted, despite loads of heat energy going into it.
Title: Re: Stupid Questions :o
Post by: SCYetti on February 15, 2016, 02:33:37 PM
Oren and AndreasT thank you for your responses to my stupid question. But it is the nature of things that the difference between stupid and genius is that genius has limits. Thus I have tons more questions.

I recently set my refrigerator  to too low a setting and everything froze except the bottles of soft drinks. But when I opened a bottle it immediately filled with ice. It seemed to be more ice than could be accounted for by merely the temperature change of the expanding gas. It seems pressure can constrain freezing as it does boiling. The pressure at the depth of 10 meters, I would assume, are greater than the pressure in my drink bottle. Could the water absorb or release a great amount of latent energy without temperature change or phase change?
Title: Re: Stupid Questions :o
Post by: SteveMDFP on February 15, 2016, 03:41:03 PM
Oren and AndreasT thank you for your responses to my stupid question. But it is the nature of things that the difference between stupid and genius is that genius has limits. Thus I have tons more questions.

I recently set my refrigerator  to too low a setting and everything froze except the bottles of soft drinks. But when I opened a bottle it immediately filled with ice. It seemed to be more ice than could be accounted for by merely the temperature change of the expanding gas. It seems pressure can constrain freezing as it does boiling. The pressure at the depth of 10 meters, I would assume, are greater than the pressure in my drink bottle. Could the water absorb or release a great amount of latent energy without temperature change or phase change?

I'll chime in from a background of moderate general science literacy.  I think the soda bottle experience is only distantly related.  I suspect the answer to your final guestion (at least for a "great amount" of latent energy is "no."

What's going on with the soda bottle is not that the pressure on water molecules is preventing ice formation (much), but that the pressure on CO2 molecules is tending to force them to stay in solution, rather than bubbling out.  The physical process of ice crystal formation requires that other molecules (salt ions, sugar molecules, CO2, whatever) be forced out of the expanding crystals.  The higher the molar amount of foreign dissolved molecules, the colder the temp has to be to allow crystals to form.

Your very cold but liquid soda bottles would freeze instantly when pressure is released only because CO2 can then immediately bubble out of solution.  Instantly removed from the water, the temp at which ice can form is substantially above current temp.  If I'm correct in this thinking. a temperature reading of the new ice would be at or below 0 degrees C, but higher than the ambient temp in the refrigerator. 

A corollary to all this is that any gas is much more soluble at great ocean depth than at the surface.  This has some relevance  for climate issues with methane, which dissolves into water if released at great ocean depth, but bubbles to the surface when released from shallower waters.

Title: Re: Stupid Questions :o
Post by: Peter Ellis on February 15, 2016, 06:04:44 PM
http://www.thenakedscientists.com/HTML/experiments/exp/freezing-lemonade-bottles/ (http://www.thenakedscientists.com/HTML/experiments/exp/freezing-lemonade-bottles/)

Yes, the main effect here is that carbonated water has a freezing point lower than zero degrees.  If the bottle is then chilled to a point where ordinary water freezes, but carbonated water does not, then allowing the CO2 to escape will trigger freezing.
Title: Re: Stupid Questions :o
Post by: SCYetti on February 15, 2016, 06:48:34 PM
Please check this out
https://www.youtube.com/watch?v=3Qasw7lb2UM (https://www.youtube.com/watch?v=3Qasw7lb2UM)
Title: Re: Stupid Questions :o
Post by: Peter Ellis on February 15, 2016, 10:54:38 PM
I considered supercooling, but couldn't see any reasonable way that could affect the carbonated drinks and not the other bottles in the same fridge.
Title: Re: Stupid Questions :o
Post by: opensheart on February 18, 2016, 03:20:31 AM
I would ask a clarifying question about freezing sea water.

Most places say sea/salt water freezes at about -1.8C or -1-.9C or -2C, depending on the salinity.   

There are a couple references in this forum about air temps being -11C. 

At first I was thinking that meant you needed both,  water at least -1.8C and an air temp of -11 or below.   But I was trying to track this down and verify this.   I'm not finding this -11C mentioned other places.   Here on this blog it seems to trace back to 'wayne'.   And searching through his EH2R blog I found this quote:

Quote
sea water was so warmed air temperatures needed to be below -11 C.

Which leads me to guess this -11C number may be what is required to freeze the sea when the water temp is wamer than -1.8C.   

Can someone clarify this?

Is there some ratio here, like: salt water at temp X will need air temp of Y to freeze?
Title: Re: Stupid Questions :o
Post by: Pmt111500 on February 18, 2016, 03:37:48 AM
I would ask a clarifying question about freezing sea water.

Most places say sea/salt water freezes at about -1.8C or -1-.9C or -2C, depending on the salinity.   
O
There are a couple references in this forum about air temps being -11C.   Here on this blog it seems to trace back to 'wayne'.   And searching through his EH2R blog I found this quote:

Quote
sea water was so warmed air temperatures needed to be below -11 C.

Which leads me to guess this -11C number may be what is required to freeze the sea when the water temp is wamer than -1.8C.   

Can someone clarify this?

Is there some ratio here, like: salt water at temp X will need air temp of Y to freeze?

I'm not too sure of this, likely this is an observational measure and not derived from purely theoretical grounds. I'd imagine perfectly still sea water would indeed freeze at the -2 it's supposed to. In reality there are waves and tides mixing the uppermost layer so the surface tends to constantly be in just above the still water freezing point. -11 would then be about the air temperature needed to drain the deeper supply of heat so the surfacing waterr freezes instanly, or possibly during one night. Further clarification is probably needed for this, but this is how I see it. This would be the ocean equivalent of the effect seen in streams and rivers in which the faster running sections freeze the latest.
Title: Re: Stupid Questions :o
Post by: ecojosh on February 18, 2016, 05:13:01 AM
My experience in British Columbia is that -10 or -11c is indeed about when the sea starts to freeze over.
Title: Re: Stupid Questions :o
Post by: Andreas T on February 18, 2016, 09:16:11 PM
Something that is different between ice forming on freshwater and ice on seawater is that  saltwater is at its densest when it is at the freezing temperature, so it will sink relative to water which is even very little warmer by density driven convection. The water column (the part of it which has the same salinity as the top layer) has to reach freezing temperature before it freezes.
But the ice itself, through "freezing out" salt, is less dense than seawater. When air is much colder than the water the surface layer can cool fast enough and form ice before it is accelerated downwards (with temperature and density gradients being not too large)
https://nsidc.org/cryosphere/seaice/index.html (https://nsidc.org/cryosphere/seaice/index.html)
Once there is a layer of ice, which is cooled by cold air (and radiative cooling) a thin boundary layer at its bottom can have a temperature gradient (lowest at the ice surface) which adds further freezing to the ice bottom.
Freshwater on the other hand has its maximum density at 4 deg C so less water has to be cooled below that temperature to start freezing the top layer.
Title: Re: Stupid Questions :o
Post by: johnm33 on February 19, 2016, 01:13:50 PM
As best as I recall it wayne  commented about ice formation on the blog about three years ago, essentially saying the same as Andreas T s comment above.
My own question, IIRC sea ice travels at about 2-3% of windspeed, but given present conditions I want to know how it accelerates in persistent winds, and how winds at various speeds affect it's movement. For instance there must be some point where faster winds become detatched from the surface due to turbulence.
Title: Re: Stupid Questions :o
Post by: jai mitchell on February 22, 2016, 07:30:58 AM
My stupid question of the day:  When calculating the negative forcing associated with aerosols, are the Lapse Rate and Water Vapor feedbacks included in the total forcing effect?
Title: Re: Stupid Questions :o
Post by: Richard Rathbone on February 23, 2016, 11:54:55 AM
My stupid question of the day:  When calculating the negative forcing associated with aerosols, are the Lapse Rate and Water Vapor feedbacks included in the total forcing effect?

Depends on the source you are looking at. If its old it won't have, if its recent it might have but you'll need to check the paper to be sure.
Title: Re: Stupid Questions :o
Post by: jai mitchell on February 25, 2016, 07:11:30 PM
was able to find the answer, forcing does not include feedbacks it has different units.  ECS includes feedbacks to determine a time-rated forcing value in future projections. 

forcing is a measure of energy per square meter and is instantaneous at any given time.
Title: Re: Stupid Questions :o
Post by: johnm33 on April 01, 2016, 10:12:15 PM
I've been trying to find something definitive about tides in Kangia/jakobshavn fjord, anyhow I decided to have a shot at ball park figures. What I want is some estimate of max and minimum turnover of water possible per tide. So tidal min. with onshore winds when there's a logjam of icebergs stopping any movement at the cill, verses tidal max with full bore offshore winds and bergs racing down the fjord. In Km3 I get from .1 to maybe 10! [7.8]  Why am I wrong?
Title: Re: Stupid Questions :o
Post by: johnm33 on April 04, 2016, 10:51:11 PM
These are my assumptions
. First for the minimum, the fjord is full of icebergs both it and the side channels are frozen over and covered in snow. There's a logjam of icebergs sitting on the cill there's no surface movement, and there's a low tide in Disko
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fpuu.sh%2Fo4o6z%2F35cd3ba508.png&hash=405ab6b50786769dce98ec3a6b995e18)
say .4m .
So 55x6x.0004[km]=0.132Km3 the tide simply doesn't have the power to push past the 'dam' into the fjord.
Now the max. The whole fjord and the side channels are fluid the run of increasing tides have destroyed the logjam, there are powerful winds blowing offshore adding to the inertia of the icebergs as they flow out in the surface freshwater current. Out in Baffin strong winds have been blowing the 1m thick ice south for days, and the tidal range is at it's peak.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fpuu.sh%2Fo4oyd%2F940ce1564c.jpg&hash=81c0005547da27080f698ae0f67154a7)
The surface outflow of the ebbing tide say 55x6x.0024[km]=.792 , plus the side channels say x2.2 so 1.74 and to that add in some inertia for the ongoing fresh water surface current continuing to run throughout the incoming tide, [which comes in at the base] say 70% so maybe 2.96Km3 the last forcing factor is when conditions are right [and it looks like they are at present] there's an increased flow of warm irminger water thats drawn up from the south from the wgsc[slope current] and when it's forced to run it preferentially flows up the deep channels connected to deeper Baffin waters, only those fjords with such a connection [IIf does] experience this forcing and since it's difficult to find any information on it [the flow] some serious speculation. Would an undersea river forcing it's way east double the force of the tidal flow? My own view is that it might peak at something like 3 times the flow and once established it's inertia would carry it through into the ebb whilst the necessary conditions for it's forcing prevail. So best guess at peak tidal flux 7.8Km3 and since it's speculation +/- 25% margin of error.
Why am I wrong?
Title: Re: Stupid Questions :o
Post by: Sigmetnow on April 11, 2016, 06:48:52 PM
This may be a doozy of a Stupid Question, but it puzzles me:

Why not substitute Propane for natural gas?  (As an interim measure, while we ramp up renewables.)

I believe propane generates slightly less power than natural gas, but surely the reduction in greenhouse gas effect would make that worthwhile. 
Title: Re: Stupid Questions :o
Post by: RoxTheGeologist on April 11, 2016, 08:18:03 PM
1)Propane has lower energy per g CO2 emitted, and has to be refined which adds to its gCO2 per Mj.
Methane has the disadvantage that it is a powerful short lived GHG, so any upstream leaks of methane add to the gCO2/Mj.

2)I'm not sure it would be a easy solution: switching over all burners to propane as they would have to be re-certified for NOx emissions. The infrastructure requirements and cost for switching between the two would, probably, hugely out weigh any potential emissions reductions (if there are any).

3)Propane is not as readily available, and passing any legislation that requires the switch would be extraordinarily difficult and take years to implement. As someone involved in advocating low carbon fuel usage, my experience has been that changing the status quo pits you against very able and well funded lobbyist from the entrenched industries.
Title: Re: Stupid Questions :o
Post by: seaicesailor on April 18, 2016, 10:30:44 PM
Living in a place where snow appears once every two years or so...
Anybody knows what effect continuous insolation may have on snow for high-pressure cold (well below freezing) dry clear-sky days? Possible sublimation? Some really significant change of texture or not?
Just wondering what happens to snow under current High (apart from being blown around)
Thx!
Title: Re: Stupid Questions :o
Post by: Andreas T on April 18, 2016, 11:40:29 PM
have a look at the stuff in front of the camera lens on Obuoy14. It doesn't look like melting, maximum temperatures have been below  -15 degC but it is getting less.
compare current image with
.....

It hasn't finished deicing itself yet, but does nonetheless reveal some sunbeams and a clear blue sky today:
Title: Re: Stupid Questions :o
Post by: seaicesailor on April 18, 2016, 11:44:36 PM
have a look at the stuff in front of the camera lens on Obuoy14. It doesn't look like melting, maximum temperatures have been below  -15 degC but it is getting less.
compare current image with
.....

It hasn't finished deicing itself yet, but does nonetheless reveal some sunbeams and a clear blue sky today:
Thanks Andreas. But I ask myself if in that case the sun heating the camera and the metal holding it doesn't have to do with it
Title: Re: Stupid Questions :o
Post by: Andreas T on April 18, 2016, 11:55:54 PM
it is the very slow disappearance of the frost or blown snow in front of the camera which could be sublimation I think, but I don't claim any expertise on this. What has caught my eye is that relative humidity at Obuoy14 is going up and down with temperature whereas it goes down when temperature goes up at Obuoy13 (the more usual way) could that have something to do with more of this stuff near the humidity sensor?
Title: Re: Stupid Questions :o
Post by: seaicesailor on April 19, 2016, 09:43:24 AM
it is the very slow disappearance of the frost or blown snow in front of the camera which could be sublimation I think, but I don't claim any expertise on this. What has caught my eye is that relative humidity at Obuoy14 is going up and down with temperature whereas it goes down when temperature goes up at Obuoy13 (the more usual way) could that have something to do with more of this stuff near the humidity sensor?

This small paper estimates that of the total snowfall in the Arctic Ocean, a 40% is removed by sublimation,(!) a 10% by wind blowing sublimation, a 40% by melting and 10% other causes. Being a model the exact numbers are not so relevant as the fact that sublimation is on the same order as melting. That may explain the humidity correlation in #14 too.

So I may speculate with some confidence that much snow is being gone right now given the strong High, the sustained sun radiation, and winds currently in most of the Pacific side of the Arctic.

http://goo.gl/u193G9 (http://goo.gl/u193G9)
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on April 27, 2016, 01:58:49 PM
Hi Guys!

Looking for a bit of info on the amount of energy required to melt ice compared to what it takes to 'warm' the same volume of water.

It's important for me as I want to get some notion of the amount of energy/heating that might be at the disposal of the basin should we see areas melt vout earlier than they have in past years.

If low ice in Barentsz/Kara can lie behind the energy needed to warp the Weather over the N.Hemisphere then I'd be keen to understand just how much more of a shove a big, early, melt would impart to the system?
Title: Re: Stupid Questions :o
Post by: pikaia on April 27, 2016, 02:08:36 PM
To melt 1Kg of ice requires 80 Calories. To raise the temperature of 1Kg of water by 1 degree requires 1 Calorie.
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on April 27, 2016, 02:53:18 PM
To melt 1Kg of ice requires 80 Calories. To raise the temperature of 1Kg of water by 1 degree requires 1 Calorie.

WOW!!!!

Just wow! Thanks for that Pikaia!
Title: Re: Stupid Questions :o
Post by: Buddy on April 27, 2016, 03:13:29 PM
Quote
To melt 1Kg of ice requires 80 Calories. To raise the temperature of 1Kg of water by 1 degree requires 1 Calorie.

So the less ice there is....the faster the oceans will warm up.   The oceans will warm faster now that all that energy previously used to melt more ice.....can now be leveraged to warm oceans instead and its much easier to warm oceans than it is to melt ice.  I had noted on another topic stream....that my concern is that climate scientists had underestimated (or "undercalculated":) the melting of the Arctic ice sheet.

And...if they have underestimated the melting of the Arctic ice sheet....that would lead to more rapid warming than modeled because (a) oceans would warm more quickly (b) feedbacks like permafrost melting would take place sooner......and all those physical actions "downstream" from the melting of ice sheets would lead to a logarithmic escalation of atmospheric temperatures (until we get further along the process moving towards an equilibrium).

Maybe those of you with a physics background can tell me where I have missed the boat (or perhaps even missed the dock as well ::)




Title: Re: Stupid Questions :o
Post by: DoomInTheUK on April 27, 2016, 03:30:07 PM
That's 1g of water by 1 deg C = 1 calorie, not 1Kg.
Title: Re: Stupid Questions :o
Post by: pikaia on April 27, 2016, 03:42:03 PM
It depends which Calorie you are talking about.Calorie with an upper case "C" is the bigger one.

https://en.wikipedia.org/wiki/Calorie
Title: Re: Stupid Questions :o
Post by: TerryM on April 27, 2016, 04:01:04 PM
I believe the ratio of 1 to 80 remains regardless of what units are used for mass or energy.

I also believe the salt in sea water alters this ratio, although not by a significant amount.

One of my pet projects is wondering where the energy no longer being used to melt that last million kg of ice goes, and how that energy gets dissipated.

Terry
Title: Re: Stupid Questions :o
Post by: johnm33 on April 27, 2016, 05:16:25 PM


One of my pet projects is wondering where the energy no longer being used to melt that last million kg of ice goes, and how that energy gets dissipated.

Terry
My guess evaporation, but does it fall, or settle? and where?
Title: Re: Stupid Questions :o
Post by: DoomInTheUK on April 27, 2016, 05:30:40 PM
In the short term the heat will mostly get captured in the first few hundred meters of sea. Some will drive extra evaporation, but most will just go into warming the water.

Ocean currents will then drag that heated water either along, or down. The Arctic will behave no differently than any other partly enclosed sea.

There's an awful lot of water up there to absorb that heat.
Title: Re: Stupid Questions :o
Post by: abbottisgone on April 28, 2016, 09:53:01 AM
This may be a doozy of a Stupid Question, but it puzzles me:

Why not substitute Propane for natural gas?  (As an interim measure, while we ramp up renewables.)

I believe propane generates slightly less power than natural gas, but surely the reduction in greenhouse gas effect would make that worthwhile.
LPG (propane) is more dense than air, at a relative density of 1.5219:1 vs natural gas (methane) at 0.5537:1, which is lighter than air.

source: http://www.elgas.com.au/blog/486-comparison-lpg-natural-gas-propane-butane-methane-lng-cng (http://www.elgas.com.au/blog/486-comparison-lpg-natural-gas-propane-butane-methane-lng-cng)
Title: Re: Stupid Questions :o
Post by: Burnrate on May 16, 2016, 07:29:49 PM
Can someone give me an overview, explanation, point me to some links that explains the current satellite and data situation?

I've read something about the integration of F18 satellite data.  This (http://www.wmo-sat.info/oscar/satellites/view/65 (http://www.wmo-sat.info/oscar/satellites/view/65)) shows that there are no operationsl DMSP satellites.  This (http://arctic.atmos.uiuc.edu/cryosphere/ (http://arctic.atmos.uiuc.edu/cryosphere/)) says that there has been bad data since the beginning of April but no further word on what is being worked on.

Do we expect a return of the Cryosphere today data?  Will they fill in the gaps when things get calibrated?  Any ETA on a fix or replacement?  Where do I go to get updates on the the situation and what the plans are looking forward?  Where should I look to replace the information I was getting from those sources?
Title: Re: Stupid Questions :o
Post by: oren on May 16, 2016, 07:31:10 PM
I can only say that in the meantime be sure to check the IJIS thread for daily updates on extent.
Title: Re: Stupid Questions :o
Post by: crandles on May 16, 2016, 07:39:51 PM
I would suggest check out Wipneus' data if you need area in CT style:
from 2016 sea ice area and extent data thread:

If CT would have, I could have reported a -180k drop is expected for coming Friday.:

day  CT-date       NH               SH                Global
Mon 2016.3479  -75.3 10.917531  +95.8  7.285143   +20.5 18.202674
Tue 2016.3507  -11.6 10.905968  +45.0  7.330120   +33.4 18.236088
Wed 2016.3534  -35.6 10.870406  +79.9  7.410037   +44.4 18.280443
Thu 2016.3562  -39.3 10.831096 +143.9  7.553953  +104.6 18.385049
Fri 2016.3589 -181.9 10.649181  +42.4  7.596343  -139.5 18.245524


I put something together here. Will that do for you?

https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data/AreaCalculatedLikeCryosphereToday.txt (https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data/AreaCalculatedLikeCryosphereToday.txt)

Re: Some links that explain

Above file contain link to
https://nsidc.org/data/nsidc-0081 (https://nsidc.org/data/nsidc-0081)
there is also
http://nsidc.org/arcticseaicenews/2016/05/ (http://nsidc.org/arcticseaicenews/2016/05/)
Title: Re: Stupid Questions :o
Post by: Dundee on May 28, 2016, 06:35:03 PM
Today Wipneus (09:06:36 AM) noted that NSIDC updated "final" data through 12/31/2015 - I assume gridded concentration data?.

I am putting this in "Stupid Questions" because, to be honest, the more I know about the data environment the more I can see I don't know, and I don't want to clutter the 2016 data thread.

First - background. I have been toying with the statistical behavior of NH daily ice extent. I have been using the NSIDC data set from sidads.colorado.edu (final spliced to nrt). I am at the point where I want to do an analysis run I can talk about in public. Because the statistical chain is tedious (and laborious, at least with the tools I have available) I'd like to start with the most current and complete data I can.

Again, I am looking at NSIDC ice extent for the Arctic overall. The latest final numbers I currently have run through 12/31/2014 (NH_seaice_extent_final.csv dated 04/21/2016 07:44AM). Is there a set somewhere running through 2015?

Next, The path I am on can lead to a projected minimum, but not with March 31st data. Is the data Wipneus computes from DSMP F18 (nsidc_nt_nrt_main.txt - I think) a like product to the sidads.colorado.edu? I recognize it is uncalibrated (the effect of which I'll need to consider) but what I am asking is am I on the right track or am I trying to combine two unlike products? What I anticipate ending up is working up a forecast model exclusively from the "official" data, then looking at how things come out for this year, after extending the official view with Wipneus calculations or using his numbers exclusively for the current season, depending on how the statistics work out.

Finally, are the numbers from both Wipneus and sidads.colorado.edu actual daily numbers, or has the five day average (used in NSIDC's public graphs) already been applied to one or both?

I would rather know what I am looking at (or only thought I was looking at) now rather than at the end of a long analysis chain . . .

Thanks!
Title: Re: Stupid Questions :o
Post by: ktonine on May 28, 2016, 06:56:57 PM
Dundee - all of the data that we use is publicly available. 

Off of the main blog page, under Arctic Sea Ice Graphs (https://sites.google.com/site/arcticseaicegraphs/), you'll find links to:
NSIDC sea ice extent daily data
NSIDC sea ice area and extent monthly data
NSIDC/NIC MASIE homepage and daily data
JAXA (ADS-NIPR) sea ice extent daily data
Cryosphere Today Arctic sea ice area daily data
Cryosphere Today Antarctic sea ice area daily data
Cryosphere Today Global sea ice area daily data
PIOMAS ice volume 1979-present daily data
Arctic ROOS area and extent monthly data

Here on the Forum if you go back up to the Home page, select the 'Developer's Corner (http://forum.arctic-sea-ice.net/index.php/board,24.0.html)' under AGW in General.  Wherein you'll also find links to many of the data sourcees.
Title: Re: Stupid Questions :o
Post by: Wipneus on May 28, 2016, 07:13:30 PM
Today Wipneus (09:06:36 AM) noted that NSIDC updated "final" data through 12/31/2015 - I assume gridded concentration data?.
Yes. There is also NSIDC extent, or "Ice Index" calculated from the final data, here:
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/NH_seaice_extent_final.csv

But this has not been updated for a while. Surprising because it is still based on version 1 of the SIC data. The SIC data is now replaced by version 1.1, with substantial modifications in the years 1979-1999.

All MY calculations now use version 1.1.
Quote
I am putting this in "Stupid Questions" because, to be honest, the more I know about the data environment the more I can see I don't know, and I don't want to clutter the 2016 data thread.

First - background. I have been toying with the statistical behavior of NH daily ice extent. I have been using the NSIDC data set from sidads.colorado.edu (final spliced to nrt). I am at the point where I want to do an analysis run I can talk about in public. Because the statistical chain is tedious (and laborious, at least with the tools I have available) I'd like to start with the most current and complete data I can.

Again, I am looking at NSIDC ice extent for the Arctic overall. The latest final numbers I currently have run through 12/31/2014 (NH_seaice_extent_final.csv dated 04/21/2016 07:44AM). Is there a set somewhere running through 2015?
Yes, use mine, it is using version 1.1 as well!
Quote

Next, The path I am on can lead to a projected minimum, but not with March 31st data. Is the data Wipneus computes from DSMP F18 (nsidc_nt_nrt_main.txt - I think) a like product to the sidads.colorado.edu? I recognize it is uncalibrated (the effect of which I'll need to consider) but what I am asking is am I on the right track or am I trying to combine two unlike products? What I anticipate ending up is working up a forecast model exclusively from the "official" data, then looking at how things come out for this year, after extending the official view with Wipneus calculations or using his numbers exclusively for the current season, depending on how the statistics work out.
When we are using the same input (sea ice concentration) data, my shadow extent number are the same as those from NSIDC, exactly if you take into account that NSIDC rounds figures to 1000's of km2.
(CT-area numbers are less exact, but almost always are with 1k)
Quote

Finally, are the numbers from both Wipneus and sidads.colorado.edu actual daily numbers, or has the five day average (used in NSIDC's public graphs) already been applied to one or both?

I would rather know what I am looking at (or only thought I was looking at) now rather than at the end of a long analysis chain . . .

Thanks!

I do not average, neither is NSIDC in their *daily* numbers.

My final NSIDC extent and area data:
https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data/nsidc_nt_final_main.txt.gz?attredirects=0&d=1

same per regio:
https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data/nsidc_nt_final_detail.txt.gz?attredirects=0&d=1

Near Real Time (including post 31 March, uncalibrated F18 data) extent and area:
https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data/nsidc_nt_nrt_main.txt?attredirects=0&d=1
same per regio:
https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data/nsidc_nt_nrt_detail.txt?attredirects=0&d=1


Title: Re: Stupid Questions :o
Post by: Dundee on May 28, 2016, 07:51:12 PM
Again, thanks!

I've seen all the data sources on ASIG (barring dead links) and many, many others besides - so many it was becoming unclear what the distinctions were.

I knew there was a change in the SIC and probably should have been able to work out (but didn't) from the source data field in NH_seaice_extent_final.csv that this older "final" data was based on 1.0.

Thanks for clarifying which of your files to look at, and the moving average question. I was pretty sure what I was looking at had not been averaged, but if it had been I'd be treating it inappropriately.

I am looking at a distinct change in statistical behavior that occurs in the months around peak melt. If an effective forecast is to come of it, I'd have to be able to state that, in a particular year, that shift had or had not occurred on a given date (the closer to real time, the better). If it turns out I only know reliably the transition has occurred well after the fact it would be interesting, but have no forecast value. Of course if I was trying to draw conclusions from two datasets that were not as related to each other as I imagined, that would have no forecast value either (no matter what the spreadsheet says). Hence the stupid questions, before I start invest real time in the analysis.
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on May 31, 2016, 06:05:46 PM
Hi Guys!

 Can you help me to flesh out the energy we see from an 'average Nino' compared to the energy an ice free basin , mid July to mid Sept, would provide?

I was thinking that a Nino is probably a 1 in 7 year event so I would need to add up 7 years worth of 'ice free' energy to see how it compares to a nino's output.

Anybody got any input?
Title: Re: Stupid Questions :o
Post by: Ice Shieldz on May 31, 2016, 07:37:14 PM
Hi Guys!

 Can you help me to flesh out the energy we see from an 'average Nino' compared to the energy an ice free basin , mid July to mid Sept, would provide?

I was thinking that a Nino is probably a 1 in 7 year event so I would need to add up 7 years worth of 'ice free' energy to see how it compares to a nino's output.

Anybody got any input?
Hi Gray-Wolf, so you're asking what the amount of solar insolation input into the arctic ocean would be?  Of course nino is mostly a transfer of heat from the ocean to the atmosphere. 

For both arctic input and nino transfer, I too would be interested in knowing what the cumulative watts are over given time frames.  Perhaps a good place to start would be in existing research papers with necessary data and/or equations. 

I remember reading from a questionable source that the amount of heat our 2015-16 nino transferred into the atmosphere is on par with the amount released by the Chicxulub asteroid that finished off the dinosaurs.  PS here is a bookmark-worthy Wikipedia page to put the magnitudes of energy we're talking about in perspective - https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy) (https://en.wikipedia.org/wiki/Orders_of_magnitude_(energy))
Title: Re: Stupid Questions :o
Post by: Andreas T on May 31, 2016, 09:24:47 PM
I don't have a straightforward answer, so feel free to skip the following musing on the topic. I hope though I can provide some pointers to what a reasonable answer should include.
If you want just a simple and crude figure you might take the incoming solar radiation at that latitude (integrated over the arctic ocean ideally), at the top of the atmosphere the number is easy to work out, and multiply with a change in albedo ice free / present average ice cover.
That number would be too high because less of that radiation reaches the surface even on a clear day  and because much less (although still some) reaches it on cloudy days. Then it is very difficult to say whether an ice free arctic ocean would be more or less cloudy.
The other thing which would have to be figured out somehow is whether an ice free arctic in the summer means more heat lost into space in the winter. It is generally accepted I think that in order to have ice free summers every year the ice must be thinner than it is now at the beginning of summer. This would mean a warmer ice surface in the winter which if everything is the same looses more heat by radiating at a higher intensity out to space in a clear arctic night.
This can be reduced by cloudier skies than now but even then those clouds will radiate out to space and can only be maintained by continuing updraft of warmer and moister air.

Some idea of the incoming solar radiation at ground level the arctic ocean receives now (up to end of 2015) can be found here  https://ceres-tool.larc.nasa.gov/ord-tool/srbavg (https://ceres-tool.larc.nasa.gov/ord-tool/srbavg)
it lets you choose an area for which it displays monthly average radiative fluxes calculated on the basis of observations of cloudiness etc.
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on June 01, 2016, 02:43:29 PM
I don't have a straightforward answer, so feel free to skip the following musing on the topic. I hope though I can provide some pointers to what a reasonable answer should include.
If you want just a simple and crude figure you might take the incoming solar radiation at that latitude (integrated over the arctic ocean ideally), at the top of the atmosphere the number is easy to work out, and multiply with a change in albedo ice free / present average ice cover.
That number would be too high because less of that radiation reaches the surface even on a clear day  and because much less (although still some) reaches it on cloudy days. Then it is very difficult to say whether an ice free arctic ocean would be more or less cloudy.
The other thing which would have to be figured out somehow is whether an ice free arctic in the summer means more heat lost into space in the winter. It is generally accepted I think that in order to have ice free summers every year the ice must be thinner than it is now at the beginning of summer. This would mean a warmer ice surface in the winter which if everything is the same looses more heat by radiating at a higher intensity out to space in a clear arctic night.
This can be reduced by cloudier skies than now but even then those clouds will radiate out to space and can only be maintained by continuing updraft of warmer and moister air.

Some idea of the incoming solar radiation at ground level the arctic ocean receives now (up to end of 2015) can be found here  https://ceres-tool.larc.nasa.gov/ord-tool/srbavg (https://ceres-tool.larc.nasa.gov/ord-tool/srbavg)
it lets you choose an area for which it displays monthly average radiative fluxes calculated on the basis of observations of cloudiness etc.

Hi! It is the heat that is there to escape ( like the Nino?) that I wish to get a ballpark figure for. I think it would be very useful for me to have such info as , currently, I'm fed up with deniers telling me the recent hike in global temps " was all El Nino"..... and not the tiny bit on top that climate scientists tell us Nino added?

If I could counter with just how much energy the autumn ocean is pouring into the atmosphere each year, and a figure in Nino terms, of how much an open Arctic ocean would bring to the planet, then they might not be able to argue it away?

As for 'lost to space'? The northern lanmasses will be able to cool far faster than the ocean , come Autumn, so won't this leave an imbalance that Nature would like to fill?
Title: Re: Stupid Questions :o
Post by: DavidR on June 02, 2016, 12:52:53 AM
Currently, I'm fed up with deniers telling me the recent hike in global temps " was all El Nino"..... and not the tiny bit on top that climate scientists tell us Nino added?
Perhaps the attached graph will help. It  shows temperature anomalies for the 1997/98 and 2015/16 El Ninos. The 2015/16 El Nino was not as strong  as 1997/98.

The difference in the anomaly, shown by the black line, represents the global warming, since 1998, component of the recent temperatures.

If in fact it was all down to El Nino the black line should be below 0 because 1997/98 was stronger than 2015/6.
Title: Re: Stupid Questions :o
Post by: Andreas T on June 02, 2016, 01:06:12 AM
The key point is that El Nino doesn't generate heat or increases energy uptake by the Earth, it releases energy stored in the pacific ocean. That redistribution is larger than what global warming adds in a single year, sure, but this El Nino can produce higher temperatures than previous ones because the Earth as a whole has been accumulating more energy each year through global warming.
Title: Re: Stupid Questions :o
Post by: JimboOmega on June 03, 2016, 04:19:38 AM
Does GFS include the ice extent in its modeling?

Specifically, if there are anomalous ice conditions, does that mess up its temperature forecasts?  (I'm looking at cci-reanalyzer, specifically)
Title: Re: Stupid Questions :o
Post by: Michael Hauber on June 03, 2016, 05:37:51 AM
Does GFS include the ice extent in its modeling?

Specifically, if there are anomalous ice conditions, does that mess up its temperature forecasts?  (I'm looking at cci-reanalyzer, specifically)

yes (http://www.nws.noaa.gov/ost/climate/STIP/seaice.htm)

But current conditions are detected by SSM/I which is malfunctioning.  Whether that is enough to mess up its temperature forecasts I don't know.
Title: Re: Stupid Questions :o
Post by: seaicesailor on June 03, 2016, 02:52:50 PM

Today there's a good example for a question I've got. I have understood, from reading comments here, that Modis false-color images 3-6-7 could indicate surface melting wherever the surface looks more reddish than orange. Lately I started to follow cues that the images 7-2-1 could be better indication of surface melting wherever blue becomes dark blue.

Below a Modis tile of today showing part of ESS and CAB.
The 3-6-7 image (left) is very much red for the whole area without clouds, when compared to Beaufort sea (not in the image). However the 7-2-1 image shows blue gradually getting darker only in a smaller extension closer to the coast.

Anybody would know what is a better indicator of surface melting? BTW, it goes without saying I have not  idea what 3-6-7 or 7-2-1 channel combinations mean.
Title: Re: Stupid Questions :o
Post by: Andreas T on June 03, 2016, 10:42:40 PM
there is some information on the 3-6-7 and 7-2-1 images here
 https://earthdata.nasa.gov/faq#ed-rapid-response-faq (https://earthdata.nasa.gov/faq#ed-rapid-response-faq)
As I understand it the more orange shade of red indicates finer crystals of ice, i.e. high clouds or fine snow. Snow which has warmed to its melting point and has coarser grains of ice becomes similar to ice in appearance (red). Therefore 3-6-7 will show the onset of surface melt before 7-2-1 which shows water on the surface more strongly (see the landfast ice east of the Lena delta today versus yesterday)
http://go.nasa.gov/24naZlm (http://go.nasa.gov/24naZlm)
Title: Re: Stupid Questions :o
Post by: seaicesailor on June 04, 2016, 02:27:52 AM
Thank you Andreas!
Title: Re: Stupid Questions :o
Post by: JimboOmega on June 06, 2016, 11:29:38 PM
Where do people get MODIS images?
Title: Re: Stupid Questions :o
Post by: Laurent on June 06, 2016, 11:38:15 PM
4 km range
https://lance.modaps.eosdis.nasa.gov/imagery/subsets/?mosaic=Arctic

Click on a tile to get some more precise choices.
Change the date in the address bar.

You have also this link that is for the whole world :
https://lance.modaps.eosdis.nasa.gov/cgi-bin/imagery/realtime.cgi
Title: Re: Stupid Questions :o
Post by: Jim Hunt on June 06, 2016, 11:43:00 PM
Where do people get MODIS images?

Worldview is the easiest venue (IMHO). Try Andreas' most recent link, and maybe this one too?

http://go.nasa.gov/1ZsGDNa (http://go.nasa.gov/1ZsGDNa)

Then do a screengrab or click the camera icon at the top right.
Title: Re: Stupid Questions :o
Post by: Okono on June 07, 2016, 12:45:03 AM
BTW, it goes without saying I have not  idea what 3-6-7 or 7-2-1 channel combinations mean.

This is cobbling together knowledge from several places, so if it's wrong, someone please correct me.

AFAIK, they're frequencies of light, "channel" or "band" generally being shorthand for "wavelength".  The numbers are a conventional mapping from satellite frequency to numbers that can be remembered easily.

This then gets mapped to displayed colors, R-G-B.  Wavelength and brightness on the screen are based on the wavelength conventions and the order.

Here are some example combinations and example interpretations of colors based on the combinations.

http://maps.unomaha.edu/Peterson/gis/notes/RS2.htm (http://maps.unomaha.edu/Peterson/gis/notes/RS2.htm)

Next life, I'm planning on my eyeballs going C-M-Y-K, but it's already possible to do fancier combinations than these quick ones.
Title: Re: Stupid Questions :o
Post by: seaicesailor on June 07, 2016, 12:49:54 AM
Thanks Okono : -)
Title: Re: Stupid Questions :o
Post by: Okono on June 07, 2016, 01:03:29 AM
No problem, I just hope it's all correct.  I think it is.  I found the same explanation on the page I linked.

I can ask a follow-up that is immediately relevant to your question in the melting thread, though, and I can't answer it as well, so:

Can anyone give example band mappings and how to interpret the colors for satellites that cover the Arctic?

edit: "sorry, beyond the information on 3-6-7 and 7-2-1 with MODIS linked to in the FAQ earlier at:"

https://earthdata.nasa.gov/faq#ed-rapid-response-faq
Title: Re: Stupid Questions :o
Post by: Jim Hunt on June 07, 2016, 01:46:15 PM
MODIS bands are documented at

http://modis.gsfc.nasa.gov/about/specifications.php (http://modis.gsfc.nasa.gov/about/specifications.php)
Title: Re: Stupid Questions :o
Post by: Andreas T on June 07, 2016, 02:03:14 PM
Not something which is much help at the moment, but I have started a thread http://forum.arctic-sea-ice.net/index.php/topic,1573.0.html (http://forum.arctic-sea-ice.net/index.php/topic,1573.0.html)
 (a bit out of the way, but that means it does not fill quickly with other issues)
I want to collect examples of images where the colours can be related to known features, so we build up a kind of library of situations where parallels can be drawn from known situations to unknown ones. That's how experienced analysts of these thing work I guess, gaining experience from previous correlations.

The first example I posted shows darkened ice on a floe which I know is thinner ice by tracking this floe since over a couple of months. In the same shot landfast ice shows similar darkening but the 7-2-1 image shows one to have a watercovered surface and the other not.
Title: Re: Stupid Questions :o
Post by: JimboOmega on June 07, 2016, 09:18:38 PM
What site has a good "nowcast" (temps, winds, clouds) of the arctic? Is there one with good recent (i.e. last few days) data?
Title: Re: Stupid Questions :o
Post by: mmghosh on June 09, 2016, 04:59:24 PM
When Climate Reanalyzer reports on temperatures at 2 meters, do they mean 2 meters above ground level or 2 meters in snow/water/buoys?

Title: Re: Stupid Questions :o
Post by: jdallen on June 09, 2016, 05:13:20 PM
When Climate Reanalyzer reports on temperatures at 2 meters, do they mean 2 meters above ground level or 2 meters in snow/water/buoys?
2 meters above ground. That helps avoid microclimate conditions.
Title: Re: Stupid Questions :o
Post by: gregcharles on June 15, 2016, 06:29:21 PM
Wipneus reports on CT Area (example (http://forum.arctic-sea-ice.net/index.php/topic,1457.msg80296.html#msg80296)) using CT Dates. The day of the week generally shows that the latest date is either five days in the past or two in the future. For example, today is Wednesday, and the latest value in that data is labeled Fri 2016.4548. How can the dates be translated to human-readable form?
Title: Re: Stupid Questions :o
Post by: Hugabufallo on June 16, 2016, 11:52:25 PM
Hi, I'm a complete novice when it comes to the dynamics and intricacies of the arctic ocean melt cycle. However I have been reading what a lot of you have had to say on the matter for the past few months or so with great interest.

Due to my lack of knowledge on the scientific side of things I have been focusing on satellite imagery of various parts of the arctic and how the ice changes and moves around over time and how that differs to previous years. I was wondering if there are any suitable resources for tracking the movement of the entire arctic ice pack over time other than satellites?

The reason being that in the last week the entire outer edge of the ice seems to be rotating anticlockwise round the whole of the arctic. I was wondering whether due to the rapid change that is occurring in the temperatures of our oceans and the changing structure and increasing fragility of the ice pack that we might (in the future) see a large change in how the entire arctic ice moves about and whether this could have a significant impact on the freeze/melt cycle?

Sorry in case there is any incoherence in this post, English is my first language.
Title: Re: Stupid Questions :o
Post by: Neven on June 17, 2016, 12:00:49 AM
Welcome, Hugabuffalo.

Ice drift/movement is largely driven by winds, which are driven by (differences in) atmospheric pressure. It could be that AGW is changing these patterns, but it takes a long time to gather enough statistical evidence. One thing is for sure and that is that as ice gets thinner, it becomes more mobile/easier to move.
Title: Re: Stupid Questions :o
Post by: Hugabufallo on June 17, 2016, 12:21:51 AM
Thanks.

It is a shame that we are changing the globe so rapidly. Perhaps by the time we have gathered such evidence all the ice will be gone and it will be but a curiosity. I feel like we are just on a rollercoaster looking backwards sometimes.
Title: Re: Stupid Questions :o
Post by: anotheramethyst on June 17, 2016, 07:07:17 AM
Wipneus reports on CT Area (example (http://forum.arctic-sea-ice.net/index.php/topic,1457.msg80296.html#msg80296)) using CT Dates. The day of the week generally shows that the latest date is either five days in the past or two in the future. For example, today is Wednesday, and the latest value in that data is labeled Fri 2016.4548. How can the dates be translated to human-readable form?

It's because wipneus is a prophet :) haha just kidding.  It takes CT area a few days to process and release their data, but they release the raw data immediately.  Wipneus figured out their formula and calculates it for us the same day, with a small margin of error.  When CT releases the data, wipneus adjusts his numbers, if necessary. So wipneus is telling us the numbers sattelites received that day, but he writes thedate that the num ers will officially be released.  Kt'sone of a thousand incredible tbings wipneus does around here, including supplying us with data when other agencies weren't releasing any official numbers.  I think if any of us ever run into wipneus in person, we should immediately hand over some beer. 
Title: Re: Stupid Questions :o
Post by: binntho on June 17, 2016, 09:09:10 AM
It's because wipneus is a prophet :) haha just kidding.  It takes CT area a few days to process and release their data, but they release the raw data immediately.  Wipneus figured out their formula and calculates it for us the same day, with a small margin of error.  When CT releases the data, wipneus adjusts his numbers, if necessary.

I'm still not clear on how to read the dates in Wipneus' posts, for instance this one from yesterday (Thursday):


day  CT-date       NH               SH                Global
Wed 2016.4493   +7.8  8.576390 +104.3 10.728776  +112.1 19.305166
Thu 2016.4521  -57.1  8.519276  +52.5 10.781309    -4.6 19.300585
Fri 2016.4548 -108.3  8.410998  +66.3 10.847582   -42.0 19.258580
Sat 2016.4575  -40.5  8.370483  +95.5 10.943110   +55.0 19.313593


Which of the four days is "today": Thursday the 16th of June?

... if any of us ever run into wipneus in person, we should immediately hand over some beer.

Totally agree!
Title: Re: Stupid Questions :o
Post by: Wipneus on June 17, 2016, 09:43:19 AM

I'm still not clear on how to read the dates in Wipneus' posts, for instance this one from yesterday (Thursday):


day  CT-date       NH               SH                Global
Wed 2016.4493   +7.8  8.576390 +104.3 10.728776  +112.1 19.305166
Thu 2016.4521  -57.1  8.519276  +52.5 10.781309    -4.6 19.300585
Fri 2016.4548 -108.3  8.410998  +66.3 10.847582   -42.0 19.258580
Sat 2016.4575  -40.5  8.370483  +95.5 10.943110   +55.0 19.313593


Which of the four days is "today": Thursday the 16th of June?


Binnto, I have tied myself to the rather clumsy way that CT reports time and when. Because CT's method does not seem to  be unambiguous and different people interpret if in several ways I am giving you two dates.
The first date is the date that CT is expected to report the value. Everybody should agree about that as long as CT reports ( which it does not at the moment).
The second is the date that will be in the CT data file, people that interpret CT's data file can find it back there.

If this is all too confusing (I can imagine), remember the last line is always based on the latest available data. That is the NSIDC data of the previous day, in this case 2016-06-15.
 
Title: Re: Stupid Questions :o
Post by: binntho on June 17, 2016, 10:10:23 AM
Ok, thanks Wipneus! I think I've got it now!
Title: Re: Stupid Questions :o
Post by: AmbiValent on June 17, 2016, 11:46:27 AM
When sunlight warms Arctic waters, does it only warm the (relative) freshwater surface layer or also deeper layers?
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on June 17, 2016, 12:44:33 PM
When sunlight warms Arctic waters, does it only warm the (relative) freshwater surface layer or also deeper layers?

I imagine where ever the sunlight penetrates too will feel the benefit as the incoming interferes with the water molecules? The top surface will 'milk' most of the energy though ( top 20m???)
Title: Re: Stupid Questions :o
Post by: Andreas T on June 18, 2016, 09:26:38 AM
The water warms by absorbing light (i.e. energy) so to answer your question you have to look at a "how much light goes in - how much light goes out " balance (like an accountants balance sheet).
A "layer" of water which lets light through to the lower water levels doesn't absorb it and doesn't warm (but it never is actually so clear that it absorbs none at all)
If a layer of thickness X absorbs 10% the next layer receives 90% of which it absorbs 10% (i.e.9% of the surface input) the next layer receives 81% .....
So absorption gets less and less because less and less comes into the deeper layers.
How large the thickness X is in my example depends on the "turbidity" of the water. Clear water absorbs over large depth , water rich in sediment or algae absorbs over a much smaller depth, assuming we talk about uniform clarity of the water over that depth, absorption is always higher near the surface where there is more light.
Absorbing over large depth means a large volume of water absorbs the incoming sunlight, so temperature will rise more slowly than if a thinner layer of smaller volume absorbs the same amount of energy. But it also looses less energy because its surface is less warm.

How that relates to the Arctic I don't actually know because I don't know how thick this fresher surface layer is and how clear it is. I suspect there will be large differences depending on location. Algae grow under and in the ice which can make melt water fairly murky I think.
Title: Re: Stupid Questions :o
Post by: JimboOmega on June 20, 2016, 10:59:19 PM
Does ice ever significantly "spread out"? I don't mean in terms of floes.

I mean, does thicker ice ever turn into thinner ice that covers a larger area in a significant way?  Or does it merely crack into floes where the overall covered area is the same?
Title: Re: Stupid Questions :o
Post by: magnamentis on June 20, 2016, 11:33:26 PM
no it won't spread like slime LOL, the latter is what happens. ice is a crystalline structure which can be crushed but not "flattened (rolled) like steel in a rolling mill or dough.

perhaps someone can confirm or deny since i'm not a glaciologist and under presser almost anything can change it's consistency what might happen at the bottom of glaciers, not sure though but a assumed you were talking about sea-surface ice, hence my 2 cents.
Title: Re: Stupid Questions :o
Post by: seaicesailor on June 21, 2016, 12:20:16 AM
I think that is right, although ice has some plasticity important for glaciers ( ice that has been submitted to high pressure) it is negligible for thin sea ice mechanics, I always assumed.

If you hear that sea ice can be treated as a viscous-plastic fluid, I think this is modelling for large-scale simulation purposes. Models (as HYCOM) cannot resolve meter or kilometer scale physics with fractures and ridges, so constitutive equations of 2D flow are developed with modeled terms akin to non linear viscosity (as thick chocolate, non newtonian fluid), ice mass conservation with sources terms (freezing), sink terms (melting), thickness divergence/compaction (as if gas expansion/contraction), external forces (wind pulling and ocean dragging, Coriolis) some inertia (not so important since the flow is typically viscosity-dominated as a very low speed flow)... and more.
But all that is for simulation of ice with coarse resolution.
I'd consider ice a fragile crystal. Not plastic. Crystal.
I may be wrong too
Title: Re: Stupid Questions :o
Post by: crandles on June 21, 2016, 12:25:22 AM
Take 2m thick sea ice. Crack off a bit averaging 1m wide. This is going to float on its side and have ~twice the area and ~half the thickness. There has surely got to be some of this but it is pretty small scale stuff and may well be negligible for most purposes.
Title: Re: Stupid Questions :o
Post by: seaicesailor on June 21, 2016, 12:29:02 AM
Take 2m thick sea ice. Crack off a bit averaging 1m wide. This is going to float on its side and have ~twice the area and ~half the thickness. There has surely got to be some of this but it is pretty small scale stuff and may well be negligible for most purposes.
Yes and since a big simulation cannot resolve that fracture it will calculate an stretched ice that is thinning out as a pizza mass
Title: Re: Stupid Questions :o
Post by: JimboOmega on June 21, 2016, 12:35:07 AM
Take 2m thick sea ice. Crack off a bit averaging 1m wide. This is going to float on its side and have ~twice the area and ~half the thickness. There has surely got to be some of this but it is pretty small scale stuff and may well be negligible for most purposes.
Yes and since a big simulation cannot resolve that fracture it will calculate an stretched ice that is thinning out as a pizza mass

It seems like so far, we've seen ice break into large chunks, but that's because we see from satellites which only have so much resolution.  And the ice being only single-digit meters thick, we would never see a situation where such a thing would happen.

But what about frazil ice? Is there a situation where formed "pack" ice degenerates to something more akin to a thin slush or soup (again, in any significant way, not just briefly at the margins or something).
Title: Re: Stupid Questions :o
Post by: seaicesailor on June 21, 2016, 12:42:28 AM
I have no idea, conservation laws, external sources and forces hold but internal forces  probably very difficult to model having lost integrity. Others may know better.
Title: Re: Stupid Questions :o
Post by: oren on June 22, 2016, 11:02:23 PM
Jimbo, I very much doubt it. Ice floes are large things, they might shatter at the edges and those pieces might float on their side (and melt and disappear very quickly) but will not normally turn into a huge heap of shattered ice cubes.
Title: Re: Stupid Questions :o
Post by: JR-ice on July 18, 2016, 01:21:28 AM
Okay, here's my "stupid question."

Why are the folks on the 2016 melting season thread tending to believe that this season is likely to not end up as a record?  At least it seems that a majority, especially of the longer-term posters, are saying that.

When I look at the NISDC daily graph, this season seems to be at the same point as 2012.  So, is it just a matter of whether a big storm comes along that weakens the ice?  If so, what is the probability of such a storm happening in the next three weeks? 

When I looked at Wipneus' graph showing the ratio of melt extent/total extent, it also doesn't seem that impossible - if melting extends later than normal - that this could be a record season?

Also, when I look at the "rubble" condition of the ice, to my totally untrained eye, it doesn't look that great.

So,  what are the things that other people looking at that leads them to believe that this would not be a record?  If we are coming off an El Nino, wouldn't there still be accumulated heat? 

Just wondering, and thanks for any help given.   

A concerned lurker, who hopes the ice lasts forever....
Title: Re: Stupid Questions :o
Post by: Tor Bejnar on July 18, 2016, 03:58:01 AM
JR-ice,
Near the end of June, I was guessing that, even though June was not good for melting (clouds, etc.) I predicted actual melt volume would 'keep up' with other years because of the warm late winter through May.  According to the PIOMAS model, however, June ice melt volume was even less than what Neven predicted.  Therefore, my guess 'proved' wrong - June weather is much more important than I thought. 

We have seen other years with a great deal of melange (rubble) in the CAB that never melted out.  It might be a little bit earlier this year, and a GAC (Great Arctic Cyclone), should another one occur, may have a larger window to 'disappear' a lot of ice.  But GACs are rare - only one summer-time GAC has been reported (I'm pretty sure).

Extreme weather could have a significant affect on Arctic ice these next two months, either positive or negative, but for that, time will tell.

My experience might give you some insight as to why so many don't expect a record year.
Title: Re: Stupid Questions :o
Post by: icy voyeur on July 18, 2016, 04:50:47 AM
Does ice ever significantly "spread out"? I don't mean in terms of floes.

I mean, does thicker ice ever turn into thinner ice that covers a larger area in a significant way?  Or does it merely crack into floes where the overall covered area is the same?

Do you mean, does 1,000,000 sq ft of 3 meter thick ice convert to 2,000,000 sq ft of 1.5 thick ice? Then no, not really.  Ice does not stretch out.  1,000,000 sq ft of 3 meter ice thins, first to something like 300,000 sq ft of 2 meter thick ice and 700,000 sq ft of 2.5 meter ice. Apologies for mixed dimensions and cartoonish simplifications.  But ice volume does not significantly flow into broader area.
Title: Re: Stupid Questions :o
Post by: Neven on July 18, 2016, 10:25:48 AM
My experience might give you some insight as to why so many don't expect a record year.

I'm with Tor on this one. And I'm looking at whether this year can end up in the top 3 (or top 4, as 2011 and 2015 were on a par). Breaking the record is nigh impossible.
Title: Re: Stupid Questions :o
Post by: AmbiValent on July 18, 2016, 10:30:36 AM
Looking at Wipneus' map, the current cyclone seems to have pushed ice towards the surrounding peripheral seas. Could that be accompanied by Ekman pumping of warmer deep water, or is there something missing for that to happen?
Title: Re: Stupid Questions :o
Post by: Nick_Naylor on July 18, 2016, 12:44:59 PM
Just imagine if we hadn't invented computers and launched satellites.

We might still be years from understanding what fossil fuel burning is doing to the climate, especially given the commitment certain folks still have to not understanding.
Title: Re: Stupid Questions :o
Post by: JR-ice on July 18, 2016, 06:50:02 PM
To Tor and Neven,

Thanks very much for taklng the time to read and respond to my message.  It was helpful.
 :)   :)

-Jessica
Title: Re: Stupid Questions :o
Post by: TerryM on July 18, 2016, 08:25:42 PM
Looking at Wipneus' map, the current cyclone seems to have pushed ice towards the surrounding peripheral seas. Could that be accompanied by Ekman pumping of warmer deep water, or is there something missing for that to happen?
Ekman pumping (the upwelling of deep, warm water due to cyclonic flows) breaks up the cold, fresh water layer protecting the ice from bottom melt. The low wandering about the Arctic for the past week is stirring things in this direction & will result in thinning if not the disintegration of affected ice.
Bottom melt and upwelling is difficult to see or measure, particularly with this year's dearth of buoys, but I do expect to note a drop in thin first year ice once the skies have cleared.
Terry
Title: Re: Stupid Questions :o
Post by: Darvince on July 20, 2016, 04:11:52 PM
Why do lows disperse ice and highs compact ice when the general wind flow of a low is towards the center and of a high is away from the center?
Title: Re: Stupid Questions :o
Post by: TerryM on July 20, 2016, 04:56:04 PM
Why do lows disperse ice and highs compact ice when the general wind flow of a low is towards the center and of a high is away from the center?
The coriolis force causes things in the Northern Hemisphere to turn to the right. Clockwise= compaction, CCW = dispersal.
Ekman pumping is related with the fastest spinning surface water moving away from the center to be replaced with deeper, warmer water.


Terry
Title: Re: Stupid Questions :o
Post by: ktonine on July 21, 2016, 04:38:09 AM
Okay, here's my "stupid question."

Why are the folks on the 2016 melting season thread tending to believe that this season is likely to not end up as a record?  At least it seems that a majority, especially of the longer-term posters, are saying that.

One of the reasons you see this is because people become infatuated with numbers, trends, and numerical comparisons based on previous years.  This will often lead to realistic projections, but it will rarely catch out of the ordinary events.

So, if one looks at extent or area one sees a set of numbers that don't indicate anything special.  OTOH, if one simply looks at a map of concentration like Univ. Bremen's AMSR2, then one sees an arctic that has been almost drawn-and-quartered.  One sees a central pack that has been decimated like no other year.  But though this is a special event - it still doesn't necessarily lead to a record low melt season.

Title: Re: Stupid Questions :o
Post by: Andre on July 31, 2016, 04:07:02 AM
Long time lurker here.

Have been following the forum for quite some time now and decided it was time to ask my first question. I am aware of people's criticisms of HYCOM, however, I still check it regularly.

I have recently noticed that there are two versions with significantly different current maps and forecasts. Could someone explain the difference to me and how they end up with such radically different results?

1)
https://www7320.nrlssc.navy.mil/GLBhycomcice1-12/arctic.html

2)
https://www7320.nrlssc.navy.mil/hycomARC/arctic.html

Seems to be about ARC vs GLB but would appreciate some insight. Thanks.
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on August 02, 2016, 05:31:14 PM
Why are we seeing a positive spike forming on DMI 80N?

I thought Latent Heat of Fusion was supposed to keep temps pegged around melting until the ice was gone???

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Focean.dmi.dk%2Farctic%2Fplots%2FmeanTarchive%2FmeanT_2016.png&hash=ed3bc1964e488b5d83cfae05c243a1bc)
Title: Re: Stupid Questions :o
Post by: jdallen on August 02, 2016, 05:58:00 PM
Why are we seeing a positive spike forming on DMI 80N?

I thought Latent Heat of Fusion was supposed to keep temps pegged around melting until the ice was gone???

Dump enough moisture and warm air into the arctic via cyclones, and that could overwhelm they typical buffering caused by phase change.
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on August 02, 2016, 06:09:02 PM
Why are we seeing a positive spike forming on DMI 80N?

I thought Latent Heat of Fusion was supposed to keep temps pegged around melting until the ice was gone???

Dump enough moisture and warm air into the arctic via cyclones, and that could overwhelm they typical buffering caused by phase change.

And that would be a first?
Title: Re: Stupid Questions :o
Post by: ghoti on August 02, 2016, 06:24:04 PM
Usually during the beginning of the freezing seasons people chime in "that's from latent heat released when ice forms" whenever there's an uptick in temperatures above the average. I'm wondering why the same people aren't suggesting it is a burst of water freezing up now...
Title: Re: Stupid Questions :o
Post by: jdallen on August 02, 2016, 06:35:41 PM
Usually during the beginning of the freezing seasons people chime in "that's from latent heat released when ice forms" whenever there's an uptick in temperatures above the average. I'm wondering why the same people aren't suggesting it is a burst of water freezing up now...
Physics... Because phase change pulls temperatures back towards freezing, not away from it.
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on August 02, 2016, 06:51:16 PM
So what would be the 'Tell' if open water began to exert an influence greater than the Latent Heat of fusion?

Would it not be a late season uptick in temps (as the ice proportion crashes and open water influences win out) followed by a long tail off ( as we saw in 2012) as the water sheds heat before refreeze?
Title: Re: Stupid Questions :o
Post by: jdallen on August 02, 2016, 07:06:21 PM
So what would be the 'Tell' if open water began to exert an influence greater than the Latent Heat of fusion?

Would it not be a late season uptick in temps (as the ice proportion crashes and open water influences win out) followed by a long tail off ( as we saw in 2012) as the water sheds heat before refreeze?
The only way that comes to mind would be temperatures consistently remaining above -1.8C.  You won't be able to see a "tell" I think, if SSTs are close to that.

The "tell" might be indirect also - for example if you examine net loss out of the atmosphere, and there is no import of heat from lower latitudes, but no freezing occurs, and temperatures remain flat at or near freezing.
Title: Re: Stupid Questions :o
Post by: be cause on August 02, 2016, 07:11:12 PM
Why are we seeing a positive spike forming on DMI 80N?

I thought Latent Heat of Fusion was supposed to keep temps pegged around melting until the ice was gone???

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Focean.dmi.dk%2Farctic%2Fplots%2FmeanTarchive%2FmeanT_2016.png&hash=ed3bc1964e488b5d83cfae05c243a1bc)

Hi GW .. whatever the cause it is not that unusual eg. 1987 had a strong spike at this time of year ..
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on August 02, 2016, 07:15:23 PM
Hi 'B'!

Yup but we know the pole was real solid back then?  so Jd's imports would explain those? as it does with the earlier in the year spikes?

It is just that we had Jim's secret santa pool early on in the season and the ice is pretty well mangles across the basin? I just got to wondering as to what DMI80N would do if more heat was being shed from around the ice than being held down due to LHF?
Title: Re: Stupid Questions :o
Post by: ktonine on August 03, 2016, 03:02:34 AM
Why are we seeing a positive spike forming on DMI 80N?

I thought Latent Heat of Fusion was supposed to keep temps pegged around melting until the ice was gone???

The Atlantic Sector has a significant amount of open water north of 80 degrees.  There are also very high temperature anomalies in these ocean waters. I suspect it's these ocean SST anomalies that account for the uptick in DMI temps.
Title: Re: Stupid Questions :o
Post by: ktonine on August 03, 2016, 03:37:46 AM
SST maps give a clue where the uptick is coming from.  I've approximated 80N in blue.

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fi256.photobucket.com%2Falbums%2Fhh197%2Fktonine%2Fcolor_anomaly_NPS_ophi0.jpg&hash=17f7a004f23ad305e4adff692614540c)
Title: Re: Stupid Questions :o
Post by: Dundee on August 08, 2016, 10:49:21 PM
After skimming half a dozen papers, I'm not finding what I am looking for.

Hypothetically, imagine a melt pond with 0C 100%RH air above, and radiative gain/loss in balance.

If the salinity of the pond is less that the ocean in contact with the ice beneath it, then the pond will be warmer than the seawater interface. This should result in heat flow down, freezing the pond and melting the base of the flow.

In real life, nothing is in balance, but late in the season when the internal temperature of the flow approaches melting equilibrium and solar input winds down, the same heat flow should occur. As melt ponds wrap up for the year, this could result in 10-15cm of bottom melt over and above that driven by external heat flows.

So my question is this - we pay a great deal of attention to the area of melt ponds, but I haven't seen anything on the volume of meltwater (and the bottom melt potential it represents late in the season). Has anybody come across the topic?
Title: Re: Stupid Questions :o
Post by: etienne on August 14, 2016, 10:49:31 AM
Hello,

I found an interesting article about the impact of the Pinatubo eruption (1991) on sea level rise.

http://www.nature.com/articles/srep31245 (http://www.nature.com/articles/srep31245)

Looks like the Pinatubo eruption had an impact on the earth albedo during at least 10 years.

On the https://ads.nipr.ac.jp/vishop/#/extent (https://ads.nipr.ac.jp/vishop/#/extent), when I select "yearly graph" than "draw linear fitting line from visible region", I get a graph where sea ice extend is above the trend from 1992 until 2004, exepted for 1995.

Don't know if this is of any interest.

Best regards,

Etienne 
Title: Re: Stupid Questions :o
Post by: Thawing Thunder on August 22, 2016, 03:45:53 AM

This is a really useful resource on density and freezing point at different salinities

http://linkingweatherandclimate.com/ocean/waterdensity.php (http://linkingweatherandclimate.com/ocean/waterdensity.php)

If I understood it right, then the salinity from the deeper water, once moved to the surface by the storm, avoids freezing not only because of its higher salinity, but also, and even more, by convection: Once the saltwater cools near its freezing point, it also reaches its highest density and sinks down into the ocean where it mixes with warmer water - the opposite effect appears with freshwater, where an upper layer freezes above the densest water (which in that case is 4 degrees "warm"). Is that correct?

But how does the arctic freeze every year despite that convection? Must the water cool near freezing point many meters down into the depth? Or does the surface freeze by shock? O did I get it all wrong?
Title: Re: Stupid Questions :o
Post by: Andreas T on August 22, 2016, 08:47:24 AM
You are spot on about density of sea water increasing as it cools to the freezing point (another place to look is https://nsidc.org/cryosphere/seaice/index.html (https://nsidc.org/cryosphere/seaice/index.html)).
Because ice crystals don't contain salt (it can be trapped in the form of concentrated salt water between ice crystals though) ice has lower density than sea water. Once ice forms it floats.
It is therefore possible to freeze the surface while water below the surface is still above its freezing temperature if the cooling is so strong it extracts heat from the water faster than it can move downwards driven by the (not so strong) density gradient.
For the cooling water to sink, warmer water below has to "get out of the way" and take its place at the surface which takes time and requires some lateral movement across the surface before that water gets away from the surface where heat transfer to the atmosphere occurs.
Title: Re: Stupid Questions :o
Post by: Thawing Thunder on August 22, 2016, 11:37:17 AM
Thank you Andreas. Now I have a basic idea of the whole mechanism. It's fun to begin to understand that strange world up there (and down there, too).
Title: Re: Stupid Questions :o
Post by: Iceismylife on August 22, 2016, 05:34:06 PM
...

But how does the arctic freeze every year despite that convection? Must the water cool near freezing point many meters down into the depth? Or does the surface freeze by shock? O did I get it all wrong?
Rate of cooling exceeds rate of convection.  Add a persistent GAC and convection may win.
Title: Re: Stupid Questions :o
Post by: 2phil4u on August 22, 2016, 06:24:38 PM
I have little knoledge about the arctic now, so i know some concepts.
But surely i cant understand it fully, because im a hobby observator.
My question.
Is this storm we saw important for the future ?
We have not hot summer and if ice will shaken and refreezing not this good, although temperatures are low and cloudy weather.
From a thermodynamical standpoint, if not this much energy is going in the N85 region, is some beaking ice maybe good for giving more heat to space ?
I readed in a wikipedia style paper, that if water is refreezing later, it also groth faster, because in total it will lose more energy to space before refreeze and so the bottom freezing is faster.
So are the next few weeks really important if you are not interested if the value is exactly like little below 2007 or something like that.
Title: Re: Stupid Questions :o
Post by: Sourabh on August 30, 2016, 11:15:32 AM
I have a question on dipole. Are there multiple kinds of dipole formation in and around arctic?  For example

    High pressure at the pole and low pressure in the surrounding areas (as I think was in 2007/2012)?
    Current one in which low pressure at the pole and high pressure in the surrounding areas?


Which kind of pressure arrangement would be more severe for ice? If this question has been answered before, please point me to that post/thread.

Thanks,
Sourabh
Title: Re: Stupid Questions :o
Post by: Neven on August 30, 2016, 02:03:11 PM
This is my opinion, not my knowledge:

First of all, it depends on the time period. And it also depends whether it's good/bad for the ice, or good/bad for sea ice extent/area. A classic Dipole anomaly, for instance, end of August, where the high sits on the American side of the Arctic, and the low over the Siberian side, will be bad for sea ice extent/area, due to compaction. But this perhaps helps thicken the ice, which would be good over all for the ice.

In June or July, however, extensive high pressure over the Arctic is really bad for the ice, as it causes widespread melt ponding/preconditioning.
Title: Re: Stupid Questions :o
Post by: dnem on September 01, 2016, 05:58:18 PM
i'm sure this has already been answered but why is there a mask directly over the pole?  Why can't satellites see there or estimate cover there?
Title: Re: Stupid Questions :o
Post by: LarsBoelen on September 01, 2016, 06:11:19 PM
That depends on which satellite data you look at: polar satellites pass over the poles several times a day and are the only ones with a clear view of the poles themselves. Satellites revolving round the equator or geostationary satellites have very shallow vision in the polar regions that may lead to that region being blacked out.
Satellites imaging in visual light of course are dependent on available light, so expect the North Pole to become black after September 21st (plus the blacked out region growing rapidly after that)
Title: Re: Stupid Questions :o
Post by: dnem on September 01, 2016, 07:13:04 PM
specifically Wipneus's maps in the Home brew AMSR2 thread.
Title: Re: Stupid Questions :o
Post by: Juan C. García on September 07, 2016, 04:36:48 AM
It is possible in nullschool to check how the wind was 24 hours or 48 hours ago? How can I do it?
Title: Re: Stupid Questions :o
Post by: Darvince on September 07, 2016, 06:43:42 AM
Yes. Click "earth" in bottom left corner, then on the Control row, press «
Title: Re: Stupid Questions :o
Post by: slow wing on September 07, 2016, 08:15:31 AM
It is possible in nullschool to check how the wind was 24 hours or 48 hours ago? How can I do it?
Yes.
1) Click on "earth"
2) at the "Control" line, click on "<<": once for 24h, twice for 48h.
Title: Re: Stupid Questions :o
Post by: slow wing on September 07, 2016, 08:25:41 AM
My stupid question, for the meteorologists:
At this time of year - i.e. near the end of the melt season - is a high pressure system in the Arctic basin helpful or hurtful for the area beneath it to freeze over?

On the one hand, the air near ground level might be a little warmer, as high pressure warms the air due to adiabatic compression.

On the other hand, the skies are more likely to be cloudless. At this time of year I might expect the sky to appear cold and a sink for thermal radiation.

So what is the actual situation?  ???
Title: Re: Stupid Questions :o
Post by: Juan C. García on September 08, 2016, 06:50:33 PM
It is possible in nullschool to check how the wind was 24 hours or 48 hours ago? How can I do it?
Yes.
1) Click on "earth"
2) at the "Control" line, click on "<<": once for 24h, twice for 48h.

Thanks slow wing!  :)
Title: Re: Stupid Questions :o
Post by: Adam Ash on September 09, 2016, 08:01:14 AM
Am I correct in detecting that when cyclonic dipoles form in the Arctic basin they frequently tend to have one end over high concentration ice pack (low pressure, I think) and the other end (usually high pressure) over clear(er) water?

It would seem reasonable to imagine that the dipole is acting as an energy pump hot to cold. 

Is it merely coincidence that the dipoles end up configured thus, or is the presence of warmer water at one end of the dipole and colder pack ice at the other actually a cause of the dipole formation and of its persistence, rather than an effect?
Title: Re: Stupid Questions :o
Post by: seaicesailor on September 09, 2016, 12:52:14 PM
Am I correct in detecting that when cyclonic dipoles form in the Arctic basin they frequently tend to have one end over high concentration ice pack (low pressure, I think) and the other end (usually high pressure) over clear(er) water?

It would seem reasonable to imagine that the dipole is acting as an energy pump hot to cold. 

Is it merely coincidence that the dipoles end up configured thus, or is the presence of warmer water at one end of the dipole and colder pack ice at the other actually a cause of the dipole formation and of its persistence, rather than an effect?
A very loose definition of dipole as a weather pattern should be a cyclone (a low) and an anticyclone (a high), side by side.
So maybe you want to clarify what you mean by "cyclonic dipole"
The high can be over ice pack or open water, the low too. So there are 4 different combinations.
For a more restrictive understanding of what Arctic dipole is, or what is understood in the forum at least (that evil dipole for the ice) is high somewhere in American side of Arctic and low somewhere in the Eurasian side of the Arctic, with large difference of pressure, preferably the high over Beaufort and the low over Laptev for evil minds, sustained for some days, because it pulls Pacific warm air into the Arctic (and possibly water thru Bering dragged by this air flow), it favors Beaufort clockwise surface drift, transpolar drift, and transport of ice toward Fram and the Atlantic.

About the relationship climate change - evil dipole: I heard of scientific studies that find a relationship of global warming/less Arctic sea ice with more frequent formation of this evil dipole. But I heard of others that find a relationship of global warming/less Arctic sea ice with stormier summers. Is drinking wine in moderate quantities good for health? Go figure.
Title: Re: Stupid Questions :o
Post by: CognitiveBias on September 09, 2016, 03:58:08 PM
Are there any forums dedicated to debunking the pseudo-scientific denier claims.  I'm specifically interested in the "Feet of Clay' series.
Title: Re: Stupid Questions :o
Post by: Neven on September 09, 2016, 07:38:05 PM
I've never heard of the Feet of Clay series, but Google "Skeptical Science".
Title: Re: Stupid Questions :o
Post by: Cate on September 09, 2016, 09:17:14 PM
I googled "Feet of Clay climate". WUWT shows up. Nuff said.
Title: Re: Stupid Questions :o
Post by: crandles on September 09, 2016, 09:34:41 PM
I googled "Feet of Clay climate". WUWT shows up. Nuff said.

or
Quote
Feet of clay: The official errors that exaggerated global warming – part 3
Guest Blogger / 3 days ago September 6, 2016
Part III: How the feedback factor f was exaggerated

By Christopher Monckton of Brenchley

Christopher Monckton. Nuff said.


But perhaps some people do want more. Not sure if this is the same stuff:

Quote
Summary of Part 1:  In his latest book, The Great Global Warming Blunder, Roy Spencer lashes out at the rest of the climate science community for either ignoring or suppressing publication of his research.  This research, he claims, virtually proves that the climate models used by the IPCC respond much too sensitively to external “forcing” due to changes in greenhouse gas concentrations, variations in solar radiation, and so on.  Instead, Spencer believes most climate change is caused by chaotic, natural variations in cloud cover.  He and a colleague published a peer-reviewed paper in which they used a simple climate model to show that these chaotic variations could cause patterns in satellite data that would lead climatologists to believe the climate is significantly more sensitive to external forcing than it really is.  Spencer admits, however, that his results may only apply to very short timescales.  Since the publication of his book, furthermore, other scientists (including one that initially gave Spencer’s paper a favorable review) have shown that Spencer was only able to obtain this result by assuming unrealistic values for various model parameters.
from
https://bbickmore.wordpress.com/2011/02/25/roy-spencers-great-blunder-part-1/

Title: Re: Stupid Questions :o
Post by: CognitiveBias on September 09, 2016, 10:29:16 PM

Neven, I will definitely add Skeptical Science to my reading list.  BTW, your typepad site was my first intro to the Arctic Ice/climate topic that I now find so fascinating.  Thank you!

Cate and crandals,  thanks for the responses as well.  'Nuff said' is all it takes for those that hold Watts and his type in contempt.  Here in ultra-conservative suburbs of Dallas TX, I am often in the minority defending against his type of pseudo-scientific efforts and other types of magical and conspiratorial thinking.  I was just looking for resources that might help.

 Thanks again!
Title: Re: Stupid Questions :o
Post by: Cate on September 10, 2016, 12:32:21 AM
CognitiveBias, my apologies if my post came off as brusque, as that was not my intention!

If you are looking for info to refute deniers,  may I recommend Robertscribbler's blog as an excellent starting point for the general reader. The discussion is civil, informed, and focused, with no denial and no doom-saying allowed, and the links---both the blogger's as well as those posted by readers---are solid.

robertscribbler.com
Title: Re: Stupid Questions :o
Post by: CalamityCountdown on September 10, 2016, 04:56:36 PM
Can the impact of an El Nino on Arctic Sea Ice melt be calculated with a reasonable degree of confidence? And is the end of the “Godzilla” El Niño a significant factor in predicting the likelihood of a lower minimum for extent/area during the 2017 melting season than the minimum we are on the verge of seeing for 2016?   
Title: Re: Stupid Questions :o
Post by: Adam Ash on September 11, 2016, 10:18:56 AM
A very loose definition of dipole as a weather pattern should be a cyclone (a low) and an anticyclone (a high), side by side....

Thanks SeaIceS.  Yes the dipole I was thinking about was a cyclone+anti-cyclone pair, as they seem to be capable of creating more havoc. 

I guess what I was wondering was to what extent the presence of these structures is a Cause and what is an Effect of the prevailing ice conditions?  With the increasing open sea water surface one could imagine more and/or stronger energy-moving structures occurring over the polar region.
Title: Re: Stupid Questions :o
Post by: seaicesailor on September 11, 2016, 11:56:18 AM
A very loose definition of dipole as a weather pattern should be a cyclone (a low) and an anticyclone (a high), side by side....

Thanks SeaIceS.  Yes the dipole I was thinking about was a cyclone+anti-cyclone pair, as they seem to be capable of creating more havoc. 

I guess what I was wondering was to what extent the presence of these structures is a Cause and what is an Effect of the prevailing ice conditions?  With the increasing open sea water surface one could imagine more and/or stronger energy-moving structures occurring over the polar region.
Yes there are scientific studies about the same, not that I understand them though.
I wouldnt be surprised that this pattern has been happening for ages only that now it blows warmer air over thinner air. But this is stuff for scientists to unravel I guess
http://scholar.google.es/scholar_url?url=https://deepblue.lib.umich.edu/bitstream/handle/2027.42/94959/grl25555.pdf%3Fsequence%3D1%26isAllowed%3Dy&hl=en&sa=X&scisig=AAGBfm1e6_zLk0rvGnJkED9a6t0QGS4kHw&nossl=1&oi=scholarr&ved=0ahUKEwi47Z6thofPAhWJthoKHaHGAuoQgAMIGigAMAA (http://scholar.google.es/scholar_url?url=https://deepblue.lib.umich.edu/bitstream/handle/2027.42/94959/grl25555.pdf%3Fsequence%3D1%26isAllowed%3Dy&hl=en&sa=X&scisig=AAGBfm1e6_zLk0rvGnJkED9a6t0QGS4kHw&nossl=1&oi=scholarr&ved=0ahUKEwi47Z6thofPAhWJthoKHaHGAuoQgAMIGigAMAA)
Title: Re: Stupid Questions :o
Post by: binntho on September 12, 2016, 08:35:39 AM
A stupid question, perhaps, and definitely off topic but I'm hoping some of the very clever people on this forum can help me. For some years now I've been wanting to find something that shows monthly and annual precipitation anomalies, particularly for the Mediterranean where I live, but also for the whole world. Something similar to the monthly temperature anomalies from NASA and others is what I had in mind. Has anybody ever come across something like that?
Title: Re: Stupid Questions :o
Post by: ruffed on September 12, 2016, 09:52:05 AM
Try This for Australia.

http://www.bom.gov.au/climate/change/?ref=ftr#tabs=Tracker&tracker=timeseries (http://www.bom.gov.au/climate/change/?ref=ftr#tabs=Tracker&tracker=timeseries)
Title: Re: Stupid Questions :o
Post by: charles_oil on September 12, 2016, 09:52:11 AM
Bin - try your national meteo office / bureau for archives.  Here in France you can find online historical data for your own location & should be able to check between two world cities as well.
http://www.meteofrance.com/climat/meteo-date-passee?lieuId=060880&lieuType=VILLE_FRANCE&date=01-09-2016 (http://www.meteofrance.com/climat/meteo-date-passee?lieuId=060880&lieuType=VILLE_FRANCE&date=01-09-2016)
I am sure they hold graphical / tabular historical data too.
Title: Re: Stupid Questions :o
Post by: Tor Bejnar on September 12, 2016, 03:17:17 PM
Binntho:
Try looking around the NOAA Global Precipitation Climatology Centre site (http://www.esrl.noaa.gov/psd/data/gridded/data.gpcc.html).  For example, the left menu has a 'plotting' option.  I found a combination of data set and variables options to give a plot of precipitation anomalies of the Mediterranean area (http://www.esrl.noaa.gov/psd/cgi-bin/GrADS.pl?dataset=GHCN+version+2+Gridded+Land+Precipitation+Dataset&DB_did=156&file=%2FDatasets%2Fghcngridded%2Fprecip.mon.anom.nc&variable=precip&DB_vid=3072&DB_tid=48066&units=mm&longstat=Anomaly&DB_statistic=Anomaly&stat=&lat-begin=20N&lat-end=50N&lon-begin=10W&lon-end=60E&dim0=time&year_begin=1900&mon_begin=Jan&year_end=2015&mon_end=May&X=lon&Y=lat&output=plot&bckgrnd=black&use_color=on&fill=lines&cint=&range1=&range2=&scale=100&submit=Create+Plot+or+Subset+of+Data):
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fwww.esrl.noaa.gov%2Fpsd%2Ftmp%2Fgrads%2F199.73.152.177.255.7.12.31.png&hash=eb66680ac22ed7e19e62fc86d7e907f7)
This doesn't mean I know what the plot means!
Title: Re: Stupid Questions :o
Post by: binntho on September 12, 2016, 04:04:50 PM
Thanks all for the replies! I've had a look at the different sites, and I think the one Tor pointed me to is exactly what I've been looking for!
Title: Re: Stupid Questions : Minimum Extent 4 Days Before Average?
Post by: CalamityCountdown on September 12, 2016, 05:36:20 PM
Based on the information showing on the NSIDC site http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/, (http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/,) it appears that the minimum extent for the ASI 2016 melting season occurred about 4 days earlier than average, based on the 5 day average extent versus 1981 - 2010.  (assuming 9/10 holds as the minimum). Given all the open water, is that fact that minimum extent occurred a few days earlier than average a meaningful event (based on NSIDC and assuming I'm reading the data correctly)
Title: Re: Stupid Questions :o
Post by: Adam Ash on September 15, 2016, 11:55:27 AM
Over in the Polls Pmt111500 mentioned among preferred options for the post-1M sqkm ice era that by then there would not be a  '...marine Arctic biotope anymore'.

A lot of Arctic marine life would be impacted by even the recent reductions in surface ice area, but are there any estimates of mortality among polar bears when an area like the Wrangle Arm is separated from the main pack, and then goes poof?

I know PBs can swim vast distances, but I doubt they could have made it from the Wrangle Arm to anywhere above water before they ran out of energy supplies and perished from starvation mid stroke.
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on October 11, 2016, 09:34:02 AM
Hi Guys!

How did Barrentz move from ice covered to ice part ice free over winter during the noughties?

I'm only wondering this since the 'October slowdown' in ice re-growth, could it be signalling a move to part covered over in Beaufort?

Has Barrentz ,via open water processes, now become even more unlikely to see ice now over winter and if the answer is 'yes' then will the extension of the open water ( spring and autumn) across Beaufort make it less likely to see ice forming there?

Ta in advance!
Title: Re: Stupid Questions :o
Post by: oren on October 11, 2016, 09:57:33 AM
I doubt it, the Beaufort is too cold and isolated during winter for ice not to form. The Barents gets warm water from the Atlantic, I believe this causes a fundamental difference.
I tried looking for a chart of winter max and summer min for the Beaufort, this could show the answer statistically. My gut feeling is that the Beaufort has transitioned to an ice-free state during summer, but that winters have almost full ice-cover except where polynyas form due to ice movement.

Edit: found it through Neven's blog, I knew it was there somewhere. This is area, not extent.

As you can see, the Beaufort is maxed out at winter but has been reaching zero and near zero more and more in the summer, by now it's quite consistent. I believe the ice-free season may be lengthening, but in deep winter it will still be ice-covered.
The Barents has always had a seasonal ice cover, but in the last decade winter cover is disappearing, now it's less than half what it used to be.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Farctic.atmos.uiuc.edu%2Fcryosphere%2FIMAGES%2Fregion.all.anom.region.11.jpg&hash=fb7e3c49aeac68e3f0747274da91afe2)
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Farctic.atmos.uiuc.edu%2Fcryosphere%2FIMAGES%2Fregion.all.anom.region.6.jpg&hash=8d7ca2b7876c365fc07f76dd76e5e594)
Title: Blue Ocean
Post by: Forest Dweller on November 04, 2016, 03:43:58 PM
Hello all from a new member, thought i'd start here :)

I have a question concerning Blue Ocean Event.
Not the effects on the global weather etc, but a 2-prong question concerning before and after sea ice behaviour;

Before:
I gather melting of the sea ice will happen at accelerated pace.
Supposedly the last sea ice will disappear very fast, poof it's gone.
Any more specific models or study on this?
At what point of total sea ice volume left perhaps, do we really expect things to unravel
exponentially?

After:
I hear people say how after the first blue ocean in the Arctic, it will take 10 years of
refreezing less and less before finally in winter even nothing will remain.
Really???
Watching the current 2016-2017 refreeze so out of whack this seems hardly believable.
Add in some feedback loops...to a layperson i cant imagine 10 years of refreeze happening.
Feels more like we'd be lucky to have 1 winter with ice after that or 2 perhaps...

Any thoughts welcome.
Title: Re: Stupid Questions :o
Post by: P-maker on November 04, 2016, 06:25:22 PM
Hello Forest Dweller

Welcome to the Forum. You’ve certainly got some nerve to walk in here and pose questions like that:

1)   You are not a member, you are primarily a contributor here
2)   If you wish to read about Blue Ocean Events in the Arctic, please start here: https://www.researchgate.net/profile/Koji_Yamazaki2/publication/308009569_On_the_atmospheric_response_experiment_to_a_Blue_Arctic_Ocean_Climate_Response_to_Blue_Arctic_Ocean/links/57d8a0aa08ae5f03b498608f.pdf?origin=publication_list (https://www.researchgate.net/profile/Koji_Yamazaki2/publication/308009569_On_the_atmospheric_response_experiment_to_a_Blue_Arctic_Ocean_Climate_Response_to_Blue_Arctic_Ocean/links/57d8a0aa08ae5f03b498608f.pdf?origin=publication_list)
3)   Concerning your ”Before” questions, this has been a long-standing debate both at the Blog and at the Forum. Too difficult to summarize in a few sentences.
4)   Concerning your “After” questions, I’ll have a go at it below.

I don’t like the concept of “Blue Ocean Event” because it will not be anything like an event, which A) may  suddenly occur one day, B) be described in the media amongst the ordinary news feed, and then C) pop up again later one day.

The colour “Blue” may not be an appropriate description, since open water in the Arctic may take all kinds of colours to the naked eye. In addition, all kinds of satellites may depict the whole electro-magnetic spectrum in all kinds of odd colours afterwards. Maybe it would be more appropriate to talk about an “Open Ocean Signal”. I foresee all kinds of blue-green algae adding to the complexity of the palette as we go along.

Concerning the “Ocean” part, I – and others for that matter – have foreseen that the central Arctic basin may be ice-free sooner than most people here expect. On the contrary, we are still uncertain as to the amount/volume/level of ice production in the marginal seas during winters in the future, and hence the advection of these ice volumes into the Arctic Ocean afterwards. 10 years of marginal seas refreezing may not be totally out of the question. At least 10 years of catastrophic devastation of the Greenlandic tidewater glaciers is highly likely after the date. This exodus of brash ice – this armada of icebergs – will in itself help to keep up both extent and area in the seas adjoining the ice sheet.

It is not going to be an “Event” of a kind you may be used to. I’ll spare you the details of the consequences at this time, but I hope you will find the time to look through some of the threads in the “Consequences” part of the Forum over the weekend and then come back, when you have made up your mind.

Title: Re: Stupid Questions :o
Post by: Forest Dweller on November 05, 2016, 05:33:43 PM
Hi P-Maker,

I meant no offence and did try to read relevant topics, there is a lot out there.
I would agree already the "event"is not a correct description at all.
Thank you for your perspective on the "after" and also the "blue".
This would make a lot of sense indeed.

Thanks for the link which i will certainly check out.
As the other points you mentioned, and perhaps get back later as you suggest.

Title: Re: Stupid Questions :o
Post by: oren on November 05, 2016, 08:30:46 PM
Welcome Forest Dwelller! The first post is really the hardest. It's a great forum, you'll learn a lot and I'm sure will contribute as well over time.
Regarding your question, it is definitely not stupid but is too large and unknown, there is no easy answer but here's a summary of my own thinking:
Leading up to a "relatively ice-free Arctic in late summer" will probably be a season of weak ice to start with, increased melt due to weather and incoming heat from the periphery, and finally the defined mark of "less than 1 million square kilometers of sea ice extent" considered "ice-free Arctic". Probably some ice will be left somewhere next to Ellesmere Island, the CAA or Greenland, and here and there. An acceleration towards the "end"  is possible because of thinner ice going poof, but on the other hand this will happen towards the end of the melting season, when melt rates are much lower.
As to after the "event", you should not be surprised to see the Arctic Ocean wholly or partially refreezing during winter for quite a long time to come. It generally takes -10oC to effectively freeze sea water. The central Arctic at midwinter goes to -35oC. Even with all kinds of warming and feedbacks, water vapor, waves and storms, CO2 etc., some part of the Arctic during some part of the winter will reach the required temps and refreeze. Bear in mind the central Arctic is currently "ice-full" during 8 months of the year, while many peripheral seas are ice-full for 5 months. Even with a longer ice-free period, you might still get to full extent, just for a shorter time. I expect the same to happen this year as well. There is a good probability though that after the winter refreeze following the "ice free" end of season, the next summer will find it easy to reach the same ice-free state again, although there have been strong arguments as to why even that is not expected (the "Slow Transition" theory).
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on November 07, 2016, 12:36:39 PM
Hi Forest Dweller!

This past year has altered my views on the B.O.E.
In the past I thought it would take another 'perfect melt storm synoptic' year over a pack like we went into this summer with to have a chance of such a thing occurring but not now! After seeing the repeated fragmentation events over winter and then the early start to melt season I began to think that pre conditioning the pack was just as important as the weather was?
I now think of 'cold transition' and 'warm transition'. This year showed us what a cold transition would be like with a very fragile pack just not having it in it to survive an 'average' melt season. the 'warm transition' would be the return of the perfect melt storm synoptic and so could lead to either an Aug melt out for a weak pack or an early Sept melt out for a more substantial pack?
This year we are seeing our last, best ice, sat over Fram/Barentsz and so likely to be lost over the coming winter ( being replaced inside the pack with late formed first Year ice?) so we may end up with a pack similar to the one we will have after the first B.O.E. If this happens then a cold transition is possible next year (if we see another warm and disruptive refreeze season) and a very early B.O.E. if we see a return of the Perfect melt storm synoptics over the duration of melt sweason!
Title: Re: Stupid Questions :o
Post by: CalamityCountdown on November 11, 2016, 12:15:45 PM
According to nsidc.org "Ice extent is particularly low on both sides of the Antarctic Peninsula. The rapid early reduction in sea ice cover in this region may create favorable conditions for the break up of the eastern Peninsula ice shelves at the end of austral summer. Similar sea ice trends and weather conditions were present during the spring seasons preceding past ice shelf retreats (e.g., 2001 to 2002)".  Raises the question of what is the worst case scenario for this year's Antarctic melt season? And how can I give this question an arctic sea ice slant so that it is at least marginally on topic?
Title: Re: Blue Ocean
Post by: crandles on November 11, 2016, 01:12:29 PM
Hi and welcome to the forum.


Before:
I gather melting of the sea ice will happen at accelerated pace.
Supposedly the last sea ice will disappear very fast, poof it's gone.
Any more specific models or study on this?
At what point of total sea ice volume left perhaps, do we really expect things to unravel
exponentially?


While some people seem to think this, I think it is a small minority of experts in the relevant field perhaps just Wadhams who is easy to dismiss as 'gone emeritus'. Reading this forum gives the impression it is much more mainstream.

If you look at plots of lots of models you should see that pretty much all models show a slowing of the rate of decline as zero ice in September is approached:

(https://robertscribbler.files.wordpress.com/2013/12/ipcc-global-climate-model-sea-ice-melt-projections-for-extent-trend-in-black.jpg)

So I would say all the models and studies deny it.

I think maybe in the region of 100 years would be a more mainstream view of how long between ice free September and ice free year round. With no sunshine and no ice as insulation, the ocean can lose enormous quantities of heat. There would have to be very thick clouds to reduce the rate of heat loss. Equable climates happened somehow and we are not sure how let alone know enough about the transition process. I would guess the transition time would be long with the ocean slowly gaining heat but that is only a guess and I cannot rule out a much shorter transition time.
Title: Re: Stupid Questions :o
Post by: Archimid on November 11, 2016, 02:14:30 PM
Thanks for that graph. When I look at that graph I don't see the models being right. What I see is observations well below the mean and median of the models, indicating an acceleration in extent reduction not observed in the models. I also see several models that project ice free within 10 years.

Another thing that comes to mind is that these are sea ice extent models. Extent hides so many nuances that I don't think it is a good measure of the state of the ice. Are there any models of Arctic sea ice volume? How are those stacking up with reality? How about ice age. Are there any models for ice age? If so, how do they stack up to reality?

I also fear that many of these models assume that the year after an ice free arctic the temperature of the atmosphere above the arctic will be -40C. This freezing season clearly show that the arctic temperatures can be much higher than they have ever been before. How does this fact affect the models? My bet is that the bounds are significantly altered.




Title: Re: Stupid Questions :o
Post by: johnm33 on November 11, 2016, 02:21:24 PM
Forest Dweller Welcome,"At what point of total sea ice volume left perhaps, do we really expect things to unravel exponentially?" good question, made me think anyway. I think this graph from Jim Pettit answers it. Looking at the approaching equality of max possible melt, and seasonal max, soon.
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fiwantsomeproof.com%2Fextimg%2Fsiv_annual_max_loss_and_ice_remaining.png&hash=abd6be9e6aae50f91aecf6b77a2ce574)
  Much depends on where the thick ice is,in any year, it inhibits the loss of meltwater and the fresh water input from Siberian rivers, and resists the inflow of Atlantic waters, but only when it's on the coast of the CAA. Once free of that coast it's movement probably adds to the stirring of warm deeper layers. This year the thicker/older ice is spread out but it seems there's enough on the coast, for now. http://svs.gsfc.nasa.gov/4510 (http://svs.gsfc.nasa.gov/4510)
Title: Re: Stupid Questions :o
Post by: Archimid on November 11, 2016, 02:45:17 PM
https://www.arcus.org/sipn/sea-ice-outlook/2016/august (https://www.arcus.org/sipn/sea-ice-outlook/2016/august)

It contains an analysis of models vs observed results of arctic sea ice.
Title: Re: Stupid Questions :o
Post by: oren on November 11, 2016, 02:56:45 PM
According to nsidc.org "Ice extent is particularly low on both sides of the Antarctic Peninsula. The rapid early reduction in sea ice cover in this region may create favorable conditions for the break up of the eastern Peninsula ice shelves at the end of austral summer. Similar sea ice trends and weather conditions were present during the spring seasons preceding past ice shelf retreats (e.g., 2001 to 2002)".  Raises the question of what is the worst case scenario for this year's Antarctic melt season? And how can I give this question an arctic sea ice slant so that it is at least marginally on topic?

A very good question. I suggest you post this in the appropriate thread, Sea Ice Extent around Antarctica. Best if you include the link for the nsidc article you are referring to.
http://forum.arctic-sea-ice.net/index.php/topic,1759.0.html (http://forum.arctic-sea-ice.net/index.php/topic,1759.0.html)

As this forum deals with Antarctica as well as arctic sea ice, your question is definitely on topic.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on November 11, 2016, 03:24:54 PM
I love both of these graphs and it is clear there is an accelerating trend visible that the models are not capturing. However these graphs track how rapidly we are heading to a seasonally ice free Arctic. I would not be surprised if this were to happen quite soon, perhaps within 10 years. I would also not be surprised if it took much longer.

These graphs do not, however, say anything about a year long ice free Arctic. Years ago I proposed a new measure that might be useful to track. This would be the annual spread between minimum ice extent (perhaps area as well) and maximum ice extent. The minimums are dropping quite rapidly and this drop is accelerating. The maximum extent is not dropping as quickly so that this seasonal spread between minimum and maximum is actually increasing. I suggested that we call this metric the "Bifurcated Intra-annual Chryosphere Oscillation Trend" (BICOT), also known as "Baby Its Cold Out There".  ;)

It is true that winter temperatures over the Arctic are increasing during the winter. The anomalies as I type are spectacular. The actual temperatures are still quite adequate to cause a rapid freeze (less so now but still rapid). For the winter temperatures to finally reach a point where freeze does not occur in the long Arctic night would require, I believe, a phase change in global climate. I am not sure what that mechanism would be but I am very intrigued by the theory of our three atmospheric cells transitioning into a single cell as the cause. Some here have postulated that this transition to one cell would first move to two cells. I don't believe this is the case. I think the transition is an immediate transition from three to one.

Why this quick transition to one cell? If you look at the model below and the behavior of the Hadley, Ferrel and Polar cells, the cell that will disappear is the Ferrel cell. We will then have a single cell with warm air rising at the equator, traveling all of the way to the pole and sinking over the pole. The trade winds are tied directly to the three cells and would be wildly altered. It would seem that they might similarly set up in a manner that would bring very warm, moisture laden, tropical atmosphere all of the way to the Arctic, a very stormy Arctic indeed.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on November 11, 2016, 03:40:22 PM
So, how close are we to this phase change? I have no idea. We know the Hadley cell is expanding and the Polar Vortex is breaking down more frequently, flooding the mid latitudes with cold polar air. Is this evidence of us approaching this transition? When it happens, there is no going back. The impact on northern hemisphere climate will be permanent from our time limited human perspective.

What is really interesting is that the paleo record suggests this transition to an equable climate can occur in the northern hemisphere while the frozen Antarctic ice sheet will maintain a three cell circulation in the southern hemisphere.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on November 11, 2016, 04:13:21 PM
The two cells in question would be permanently cloudy arctic with great arctic cyclone type depression moving about, and the hadley cell would expand to cover northern mediterranean, southern US and the whole of India and large parts of southern China, from these the dry air of greatly expanded desert belt would flow northward towards the depression (wacc+hadley expansion). I cannot say what parts of the desert edges would get monsoonal rains generated by trade winds and how much rain would be there (if at all). Nh 1-cell system and Sh 3-cell system would have been in Pliocene, was it? 15 m of sea level rise from total collapse of Greenland ice sheet and partial collapse of WAIS, i think compared to current times. I don't know which is better, I'm fairly certain I'm dead before either gets fully implemented.
Title: Re: Stupid Questions :o
Post by: oren on November 11, 2016, 04:28:08 PM
As the cells discussion is deepening, it should be better to move it to an existing or a new thread rather than be clogged here in Stupid Questions.
Title: Re: Stupid Questions :o
Post by: crandles on November 11, 2016, 05:54:16 PM
Thanks for that graph. When I look at that graph I don't see the models being right.

Absolutely, many of them are miles out. So don't trust them on the level of ice.

But what they do show is widespread agreement on the shape - this is an acceleration in the rate of loss of sea ice but then there is deceleration in the rate as zero ice is approached.

I suggest it is sensible to trust the models where there is widespread agreement but don't trust them when there isn't.

The models that show ice free by 2025 have nowhere near enough ice for last two or three decades so should be regarded as not trust worthy.

The whole argument for a rapid disappearance seems to rest on seeing a sudden acceleration in the observed rate of decline and simply assuming that continues. This flies in the face of the models saying that can tend to happen for a while but also tends to reverse to a deceleration in the rate of decline.

Title: Re: Stupid Questions :o
Post by: Archimid on November 11, 2016, 06:52:29 PM
I'm hesitant to post again, because this is the stupid question threads. OP's question was not stupid, just hard to answer and controversial. Funny thing is that a question like that would have been dismissed at any serious scientific forum.

Quote
But what they do show is widespread agreement on the shape - this is an acceleration in the rate of loss of sea ice but then there is deceleration in the rate as zero ice is approached.

I agree that most models that can be made out on that graph have an agreement in shape within the models. However the shape they agree on is potentially different from the shape of observations. Recent observations seem to approach the opposite inflection point of models. Models inflect up, observation seem to be inflecting down. I admit more years are needed to even determine an inflection, but in my understanding, the physics are there to make it happen.

Quote
The models that show ice free by 2025 have nowhere near enough ice for last two or three decades so should be regarded as not trust worthy.

Yep, but that does not mean that we should ignore emerging trends. The emerging trend since 2007 is ominous and getting worse as we type.
Title: Re: Stupid Questions :o
Post by: plinius on November 11, 2016, 07:09:10 PM
Ahem, Shared-Humanity - I am not sure where you get your physics of all atmospheric cells merging, but it is in truth very simple. The size of the Hadley Cell is given by where the subtropical jet gets too fast to remain stable (the air from the ITC going northward achieves a large eastward speed), and there is no way at current earth rotation of stretching that thing even anywhere close to the pole. So, one could debate about disrupting the central polar vortex, but well, in the northern hemisphere it has never been that stable anyway (see also sudden stratospheric warming events). So, quite a useless discussion.

@Archimid: I am not sure about the downward acceleration in observations. Yes, for the past 30 years or so, and fully agreed that the ice models were too tame on that, but exactly now we are entering a new regime, where actually wide open areas of water give some negative feedback on the annual volume budget - they freeze over with ~1.5 m or so of ice in the winter. To me it looks like winter duration is still too long to break this.
So the conditions to ask about are:
- Do we have any space for feedbacks that could reduce the amount of winter freeze to a level where the arctic ocean can accumulate heat in a runaway by early spring openings.
- Are the feedbacks that drive this larger than the current negative feedback on the energy budget by having less insulation from ice on top of the ocean (and if you look up for e.g. Langlaufer's papers, at least to me it looks like on a simplified view, we are still quite a way from that point).
- Is the possible equilibrium of a summer-ice-free arctic ocean possible by drift/currents earlier than reaching this point? (which seems possible to me, especially if there is some more salinity and atmospheric circulation feedback on the European edge).
Title: Re: Stupid Questions :o
Post by: Ice Shieldz on November 11, 2016, 11:38:51 PM
Does anybody know what causes the signal of a band of warmer water to show up around the ice pack in nullshool?

Edit:  Oh it seems those are the currents - although in many instances the heat doesn't line up with where the currents are occurring.
Title: Re: Stupid Questions :o
Post by: Archimid on November 11, 2016, 11:50:14 PM
Ahem, Shared-Humanity ... So, quite a useless discussion.

could you please refrain from such language? I'm trying to stay as civil as possible about a matter I believe to be of life and death for me and everyone else alive.  You keep using words to make this argument seem irrelevant or unimportant.

Quote
@Archimid: I am not sure about the downward acceleration in observations.

Please see the arctic sea ice volume anomaly and trend here :
http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.1.png (http://psc.apl.uw.edu/wordpress/wp-content/uploads/schweiger/ice_volume/BPIOMASIceVolumeAnomalyCurrentV2.1.png)

That's downward acceleration.

Quote
Yes, for the past 30 years or so, and fully agreed that the ice models were too tame on that,


I would say that after 2007 the long range models have consistently underestimated the melting but ok.

Quote
but exactly now we are entering a new regime, where actually wide open areas of water give some negative feedback on the annual volume budget - they freeze over with ~1.5 m or so of ice in the winter. To me it looks like winter duration is still too long to break this.

My bet is that this high temperatures are only the beginning. winters will keep getting progressively weaker as the ice disappears. Once a tipping point minimum arctic sea ice occurs (it could've happened this year)then the state of the arctic (and the world) changes and the warming winters rapidly accelerate. That's the inflection point.

Title: Re: Stupid Questions :o
Post by: Pmt111500 on November 12, 2016, 04:54:07 AM
Quote

: plinius  November 11, 2016, 06:09:10 PM
Ahem, Shared-Humanity ... So, quite a useless discussion.


could you please refrain from such language? I'm trying to stay as civil as possible about a matter I believe to be of life and death for me and everyone else alive.  You keep using words to make this argument seem irrelevant or unimportant.


Umm, it so happens QBO just flipped, and that shouldn't have happened either if we're to follow old textbooks. The subtropical jet may well stay where it is in the stratosphere even in equable climate, for all I care.

The movement and expansion of the desert belt in that scenario could possibly generate new areas for monsoonal rains so there's that hope for some of the areas affected.
Title: Re: Stupid Questions :o
Post by: Sleepy on November 12, 2016, 08:13:08 AM
@Archmid; I feel no need to argue with anyone in here but there is a history to this issue on this forum, and what plinius wrote above is correct.
Quote
"The size of the Hadley Cell is given by where the subtropical jet gets too fast to remain stable (the air from the ITC going northward achieves a large eastward speed), and there is no way at current earth rotation of stretching that thing even anywhere close to the pole."
This was up in the freezing seasons thread when someone claimed an observation of the Hadley Cell expansion into the Arctic. In my comment there I gave a link to an older thread:
http://forum.arctic-sea-ice.net/index.php/topic,1107.msg43463.html#msg43463 (http://forum.arctic-sea-ice.net/index.php/topic,1107.msg43463.html#msg43463)
Read the first linked paper there:
http://empslocal.ex.ac.uk/people/staff/gv219/classics.d/persson_on_coriolis05.pdf (http://empslocal.ex.ac.uk/people/staff/gv219/classics.d/persson_on_coriolis05.pdf)
It explains the history and also provides an answer to why so many still gets this wrong. I'll just quote the last section.
Quote
Correspondents to the American Journal of Physics have noted that university students
cherish naïve, Aristotelian ideas about how and why things move. For example, many students
believe that forces keep bodies in motion and, conversely, that in the absence of forces bodies are at rest.35 There are no reasons to assume that students in meteorology are immune to this
“Aristotelian physics” as it has been called. The crux of the matter does not lay in the
mathematics but in our common senses which are still Aristotelian.
Finally adding a graph depicting how flawed our common senses can be, can you sense the speed you are travelling at right now?
Title: Re: Stupid Questions :o
Post by: S.Pansa on November 12, 2016, 09:47:12 AM
This site (https://www.seas.harvard.edu/climate/eli/research/equable/index.html) might provide some further useful infos w.r.t. what could have caused the various equable climates during earths history (see the theories section (https://www.seas.harvard.edu/climate/eli/research/equable/theories.html)).

One of those theories - from Brian Farrell - is about the Hadley cell and the possible mechanisms, under which it could expand to the poles. Some snippets:

Quote
... Eventually, the zonal velocity is so strong that the particle stops moving poleward and only travels to the east. At this latitude, air sinks, and then to close the loop, it returns to the equator along the surface. Therefore, because of the conservation of angular momentum, Hadley Cells exist only from the equator to the mid-latitudes. ...

This scenario holds as long as the initial assumptions are valid. Brian Farrell, however, argues that the assumptions are not accurate for equable climates and that during equable climates, angular momentum is not conserved in poleward moving particles (1990). ...

Based off of Venus' atmosphere's behavior, Farrell argues that another way to extend the Hadley Cells would be to increase the height of the tropopause. ...

While each of these alterations [stronger angular momentum sinks & increase in the tropopause height] to the atmosphere would extend the Hadley Cells, Farrell found that a combination of the two effects was necessary to make his model's results agree with proxy data from equable climates. ... The results reveal that as tropopause height and friction increase, the EPTD decreases. ... As a result, Farrell's theory seems to be a reasonable explanation for equable climates. ...

The main problem is that Farrell does not provide any explanation for why angular momentum sinks would have become stronger during the Cretaceous and the Eocene. He provides a few examples of potential momentum sinks: "small scale diffusion..., cumulus momentum flux..., gravity wave drag..., and the net westward force arising from potential vorticity mixing by large scale waves" ... This lack of information in the argument makes the theory harder to accept, and until this portion of the argument is explored in greater depth, Farrell's theory cannot be accepted as the correct explanation of equable climates.

For more details see the tab "Hadley Cell" (https://www.seas.harvard.edu/climate/eli/research/equable/hadley.html).
As the References does not extend beyond 2010, however, I do not know if this theory has still some value.
Title: Re: Stupid Questions :o
Post by: Sleepy on November 12, 2016, 10:11:49 AM
Which is exactly the same source and link that spurred to my comment that I linked to above, from January 2015.
Another of the comments I got from Anders Persson back then was (freely translated) this: The tropopause has, unlike what some authorities claim, very little, if anything, to do with this. It doesn't even have a material surface.
Title: Re: Stupid Questions :o
Post by: S.Pansa on November 12, 2016, 11:57:35 AM
So for someone who is way out of his depth here: Is Persson the go-to guy for these matters? And is the controversy about what caused equable climates on earth resolved now?

A quick research did not really give me a satisfying answer.

According to this paper from Lee, 2014 (http://www.meteo.psu.edu/~sxl31/papers/Lee_31-43.pdf), the controversy is still ongoing, at least until recently (p 33, 34).
Quote
... Until  recently,  proposed  mechanisms  on  equable  climates that have considered poleward heat transports include a Hadley cell which occupies the entire hemisphere (Farrell, 1990), an enhanced poleward oceanic heat transport (e.g., Barron  et al ., 1993; Sloan  et al ., 1995), and an intensification of the thermohaline circulation due to driving by tropical cyclones (Sriver and Huber, 2007; Korty  et al ., 2008). There are other proposed mechanisms  that  do  not  involve  poleward  heat  transports.
These  include  a  convection-cloud  radiative  forcing  feedback (Sewall and Sloan, 2004; Abbot and Tziperman, 2008a, b), a vegetation-climate  feedback  (Otto-Bliesner  and  Upchurch,
1997; DeConto  et al ., 2000), and decreased cloud reflectivity due to a reduction in the number of cloud condensation nuclei(Kump and Pollard, 2008). But again, as was discussed above,
an equilibrium climate requires an increased poleward energy flux. Therefore, a mechanism that can account for the increased poleward energy flux is still needed. ...
In fact, the hemisphere-wide  Hadley  cell  (Farrell,  1990),  whose  sinking branch occurs in the Arctic, can warm high-latitude continental interior. However, this theory requires a tropopause height of ~30 km, 2-3 times that of the present-day value.


He proposes another mechanism, calles TEAM. If I got the right (most probably I didn't), this is about an enhanced poleward heat transport via  atmospheric baroclinic eddies (see figure below.

Another interesting paper is Hasegawa 2012 (http://www.clim-past.net/8/1323/2012/cp-8-1323-2012.pdf) called "Drastic shrinking of the Hadley circulation during the mid-Cretaceous Supergreenhouse".  Which concludes that at a certain CO2-level, the Hadley cell actually shrinks:

Quote
The latitudinal shifts in the subtropical high-pressure belt appear to be related to changes in the width of the Hadley circulation, which could be linked to the changes in global temperatures and/or atmospheric CO2 levels during the Cretaceous. These results, in conjunction with observations of modern climate, suggest that (1) the Hadley circulation gradually expands poleward in response to increasing global temperatures and/or atmospheric CO2 levels, and (2) when global temperatures and/or atmospheric CO2 levels exceed a certain threshold, the Hadley circulation drastically shrinks equatorwards.
(p 1333). See also figure below
Title: Re: Stupid Questions :o
Post by: Archimid on November 12, 2016, 12:50:38 PM
Quote
@Archmid; I feel no need to argue with anyone in here but there is a history to this issue on this forum, and what plinius wrote above is correct.

 What plinious wrote was a dismissal of the problem by alluding to the extreme cases (equitable climate) and assuming that's all there is to it. According to his dismissive argument there is nothing in between.  We, as in anyone alive today,  will not see a "stable'  equitable climate in our  lifetime. The transition from a planet like ours to a stable equitable will probably take thousands of years. What we are guaranteed to see is the atmospheric patterns to change from what we had to whatever the new thermodynamics of a warmer planet dictate.

The Atmospheric cells do not have to shift to an equitable climate for us to feel major change. they only needs to be disturbed enough to change climates all over the world.   A few kilometers higher latitude, a little more meandering of the vortex, can create tipping points that change the climate in entire continents.


This is already happening. I don't understand why people keep pretending it is not.




Title: Re: Stupid Questions :o
Post by: Archimid on November 12, 2016, 02:30:49 PM
Therefore, a mechanism that can account for the increased poleward energy flux is still needed. ...
In fact, the hemisphere-wide  Hadley  cell  (Farrell,  1990),  whose  sinking branch occurs in the Arctic, can warm high-latitude continental interior. However, this theory requires a tropopause height of ~30 km, 2-3 times that of the present-day value.


I read that and immediately thought, is the tropopause height changing? If so, how much? A quick google search gave me the attached image. From here: https://www.ipcc.ch/publications_and_data/ar4/wg1/en/fig/figure-9-14-l.png (https://www.ipcc.ch/publications_and_data/ar4/wg1/en/fig/figure-9-14-l.png)

That ends in the year 2000. Since then things have changed significantly. I would love to see the most recent data. My bet is that it follows temperature, so in the hottest year on record I would expect it to change accordingly.


Title: Re: Stupid Questions :o
Post by: Gray-Wolf on November 12, 2016, 02:43:59 PM
Though this is becoming overlong for 'stupid questions' i have to agree with Archimid that we have been seeing climate in the throes of AGW forced change ( via the Arctic) since the late 90's? The 'cold plunges' appeared to become a yearly event somewhere in the northern Hemisphere well before the open water we saw across the Arctic in 07'? From Japan to Greece, from Somalia to China we were seeing temperature/temp extremes as these 'polar outbreaks' became a common feature of northern hemisphere winters.

Last year we saw sub tropical airs plough into the basin at winter Solstice.

These rapid/unmodified airmass exchanges are the planet trying to flip up to a 'warmer setting' as we thicken our GHG blanket.

The energy we see flood the climate system on the first BOE will stoke up this process further and drive even balmier weather events around the areas impacted by rapid air mass exchange.
Title: Re: Stupid Questions :o
Post by: Sleepy on November 12, 2016, 03:30:58 PM
So for someone who is way out of his depth here: Is Persson the go-to guy for these matters? And is the controversy about what caused equable climates on earth resolved now?
1. No, not one single human is the go-to-guy, I think you know that science doesn't work like that.
2. No, but that wasn't the issue, it was about the Hadley cell expanding to the poles now or in a rather near future that caused emotions above (and in the freezing seasons thread). I posted a link to a recent study in the freezing seasons thread as well, about how much the Hadley cell has expanded.
Title: Re: Stupid Questions :o
Post by: Tigertown on November 12, 2016, 08:24:49 PM
Does Hudson Bay usually freeze over before it gets pumped full of ice? There appears to be a pretty good chance it will get imported(from the Bay's standpoint) this year. Is that out of the ordinary?
Title: Re: Stupid Questions :o
Post by: be cause on November 13, 2016, 12:07:31 AM
|Entertaining myself with a brouse of models and their attempts to deal with the uncharted , I note that JMA is forecasting pressure over Greenland to rise beyond 1080 mb . Is this even possible ?
Title: Re: Stupid Questions :o
Post by: Darvince on November 13, 2016, 12:40:24 AM
Yes, it is possible, but extraordinarily unlikely, because the current highest ever measured high pressure was 1086mb in northern Mongolia in the dead of winter. I looked at the run and it shows it peaking at 1090mb which I find absolutely insane, but considering the state of the Arctic and Siberia recently it's also entirely possible.
Title: Re: Stupid Questions :o
Post by: Ice Shieldz on November 13, 2016, 12:44:08 AM
Ha i know fun model madness.  Here is yesterday's ECMWF12Z @180 hours with -60F anomalies! I'm sure some equations in the models are gonna get tweaked or rewritten.   :o  as extreme weather can provide important insights into underlying dynamics and processes.
Title: Re: Stupid Questions :o
Post by: Tigertown on November 13, 2016, 05:54:08 AM
Does Hudson Bay usually freeze over before it gets pumped full of ice? There appears to be a pretty good chance it will get imported(from the Bay's standpoint) this year. Is that out of the ordinary?

Well Tt(hope you don't mind the abbreviation), Whatever happens there in Hudson Bay, it will probably be a while. I just checked and the water temps there are still relatively warm. The better question may be how long will the ice that has wormed its way through the passages to get there will last?
Title: Re: Stupid Questions :o
Post by: Peter Ellis on November 13, 2016, 09:01:07 PM
Does Hudson Bay usually freeze over before it gets pumped full of ice? There appears to be a pretty good chance it will get imported(from the Bay's standpoint) this year. Is that out of the ordinary?

... imported from where? What on Earth are you talking about?  The ice edge is advancing from the North (as it does every single year), but that's not "import", that's just how stuff freezes. The northerly latitudes freeze over before the more southerly latitudes, on account of the shape of the planet.

Are you somehow thinking that ice from the Arctic ocean will make it southward out of the Arctic basin, all the way along the Northwest Passages, then turn east through the Fury and Hecla strait, south again through Foxe Basin and ultimately into Hudson Bay?  When these are already solidly covered with newly-formed first year ice?

Just... what?
Title: Re: Stupid Questions :o
Post by: Shared Humanity on November 13, 2016, 09:10:34 PM
Ahem, Shared-Humanity - So, quite a useless discussion.

It is what I do best.
Title: Re: Stupid Questions :o
Post by: Tigertown on November 14, 2016, 03:16:14 AM
Does Hudson Bay usually freeze over before it gets pumped full of ice? There appears to be a pretty good chance it will get imported(from the Bay's standpoint) this year. Is that out of the ordinary?

... imported from where? What on Earth are you talking about?  The ice edge is advancing from the North (as it does every single year), but that's not "import", that's just how stuff freezes. The northerly latitudes freeze over before the more southerly latitudes, on account of the shape of the planet.

Are you somehow thinking that ice from the Arctic ocean will make it southward out of the Arctic basin, all the way along the Northwest Passages, then turn east through the Fury and Hecla strait, south again through Foxe Basin and ultimately into Hudson Bay?  When these are already solidly covered with newly-formed first year ice?

Just... what?
Did you read the name of this thread? I thought the idea was to be able to ask something without being insulted. I have gone back and watched Polarview now and see that for the most part the ice formed in the northern part. You could have shown a lot more character by just explaining that.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on November 14, 2016, 03:59:31 AM
Does Hudson Bay usually freeze over before it gets pumped full of ice? There appears to be a pretty good chance it will get imported(from the Bay's standpoint) this year. Is that out of the ordinary?

... imported from where? What on Earth are you talking about?  The ice edge is advancing from the North (as it does every single year), but that's not "import", that's just how stuff freezes. The northerly latitudes freeze over before the more southerly latitudes, on account of the shape of the planet.

Are you somehow thinking that ice from the Arctic ocean will make it southward out of the Arctic basin, all the way along the Northwest Passages, then turn east through the Fury and Hecla strait, south again through Foxe Basin and ultimately into Hudson Bay?  When these are already solidly covered with newly-formed first year ice?

Just... what?
Did you read the name of this thread? I thought the idea was to be able to ask something without being insulted. I have gone back and watched Polarview now and see that for the most part the ice formed in the northern part. You could have shown a lot more character by just explaining that.

I thought so as well but apparently this is not the case. Maybe we should create a "Really Stupid Questions" thread and leave this one for the "Know it Alls".
Title: Re: Stupid Questions :o
Post by: magnamentis on November 14, 2016, 04:21:56 AM
Does Hudson Bay usually freeze over before it gets pumped full of ice? There appears to be a pretty good chance it will get imported(from the Bay's standpoint) this year. Is that out of the ordinary?

... imported from where? What on Earth are you talking about?  The ice edge is advancing from the North (as it does every single year), but that's not "import", that's just how stuff freezes. The northerly latitudes freeze over before the more southerly latitudes, on account of the shape of the planet.

Are you somehow thinking that ice from the Arctic ocean will make it southward out of the Arctic basin, all the way along the Northwest Passages, then turn east through the Fury and Hecla strait, south again through Foxe Basin and ultimately into Hudson Bay?  When these are already solidly covered with newly-formed first year ice?

Just... what?
Did you read the name of this thread? I thought the idea was to be able to ask something without being insulted. I have gone back and watched Polarview now and see that for the most part the ice formed in the northern part. You could have shown a lot more character by just explaining that.

hehe... exactly what i thought but then if i had replied referring to the thread title that would have sounded like an offense against you so i refrained to do so, only you could do that LOL

however i share his conclusions and the explanation why, just no need for the condescending tone IMO. enjoy further and yes, perhaps @Shared Humanity is right (JK)

wish you all a nice week though
Title: Re: Stupid Questions :o
Post by: Tigertown on November 14, 2016, 04:37:21 AM
I guess I asked a humdinger of a stupid question. I had been watching Polarview. and it looked just like the ice was coming down through that last little  narrow passage into Foxe Basin and then migrating south. After zooming in, it appears that it may be forming inside the Basin Area instead of passing through. I still have lingering doubts that some cold slush or whatever might be slipping through then freezing back solid. If not it's a pretty good optical illusion.
Title: Re: Stupid Questions :o
Post by: jdallen on November 14, 2016, 09:25:07 AM
I guess I asked a humdinger of a stupid question. I had been watching Polarview. and it looked just like the ice was coming down through that last little  narrow passage into Foxe Basin and then migrating south. After zooming in, it appears that it may be forming inside the Basin Area instead of passing through. I still have lingering doubts that some cold slush or whatever might be slipping through then freezing back solid. If not it's a pretty good optical illusion.
Not enough flow, not fast enough Tigertown.  Just old-fashioned ice forming in place.  The Foxe basin has always been cold, and with air spilling out of the arctic, even the current "superheated" arctic air, is plenty cold enough to start it freezing over.  It's not that deep, and didn't get particularly warm.
Title: Re: Stupid Questions :o
Post by: johnm33 on November 14, 2016, 04:12:47 PM
Tt If you look at the salinity animations in Hy-com you may form the opinion that the water passing through Fury and Hecla is relatively fresh, so easier to freeze.
Title: Re: Stupid Questions :o
Post by: Cate on November 14, 2016, 08:42:28 PM
So is this the highest daily mean temp above 80N ever recorded (by DMI, at any rate) for this date?

http://ocean.dmi.dk/arctic/meant80n.uk.php (http://ocean.dmi.dk/arctic/meant80n.uk.php)
Title: Re: Stupid Questions :o
Post by: Tigertown on November 14, 2016, 08:50:18 PM
Tt If you look at the salinity animations in Hy-com you may form the opinion that the water passing through Fury and Hecla is relatively fresh, so easier to freeze.

That makes sense.
Title: Re: Stupid Questions :o
Post by: TerryM on November 14, 2016, 09:15:30 PM
So is this the highest daily mean temp above 80N ever recorded (by DMI, at any rate) for this date?

http://ocean.dmi.dk/arctic/meant80n.uk.php (http://ocean.dmi.dk/arctic/meant80n.uk.php)


Thumbing back through DMI is seems certain that this is so at least since 1958. I haven't even found a close second for either side of the hump.


We live in exciting times. :'(
Terry
Title: Re: Stupid Questions :o
Post by: magnamentis on November 14, 2016, 10:38:06 PM
So is this the highest daily mean temp above 80N ever recorded (by DMI, at any rate) for this date?

http://ocean.dmi.dk/arctic/meant80n.uk.php (http://ocean.dmi.dk/arctic/meant80n.uk.php)


Thumbing back through DMI is seems certain that this is so at least since 1958. I haven't even found a close second for either side of the hump.


We live in exciting times. :'(
Terry

this and it's getting even warmer the next few days, another 5C up i'd guess
Title: Re: Stupid Questions :o
Post by: jdallen on November 15, 2016, 02:55:04 AM
So is this the highest daily mean temp above 80N ever recorded (by DMI, at any rate) for this date?

http://ocean.dmi.dk/arctic/meant80n.uk.php (http://ocean.dmi.dk/arctic/meant80n.uk.php)


Thumbing back through DMI is seems certain that this is so at least since 1958. I haven't even found a close second for either side of the hump.


We live in exciting times. :'(
Terry

this and it's getting even warmer the next few days, another 5C up i'd guess
Climate Reanalyzer has near zero temps reaching within a couple hundred miles of the pole.  That will definitely keep it warm.
Title: Re: Stupid Questions :o
Post by: Glenn Tamblyn on November 15, 2016, 03:18:35 AM
Those temps on Climate Reanalyser are just bat-shit crazy. Actually suggesting climbing above zero near the pole briefly.

PIOMASS for November is going to look very, very interesting. Could this be the pre-conditioning for 'the big one' next year?

I hope Andrew Slater is able to continue his degree-days freezing graph for this year. Might be quite stunning.
Title: Re: Stupid Questions :o
Post by: bbr2314 on November 15, 2016, 05:06:20 AM
Those temps on Climate Reanalyser are just bat-shit crazy. Actually suggesting climbing above zero near the pole briefly.

PIOMASS for November is going to look very, very interesting. Could this be the pre-conditioning for 'the big one' next year?

I hope Andrew Slater is able to continue his degree-days freezing graph for this year. Might be quite stunning.
Unfortunately Andrew Slater died earlier this year. The graphs have continued updating but I unfortunately think they may stop at the end of the year. RIP, and **** you 2016.
Title: Re: Stupid Questions :o
Post by: oren on November 15, 2016, 05:41:15 AM
The DMI temps are jaw-dropping. Just when I think it's gonna come down when the peripheral ice freezes over, it's coming up instead.
Title: Re: Stupid Questions :o
Post by: Tigertown on November 15, 2016, 06:07:30 AM
Those temps on Climate Reanalyser are just bat-shit crazy. Actually suggesting climbing above zero near the pole briefly.

PIOMASS for November is going to look very, very interesting. Could this be the pre-conditioning for 'the big one' next year?

I hope Andrew Slater is able to continue his degree-days freezing graph for this year. Might be quite stunning.

Tealight to the rescue:
(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2F&hash=35d7d5d7526c9897dfb55501e320295a)
Title: Re: Stupid Questions :o
Post by: seaicesailor on November 15, 2016, 08:54:35 AM
Those temps on Climate Reanalyser are ...

PIOMASS for November is going to look very, very interesting. Could this be the pre-conditioning for 'the big one' next year?
It was said before that Autumn with a very late refreeze such as the one experiencing might precondition for a rebound rather than a crash given the amount of extra heat being released, but that is a weak speculation based on a very little number of examples and, as we are seeing this season other factors in this abnormal climate such as extra humidity, whacked weather and ocean currents play their roles. Who knows if 2017 will look more like 2013 or go below 2012. My feeling is that, given the lack of MYI (and further loses during winter if ice drifts more or less as norm) and the off the chart NH temps in general, a sunny melting season breaking the 2013-2016 streak of cloudy summers will bring a record year.
But a repetition of 2013 might as well happen, why not? It looked so bad in march 2013, so so bad...
Title: Re: Stupid Questions :o
Post by: TerryM on November 15, 2016, 10:07:30 AM
I'm showing -.9 C at the pole according to nullschool at 4:00 AM EST today, 11/15/2016.


Terry
Title: Re: Stupid Questions :o
Post by: Tarkis on November 15, 2016, 03:01:16 PM
Not sure if anyone has already mentioned NASA's recent article on the 2015/16 arctic winter cyclone.

http://www.nasa.gov/feature/goddard/2016/extremely-warm-2015-16-winter-cyclone-weakened-arctic-sea-ice-pack (http://www.nasa.gov/feature/goddard/2016/extremely-warm-2015-16-winter-cyclone-weakened-arctic-sea-ice-pack)

My question is, what are the chances of a repeat of such an event this year?
Title: Re: Stupid Questions :o
Post by: DoomInTheUK on November 16, 2016, 09:40:10 AM
...
My question is, what are the chances of a repeat of such an event this year?

A lot more likely with warmer waters surrounding a smaller extent. The impact could be worse too as the ice is in an even worse state now than last year.

Winter in the Arctic seems to be destabilised at the moment. Let's hope things settle down and we get something like normal temps soon or 2017 will be interesting...in a Chinese kind of way.
Title: Re: Stupid Questions :o
Post by: abbottisgone on November 16, 2016, 10:54:43 AM


Thumbing back through DMI is seems certain that this is so at least since 1958. I haven't even found a close second for either side of the hump.


We live in exciting times. :'(
Terry
I would have said that there are some close examples to what is on the left hand side of the hump, but the right side is certainly unprecedented.

The world is truly watching, you can bet...so, beware of panic I say!

Going thru the years the right side starts to slowly get out of control,... until it just starts to get just a little bit crazier more often:  so I think we are seeing something that has been defined by the past record as indicative of a true signal of things to come.
Title: Re: Stupid Questions :o
Post by: dnem on November 16, 2016, 01:33:50 PM
Been following Wip's combined SIE and SIA graphs but would like to see Antartica data only as well.  What is the best site for up-to-date graphs and data for Antartica?  Having troubling finding them.

Thanks.
Title: Re: Stupid Questions :o
Post by: magnamentis on November 16, 2016, 05:27:51 PM
Been following Wip's combined SIE and SIA graphs but would like to see Antartica data only as well.  What is the best site for up-to-date graphs and data for Antartica?  Having troubling finding them.

Thanks.


often you can use the same sites for both, arctic and antarctic, just switching between the two, what i would like more and more to see is a well established interactive chart for global sea ice, similar to those, which as well are the answer to your question.

https://ads.nipr.ac.jp/vishop/#/extent (https://ads.nipr.ac.jp/vishop/#/extent)

http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/ (http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/)
Title: Re: Stupid Questions :o
Post by: dnem on November 16, 2016, 07:27:35 PM
Too funny. In the hundreds of times I've viewed those charts I never noticed the Antarctica tabs!

Title: Re: Stupid Questions :o
Post by: oren on November 16, 2016, 07:40:50 PM
dnem there's a thread on this forum dealing with sea ice extent around Antarctica.
Title: Re: Stupid Questions :o
Post by: dnem on November 16, 2016, 07:47:09 PM
Thanks Oren.  Information overload  :(
Title: Re: Stupid Questions :o
Post by: dnem on November 17, 2016, 01:10:12 PM
OK, 'nuther one for you all.

I've seen a few references to the "upcoming 65N SSW"?

What is that referring to?

Thanks.
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on November 17, 2016, 01:16:19 PM
Some models are showing a Sudden Stratographic Warming in the next week or so. This can be quite disruptive to N. Hemisphere weather patterns but then can have very little impact? As I understand it the Strat is forced to warm and those changes then propagate down into the troposphere. I'm sure others will give you a fuller explanation that I can't!

But Sudden Stratographic Warming centred over 65N
Title: Re: Stupid Questions :o
Post by: dnem on November 17, 2016, 05:28:08 PM
Thanks G-W.  Just a poor biologist doing my best to hang in here!
Title: Re: Stupid Questions :o
Post by: jdallen on November 17, 2016, 05:53:53 PM
Can we please move the weather discussion out of this thread?
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on November 17, 2016, 06:13:58 PM
Sorry jdallan but ,seeing as it concerned the blasting apart of the Polar Vortex, I thought here would be the place?

I cannot find a dedicated weather thread though or we'd probably not needed to have posted?

As it is the SSW , should it occur, could have a great impact on re-freeze ( esp. so early in the season with a PV that has already split and now faces an SSW) and so could form part of the jigsaw of data need to understand the upcoming winter? Even the QBO glitch , last Feb, could be linked seeing as they are both stratospheric winds descending through the troposphere to the surface?
Title: Re: Stupid Questions :o
Post by: jdallen on November 17, 2016, 06:26:47 PM
Sorry jdallan but ,seeing as it concerned the blasting apart of the Polar Vortex, I thought here would be the place?

I cannot find a dedicated weather thread though or we'd probably not needed to have posted?

It now has a home:

http://forum.arctic-sea-ice.net/index.php/topic,1779.0.html (http://forum.arctic-sea-ice.net/index.php/topic,1779.0.html)
Title: Re: Stupid Questions :o
Post by: Shared Humanity on November 18, 2016, 02:16:10 AM
The question belonged here as it is the Stupid Questions thread although I also don't know much about SSW so it can't be that stupid or maybe....it is and so am I. At any rate, it was not a weather discussion. It was a single question.
Title: Re: Stupid Questions :o
Post by: jdallen on November 18, 2016, 02:40:15 AM
The question belonged here as it is the Stupid Questions thread although I also don't know much about SSW so it can't be that stupid or maybe....it is and so am I. At any rate, it was not a weather discussion. It was a single question.
With respect, it was getting quite a bit past just answering your question, SH ;)
Title: Re: Stupid Questions :o
Post by: oren on November 18, 2016, 08:46:21 AM
With respect, it was getting quite a bit past just answering your question, SH ;)
Three short lines (which I found useful as well), I really can't understand your gripe.
Title: Re: Stupid Questions :o
Post by: ktonine on November 19, 2016, 03:39:09 PM
Is there a repository for the raw data values in the DMI N80 charts?

Just eyeballing the charts it looks like the baseline FFDs from the end of the melt season until now is about 1300, while this year is probably close to 600 -- a deficit of 700 FDDs.  For the entire season the the baseline is a little above 4000 with recent years slightly below that.  A deficit of 700 FDDs for the season would imply a thickness growth reduction of about 0.3m.
Title: Re: Stupid Questions :o
Post by: dnem on November 19, 2016, 10:31:31 PM
No there's not.  I raised the idea of digitizing the charts to extract FDD a few days ago and someone actually did it using Python.  It's on one of the threads.  I'll try and find it.
Title: Re: Stupid Questions :o
Post by: dnem on November 19, 2016, 10:39:31 PM
Check out
Re: The 2016/2017 freezing season
« Reply #694 on: November 14, 2016, 11:27:46 PM
Title: Re: Stupid Questions :o
Post by: ktonine on November 20, 2016, 12:47:00 AM
Check out
Re: The 2016/2017 freezing season
« Reply #694 on: November 14, 2016, 11:27:46 PM

dnem- thanks. 

I had seen Tealight's post, but the numbers he has are for the entire year, not the freezing season.  His annual numbers also disagree quite a bit with the numbers Chris Reynold's used (http://dosbat.blogspot.com/2015/01/the-simplest-model-of-sea-ice-growth.html) on his dosbat blog -- where the annual total was under 4000 for recent years.

Unfortunately I'm not a graphics wizard otherwise I'd digitize them myself.  I'd have to pixel count and that's just too boring :)


Title: Re: Stupid Questions :o
Post by: Jim Hunt on November 20, 2016, 01:52:34 AM
No there's not.

Actually there is. For the 2016 numbers see:

ftp.dmi.dk/plus80N_temperatureindex/ (ftp://ftp.dmi.dk/plus80N_temperatureindex/)

For previous years see the attachment, which is actually a ZIP archive.
Title: Re: Stupid Questions :o
Post by: ktonine on November 20, 2016, 02:06:18 AM
No there's not.

Actually there is. For the 2016 numbers see:

ftp.dmi.dk/plus80N_temperatureindex/ (ftp://ftp.dmi.dk/plus80N_temperatureindex/)

For previous years see the attachment, which is actually a ZIP archive.

Thanks, Jim :)
Title: Re: Stupid Questions :o
Post by: dnem on November 20, 2016, 01:40:51 PM
Thanks Jim.  The question was asked a few times a week or two back and no one pointed to that ftp site. Thanks again and sorry for misleading.
Title: Re: Stupid Questions :o
Post by: Sarat on November 23, 2016, 10:20:32 PM
Is it just me or the climate "skeptics" of WUWT are staying very quiet on the news of current state of the arctic?

Despite the terrible state of the global sea ice, perhaps the only silver lining is seeing them unable to cherry pick their way out of this one.

Title: Re: Stupid Questions :o
Post by: Gray-Wolf on November 23, 2016, 10:41:40 PM
Their last attempt was at a 'Arctic ice stages record recovery!!!' back in Sept but surely folk know that when ice drops to near record lows it will 'appear' to put on ice really fast as the Central Arctic rapidly cools?

As it is they've now lost their favourite go to " oh look! a Squirrel" as I'm sure the current MSM coverage of the 'extreme' low ice around both North/South Poles means we all know how dire things currently are?
Title: Re: Stupid Questions :o
Post by: Sarat on November 23, 2016, 11:00:23 PM
Thanks Grey Wolf,

Yes, and that post is now also shown to be glaringly wrong, too bad there is very little retrospection there. Most of their "cherries" tend to rot over time, some faster than others.

Title: Re: Stupid Questions :o
Post by: Michael J on November 23, 2016, 11:20:55 PM
Their last attempt was at a 'Arctic ice stages record recovery!!!' back in Sept but surely folk know that when ice drops to near record lows it will 'appear' to put on ice really fast as the Central Arctic rapidly cools?

As it is they've now lost their favourite go to " oh look! a Squirrel" as I'm sure the current MSM coverage of the 'extreme' low ice around both North/South Poles means we all know how dire things currently are?

If the weather cools and the ice rapidly grows they will get noisy again. I have noticed a few saying that the arctic was ice free some distant millennia in the past so why the worry
Title: Re: Stupid Questions :o
Post by: jdallen on November 23, 2016, 11:26:33 PM
Their last attempt was at a 'Arctic ice stages record recovery!!!' back in Sept but surely folk know that when ice drops to near record lows it will 'appear' to put on ice really fast as the Central Arctic rapidly cools?

As it is they've now lost their favourite go to " oh look! a Squirrel" as I'm sure the current MSM coverage of the 'extreme' low ice around both North/South Poles means we all know how dire things currently are?

If the weather cools and the ice rapidly grows they will get noisy again. I have noticed a few saying that the arctic was ice free some distant millennia in the past so why the worry
You know, it occurs to me, we may have an answer to that.  <puts on research hat> off to dig up a bit of paleoclimatology for S. Asia, SE Asia and sub-saharan Africa...
Title: Re: Stupid Questions :o
Post by: Tony Mcleod on November 23, 2016, 11:46:48 PM
Hi all, been lurking here daily for a while and what a fascinating blog. I live in a pretty warm part of the world (just north of Brisbane, 8:40am and pushing past 28C) so my experience and knowledge of ice is pretty limited. So it's more likely I post in this thread than any other...

I do visit WUWT - just to see what misapprehensions they are under and I will chip in and stir them up a bit if I just can't bare to allow the nonsense to go unchallenged. I've posted the much talked about graph on a couple of different threads there and the only substantial replies have been about whether the equipment is faulty! Some there are really drowning in the Kool-aid.

It is interesting to see they are wanting to talk about anything except the climate at the moment.
Tony ::) ::)
Title: Re: Stupid Questions :o
Post by: oren on November 25, 2016, 07:54:23 AM
Welcome Tony! The first post is the hardest.
Title: Re: Stupid Questions :o
Post by: Tony Mcleod on November 25, 2016, 08:44:37 AM
More an observation rather than a question but it appears the infamous graph is not on the Arctic Sea Ice Graphs page, whereas this is Cryosat today graph is, even though it broke six months ago.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on November 25, 2016, 10:10:30 AM
More an observation rather than a question but it appears the infamous graph is not on the Arctic Sea Ice Graphs page, whereas this is Cryosat today graph is, even though it broke six months ago.

If you're referring to the global ice image showing the st dev from normal, i guess almost nobody thought this metric could behave like it currently does. The graphs page has been reserved to graphs that are regularly updated and this one isn't. Neven has occasionally changed the graphs page. CT has a long data series so I guess thats the reason. But possibly this global metric now gets followed more regularly.
Title: Re: Stupid Questions :o
Post by: Gray-Wolf on November 25, 2016, 11:15:36 AM
I have also come across Deniers refusing the data but then holding up C.T. images to 'prove' that something is up with the data??? Seeing as both NSIDC and JAXA run daily values for ice extent/area you should give them the option of making the graph themselves. Also 'Sunshine hours' was set up during the 'Squirrel' years so the Deniers already had their own 'go to' global sea ice levels graph( even if it is lagging well behind in time .... for some reason they appear reluctant to update?) yet also appear to have 'forgotten' the hold such a resource?

Another Stupid Question: Seeing as the deniosphere appears to be reflecting , and not posting, on global issues at the moment what scale of Arctic/Antarctic event will it take to see them melt away as fast as the ice?
Title: Re: Stupid Questions :o
Post by: oren on November 25, 2016, 11:28:34 AM
More an observation rather than a question but it appears the infamous graph is not on the Arctic Sea Ice Graphs page, whereas this is Cryosat today graph is, even though it broke six months ago.

If you're referring to the global ice image showing the st dev from normal, i guess almost nobody thought this metric could behave like it currently does. The graphs page has been reserved to graphs that are regularly updated and this one isn't. Neven has occasionally changed the graphs page. CT has a long data series so I guess thats the reason. But possibly this global metric now gets followed more regularly.
Actually the amazing Wipneus updates this graph regularly now on his
ArctischePinguin site , I guess Neven should replace the current CT chart with Wipneus' version.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on November 25, 2016, 12:45:49 PM

<clip>
Another Stupid Question: Seeing as the deniosphere appears to be reflecting , and not posting, on global issues at the moment what scale of Arctic/Antarctic event will it take to see them melt away as fast as the ice?
This has been discussed among friends on occasion. We're pretty much on common ground that the level of stupid among them is such that losing one large city to the sea level rise in the 'developed world' might just be enough. Of course this happens during some freak storm, making it unfeasible to build it up agaim, so it could be we're too optimistic about this.
Title: Re: Stupid Questions :o
Post by: Tony Mcleod on November 25, 2016, 01:05:12 PM
More an observation rather than a question but it appears the infamous graph is not on the Arctic Sea Ice Graphs page, whereas this is Cryosat today graph is, even though it broke six months ago.

If you're referring to the global ice image showing the st dev from normal, i guess almost nobody thought this metric could behave like it currently does. The graphs page has been reserved to graphs that are regularly updated and this one isn't. Neven has occasionally changed the graphs page. CT has a long data series so I guess thats the reason. But possibly this global metric now gets followed more regularly.

Seems likely it will from now on.
Title: Re: Stupid Questions :o
Post by: binntho on November 25, 2016, 02:17:44 PM
The deniospehere probably won't depopulate significantly for a few decades, or when the evidence is overwhelming and (perhaps most important) there is general acknowledgment that it's too late to do anything about it.
Title: Re: Stupid Questions :o
Post by: Sarat on November 25, 2016, 04:56:41 PM
Even that is wishful thinking, the key word is believe* not understand, people are capable of believing many things and no amout of evidence can change that... new earth creationists, flat earthers, people refusing medicine in favor of homeopathy and getting worse. They all are confronted with undeniable factual proof but they dismiss it if it contradicts their religion, sense of community, political identity  etc. People who believe* in global warming instead of understanding it are not much better, but their sentiments are at least not as damaging to the need to influence change.
Title: Re: Stupid Questions :o
Post by: TerryM on November 25, 2016, 09:06:09 PM
Sarat
I believe you've spotted the problem. Just as centuries of medical advances haven't wiped out belief in priests, witch doctors and homeopaths, so loosing the city next door won't put climate denialists out of business. We do now tend to spend more on medical centers than on cathedrals, but new spires continue to adorn some pretty pricey real estate, and southern governors still pray for rain.
Terry
Title: Re: Stupid Questions :o
Post by: Cate on November 25, 2016, 09:28:39 PM

<clip>
Another Stupid Question: Seeing as the deniosphere appears to be reflecting , and not posting, on global issues at the moment what scale of Arctic/Antarctic event will it take to see them melt away as fast as the ice?
This has been discussed among friends on occasion. We're pretty much on common ground that the level of stupid among them is such that losing one large city to the sea level rise in the 'developed world' might just be enough. Of course this happens during some freak storm, making it unfeasible to build it up agaim, so it could be we're too optimistic about this.

Didn't that already happen, losing one large city (or a goodly part of it) in the developed world...in the US, in fact..during some freak storm...? New Orleans?....but of course, that didn't count. New Orleans is....you know.

 :(
Title: Re: Stupid Questions :o
Post by: oren on November 25, 2016, 10:00:46 PM
Didn't that already happen, losing one large city (or a goodly part of it) in the developed world...in the US, in fact..during some freak storm...? New Orleans?....but of course, that didn't count. New Orleans is....you know.

 :(
So right.
Title: Re: Stupid Questions :o
Post by: Michael J on November 25, 2016, 11:53:27 PM
The major problem is that the Climate Change denial is part of a particular political movement and well funded by the energy industry. In the Australian experience it had originally almost universal acceptance. Then money went from the mining industry into our right wing party and then acceptance went down to under 50%. Now acceptance is slowly but steadily growing such that the right-wing party (LNP) is not able to deny it as policy (even though individuals in the party do) .  However, the LNP does everything it can to delay actually doing anything effective.
I think eventually acceptance of Climate Change will be so high that it will be political suicide for a party not to do something.

I think after the next city to have a disaster. There wont be a lot of minds changed but the roar from the people who accept climate change may actually move the politicians to do something.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on November 26, 2016, 02:34:38 PM
Didn't that already happen, losing one large city (or a goodly part of it) in the developed world...in the US, in fact..during some freak storm...? New Orleans?....but of course, that didn't count. New Orleans is....you know.

 :(

No, cities built under mean sea level do no count. As doesn't Venice since it's always flooding. Neither counted are cities in the third world. It's weird but the deniers want to drown these, at least that's my interpretation. Not very humane.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on November 26, 2016, 10:08:01 PM
By 2070, we will be abandoning southern Florida. People will be angry and there will be nothing we can do about it.
Title: Re: Stupid Questions :o
Post by: Iceismylife on November 28, 2016, 06:21:51 PM
By 2070, we will be abandoning southern Florida. People will be angry and there will be nothing we can do about it.
There are three possible cases:

1.  Global climate change is overestimated and over blown.  (Big river in Egypt any one?)

2.  Global climate change is happen as predicted.

3.  Global climate change is under estimated.

Looking at the history. People have been modeling CO2 and its effects.  Accurate climate models have lagged CO2 predictive models.  If something like Albedo was the main driver of climate change not CO2 then we are in for a rude awakening. 

My money is on case number three.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on November 28, 2016, 06:44:01 PM
<clip>

2.  Global climate change is happen as predicted.

3.  Global climate change is under estimated.

Looking at the history. People have been modeling CO2 and its effects.  Accurate climate models have lagged CO2 predictive models.  If something like Albedo was the main driver of climate change not CO2 then we are in for a rude awakening. 

My money is on case number three.

it so happens that Antarctic ice is at a local minimum during the early southern summer 2016-7. Once arctic goes ice free the warmed up airs of northern hemisphere may cool only over Greenland accelerating the melt there. Large ice/snow fields generate their own weather by the albedo mechanism. This may lead to rainstorms constantly circling Greenland and as ice and water don't mix for long at least, the melt there should accelerate.

Antarctica glaciers and ice sheets are better protected from this sort of attack but as many of them are grounded in the ocean, tqhey're vulnerable to the heat of the oceans.
Title: Re: Stupid Questions :o
Post by: JuniorMint on December 11, 2016, 06:50:02 AM
Hello,

First post, longish time lurker...

I have a potentially really dumb question. I've been following all the major threads here for a while now. I was wondering why there was such a difference in the reported SIEs....For example....

IJIS Dec 9 = 10,365,460 km2
NSIDC Dec 9 = 10,624,000 km2

I am really only really beginning to understand all the various resources you guys use and so I am not familiar with how they might measure SIE differently. Maybe someone could also enlighten me on the pros/cons of the different measuring methods. I have very little in the way of background in this subject matter and its been a very steep learning curve just trying to figure out what y'all are saying ;) (which is why I lurked so long). You'll have to explain it as simply as possible...although I think I have some basics down.

On the NSIDC website under FAQ they say that they may differ slightly from others because "extent measurements differ because of variation in the formulas (algorithms) used for the calculation, the sensor used, the threshold method to determine whether a region is “ice-covered,” and processing methods." - Which I totally get and understand. So my questions are:

* Why is the difference so big say between IJIS/NSIDC right now?

* Could I possibly have some enlightenment on the pros/cons of these different sources?

* I wouldn't mind your opinions on which ones you prefer (and why)

Sorry if this has been asked before, I can't seem to find much information that would enlighten me on these various methods of measuring SIE.

Please be kind. :P

JuniorMint
Title: Re: Stupid Questions :o
Post by: Neven on December 11, 2016, 11:21:48 AM
That's a very good stupid question, JuniorMint.  ;)

The difference that is easiest to understand, is that one dataset may look at a larger region than the other. For instance, some measure lake ice, other's don't. Or perhaps sea ice as south as Newfoundland Bay. I don't know these differences in detail, but that could also be a possible explanation, besides different interpretations/algorithms of what the various microwave bands present, and differences in land mask.

Another difference between JAXA and NSIDC is that the former uses data from the ASMR2 sensor (higher resolution) and the latter uses SSMIS (lower resolution).
Title: Re: Stupid Questions :o
Post by: Pmt111500 on December 11, 2016, 11:53:11 AM
(Adds a more stupid answer) It's not like there aren't differences between datasets. The situation is pretty much the same as when you asked several people in the old days what's the exact time, you'd normally get hours right, minutes less securely, and seconds were pretty much random. Of course nowadays we have internet time to rely on so there's no need to discuss whose clock is the most accurate. On sea ice we have 3-5 various satellites measuring the ice with different accuracies so we get various results. Then there are various ways to include and exclude data (refers back to Nevens answer
Title: Re: Stupid Questions :o
Post by: Jim Hunt on December 11, 2016, 12:43:11 PM
I was wondering why there was such a difference in the reported SIEs

Apart from different satellite sensors there are also a variety of different algorithms for extracting sea ice concentration numbers from the raw data. For an overview see:

https://climatedataguide.ucar.edu/climate-data/sea-ice-concentration-data-overview-comparison-table-and-graphs

Quote
The most widely used sea ice data sets for climate research are derived from passive microwave instruments, including SMMR, SSMI, SSMIS, AMSR-E and AMSR-2, flying on various satellite platforms. The algorithms applied to the microwave brightness temperatures use different combinations of channels, making different corrections for weather, satellite drift, and other factors. Users of sea ice data should be aware of the different algorithms and their attributes, the different spatial footprints of the satellite instruments and channels, and the methods for combining different source data into long-term data sets.
Title: Re: Stupid Questions :o
Post by: Tealight on December 11, 2016, 01:13:23 PM
I highly recommed watching this webinar from the Sea Ice Prediction Network. It explains all sensor differences better than we could do on the forum.

https://youtu.be/_81Qk7fcYDQ
Title: Re: Stupid Questions :o
Post by: dnem on December 11, 2016, 02:31:55 PM
Not sure if this is right in this case, but some of the measures present a daily measure and others a five day trailing average.  IJIS daily and NSIDC five day?
Title: Re: Stupid Questions :o
Post by: crandles on December 11, 2016, 03:47:09 PM
Not sure if this is right in this case, but some of the measures present a daily measure and others a five day trailing average.  IJIS daily and NSIDC five day?

Yes 10.624 is on chartic graph which shows 5 day average.
ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/NH_seaice_extent_nrt_v2.csv
shows daily numbers: 10.809 for Dec 9th which is a bigger difference.
Title: Re: Stupid Questions :o
Post by: Wipneus on December 11, 2016, 06:12:54 PM
Quote
I have a potentially really dumb question

Not dumb at all. I am trying for years to get some quantitatively  answers to these questions.

Some reactions point to the different algorithms used. This is true, but the fact is that the NT algorithm used by NSIDC almost always calculates a lower sea ice concentration than the BT algorithm used by Jaxa. That explains a lower area (NSIDC area about 300k below Jaxa), but not why the extent is higher.

Now it is important to realize that extent is inherently and by definition depending on the resolution of the sensors and the grid in which sea ice concentration is represented. Extent, by definition calculates the open water in grid cells with 15% ice or more as 100%. High enough resolution to be able to resolve the open water would not and give the same amount of ice as area.
Higher resolution also reduces "false coastal ice" from land spillover. If not effectively filtered this will increase extent of the low resolution product.

Quote
* Why is the difference so big say between IJIS/NSIDC right now?
Resolution and land spillover, that will have to be my answer to your first question.

Best advice is to compare likes with likes. So Jaxa with Jaxa and NSIDC with NSIDC.

Quote
* Could I possibly have some enlightenment on the pros/cons of these different sources?

Jaxa uses the better sensor (better resolution and accuracy), the algorithm is probably better (but opinions differ), but that is only true for AMSR2 data available since August 2012. Earlier dates are using different satellites, the influence of that is unknown to me.

NSIDC on the other hand has taken care to produce extent data that can be reliably compared over the longest time span available (since end 1978).

Quote
* I wouldn't mind your opinions on which ones you prefer (and why)

I depends, reason given above. Jaxa will produce the better day-to-day numbers, but in comparing them with pre-AMSR2 years I hold  a healthy skepticism.
For climatology relevant work there is only NSIDC.
 
NT=Nasa Team algorithm
BT=Bootstrap algorithm
Title: Re: Stupid Questions :o
Post by: ktonine on December 11, 2016, 06:26:26 PM
NSIDC on the other hand has taken care to produce extent data that can be reliably compared over the longest time span available (since end 1978).

This is an important point.  It's why we don't want to use MASIE for year-to-year comparisons.  In science, for long-term comparisons, consistency of method is as important -- if not more important -- than the accuracy of the method. 

We can scan the earth from space with much better resolution today than we could 40 years ago, but the results will then be *inconsistent* with results generated 40 years ago.  Comparisons of the two will be inherently misleading. 
Title: Re: Stupid Questions :o
Post by: JuniorMint on December 11, 2016, 07:03:26 PM
Wow! Thank you for all your great answers. Its very helpful and I think I understand a little bit more then I did yesterday :) I don't have any follow-up questions but if I think of some I will be sure to ask.
Title: Re: Stupid Questions :o
Post by: Feeltheburn on December 12, 2016, 04:20:08 AM
Didn't that already happen, losing one large city (or a goodly part of it) in the developed world...in the US, in fact..during some freak storm...? New Orleans?....but of course, that didn't count. New Orleans is....you know.

 :(

No, cities built under mean sea level do no count. As doesn't Venice since it's always flooding. Neither counted are cities in the third world. It's weird but the deniers want to drown these, at least that's my interpretation. Not very humane.

Building a city below sea level has always been a gamble. Consider the flood history of Holland, which has nothing to do with man-made climate change.

https://en.wikipedia.org/wiki/Floods_in_the_Netherlands
Title: Re: Stupid Questions :o
Post by: Darvince on December 12, 2016, 05:41:38 AM
And so is burning massive amounts of carbon stored in rocks and as sludge underground which has not been a part of the biosphere for many millions of years. And another, even bigger gamble, is betting on a stable climate when this carbon is released through burning and combustion, and betting that ice currently stored above sea level will not melt when this warming agent is added to the atmosphere. And an even bigger gamble yet is conducting government actions acting as if this is not happening, making your society incredibly vulnerable to changes in the climate which your society also initiates by burning carbon that was stored underground through processes which took millions of years.

And perhaps the biggest gamble of all is acknowledging that all of this may come to pass, yet seeing it as a good thing for a society which thrives off of unchanging earth systems.
Title: Re: Stupid Questions :o
Post by: jdallen on December 12, 2016, 08:24:36 AM
Succinct summary, Darvince.
Title: Re: Stupid Questions :o
Post by: Jim Hunt on December 12, 2016, 09:27:36 AM
This is an important point.  It's why we don't want to use MASIE for year-to-year comparisons.  In science, for long-term comparisons, consistency of method is as important -- if not more important -- than the accuracy of the method.

NASA's Walt Meier on the pros and cons of MASIE:

http://GreatWhiteCon.info/2016/02/dmi-masie-and-the-sea-ice-index-an-interview-with-walt-meier/ (http://GreatWhiteCon.info/2016/02/dmi-masie-and-the-sea-ice-index-an-interview-with-walt-meier/)
Title: Re: Stupid Questions :o
Post by: shmengie on December 16, 2016, 09:54:22 PM
I feel like an idiot or horrifyingly mis-informed.

Every paper and website I can find about methane (CH₄) attribute rapid increases to something other than fossil fuels.

I don't have a full understanding of fracking, but...  The idea is basically to unlock and extract methane and oil from shale deposits roughly a mile below ground level.

Oklahoma’s earthquake epidemic has been linked to fracking.  240 quakes in 2014 alone.  Fracturing releases methane from shale deposits and earth quakes can create fissures, what study links these two together.  None that I can find.

How true is it that methane leaks from water wells near fracking sites?  I've seen reports citing it, but I don't know if they simply anti-fracking propaganda or real.  If they're real, why would water wells be the *ONLY* place excess methane leaks out of the ground???

This paper (http://www.eeb.cornell.edu/howarth/publications/f_EECT-61539-perspectives-on-air-emissions-of-methane-and-climatic-warmin_100815_27470.pdf) suggests that Fossil fuel industry grossly under reports methane spill, from dilling sites.  I doubt they bother with incidentals like well and fissure leaks either.

Frack production of methane aligns well, with increased atmospheric methane content in recent years.  So why does every paper look for other sources?

I believe Factory farming may be a serious contributor, but that seems to be another set of industrial secrets, not easily cracked.

Perhaps a small plane carbon tax could include methane monitoring equipment, then we could have substantial information to base more comprehensive understanding.  Wouldn't Trump just love that....  OMG.
Title: Re: Stupid Questions :o
Post by: Tigertown on December 16, 2016, 10:36:17 PM
Most of the problems in Oklahoma are not from fracking but from wastewater disposal. The oil has water mixed in when it comes out and when separated, the water is contaminated and they drill down below the original well to have a place to dispose of it. It is injected into rock that has not been touched before, whereas fracking is done where oil and gas has been extracted once already.
 https://earthquake.usgs.gov/research/induced/myths.php

Edit: Yes methane leakage is believed to be astronomically higher than reported.
Title: Re: Stupid Questions :o
Post by: shmengie on December 16, 2016, 11:25:26 PM
Most of the problems in Oklahoma are not from fracking but from wastewater disposal. The oil has water mixed in when it comes out and when separated, the water is contaminated and they drill down below the original well to have a place to dispose of it. It is injected into rock that has not been touched before, whereas fracking is done where oil and gas has been extracted once already.

Okay, so it's not directly caused by fracking...  Tho I doubt that's *entirely* true... It's not a "myth", if it is indirect consequence of fracking.  But the point I was making is that methane is fracked loose from shale.  Now the Earth quakes more than before, which likely create fissures thru which non contained methane freely seeps into the atmosphere. 

But who bother to make a case to studying it???  The Oil industry probably doesn't like the fact and any publication of what appears an obvious consequence will not encourage fracking.  They already work diligently (as I understand) to suppress fresh water contamination...  Nobody talks about this stuff, so they're not likely to bring it up...

But every study I can find points to agriculture or sea or other natural sources.  Its everywhere, but the most obvious culprit, why???????
Title: Re: Stupid Questions :o
Post by: Tigertown on December 16, 2016, 11:40:16 PM
What I was trying to get across for one thing, is that there is a lot of conventional  drilling going on that doesn't involve fracking, which I am not saying is harmless.

It is also well known about methane leaks from drilling sites and pipelines.

https://www.scientificamerican.com/article/methane-leaks-from-oil-and-gas-wells-now-top-polluters/ (https://www.scientificamerican.com/article/methane-leaks-from-oil-and-gas-wells-now-top-polluters/)

www.nytimes.com/2016/05/13/us/obama-methane-epa.html?_r=0 (http://www.nytimes.com/2016/05/13/us/obama-methane-epa.html?_r=0)

Edit: I do see where you are coming from, though.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on December 17, 2016, 03:02:51 PM
I am aware that methane CH4 is a far more powerful greenhouse gas than CO2. What about H2O? We know the moisture load is increasing in the atmosphere and will continue to do so as it warms. How does it compare as a greenhouse gas? Given its physical state (liquid versus gas), how does it behave (perform) as a greenhouse gas in the atmosphere and how is this different than CO2? Does it have different (more complicated) impacts than CO2? Is it a stronger greenhouse gas or weaker?

Well....OK....that's 5 questions.  8)


(Note: Neven...I would have posted this on "Stupid Questions" in the Science section but could not find it. Maybe we should create and pin a stupid questions topic for each of the major sections. It'll give me my own personal sandbox to play in.)  :o
Title: Re: Stupid Questions :o
Post by: crandles on December 17, 2016, 03:23:27 PM
I am aware that methane CH4 is a far more powerful greenhouse gas than CO2. What about H2O? We know the moisture load is increasing in the atmosphere and will continue to do so as it warms. How does it compare as a greenhouse gas? Given its physical state (liquid versus gas), how does it behave (perform) as a greenhouse gas in the atmosphere and how is this different than CO2? Does it have different (more complicated) impacts than CO2? Is it a stronger greenhouse gas or weaker?

Well....OK....that's 5 questions.  8)


(Note: Neven...I would have posted this on "Stupid Questions" in the Science section but could not find it. Maybe we should create and pin a stupid questions topic for each of the major sections. It'll give me my own personal sandbox to play in.)  :o

Water as a liquid in atmosphere is clouds which are complicated.

Water as a gas is a stronger GHG than CO2. However the level of water vapour in atmosphere adjusts quickly to temperature - average residency time is just 11 days. Therefore emitting steam is not considered a climate forcing. Increase other GHG and this is a forcing which increases temperature which increases water vapour level which further increases temperature. This is well known and in built into the effects expected from that 'increase other GHG' forcing.
Title: Re: Stupid Questions :o
Post by: Tealight on December 18, 2016, 12:50:19 AM
I am aware that methane CH4 is a far more powerful greenhouse gas than CO2. What about H2O? We know the moisture load is increasing in the atmosphere and will continue to do so as it warms. How does it compare as a greenhouse gas? Given its physical state (liquid versus gas), how does it behave (perform) as a greenhouse gas in the atmosphere and how is this different than CO2? Does it have different (more complicated) impacts than CO2? Is it a stronger greenhouse gas or weaker?

Water vapour is without question the strongest greenhouse gas on earth. Its absorbtion sprectrum is much wider than CO2 and it is more abdundant then any other greenhouse gas. Calculating its global warming potential is difficult because unlike CO2 its abdundance varies significantly across the globe. Adding a bit of water vapour to the tropics won't increase warming because there already is a lot of water vapour reflecting its specific wavelengths. In dry climates like the Arctic this is not the case and additional water vapour will have a very high warming potential. I don't feel the low average residency time of water vapour deceases its warming potential because it gets constantly replenished.

(https://upload.wikimedia.org/wikipedia/commons/5/57/CO2_H2O_absorption_atmospheric_gases_unique_pattern_energy_wavelengths_of_energy_transparent_to_others.png)

Greenhouse warming by gas
https://en.wikipedia.org/wiki/Greenhouse_gas#Impacts_on_the_overall_greenhouse_effect
Title: Re: Stupid Questions :o
Post by: wili on December 18, 2016, 03:01:49 AM
Thanks tealight. This, to me, is the central reason that we are likely to see the Arctic move rather rapidly into a condition where ice barely recovers through the winter. It seems to me that this GHG effect of water vapor in the Arctic has not been given the play and publicity it needs.
Title: Re: Stupid Questions :o
Post by: Hefaistos on December 18, 2016, 10:37:07 AM
There is a chemical link between methane and water vapor:

When methane oxidises it produces not only CO2, but water as well:
CH4 + 2O2 → CO2 + 2H2O

Increasing levels of methane is a major source of water vapor in the stratosphere, which is otherwise very dry.
Levels of both water vapor and methane are increasing, see links:

https://www.esrl.noaa.gov/gmd/ozwv/wvap/ (https://www.esrl.noaa.gov/gmd/ozwv/wvap/)
https://public.wmo.int/en/resources/bulletin/observing-water-vapour (https://public.wmo.int/en/resources/bulletin/observing-water-vapour)
https://en.wikipedia.org/wiki/Water_vapor#In_Earth.27s_atmosphere (https://en.wikipedia.org/wiki/Water_vapor#In_Earth.27s_atmosphere)
Title: Re: Stupid Questions :o
Post by: Hefaistos on December 18, 2016, 10:44:03 AM
"The amount of methane oxidized in the stratosphere increased considerably during 1980–2010, but this source can account for at most 28 ± 4%, 14 ± 4%, and 25 ± 5% of the net stratospheric water vapor increases during 1980–2000, 1990–2000, and 1980–2010, respectively."

https://www.researchgate.net/profile/Sean_Davis2/publication/216809524_Stratospheric_water_vapor_trends_over_Boulder_Colorado_Analysis_of_the_30_year_Boulder_record/links/0d6f16832d1df8c7626bbdc4.pdf (https://www.researchgate.net/profile/Sean_Davis2/publication/216809524_Stratospheric_water_vapor_trends_over_Boulder_Colorado_Analysis_of_the_30_year_Boulder_record/links/0d6f16832d1df8c7626bbdc4.pdf)
Title: Re: Stupid Questions : Hydrokinetic energy
Post by: logicmanPatrick on December 18, 2016, 04:28:04 PM
Does anyone know of a paper or discussion on the heat energy of falling water in the cryosphere?

The power of falling water is given as P = ηpQgh where

η = efficiency factor, percentage efficiency expressed as a decimal
P = power in Watts
p = density of the water
Q = flow rate in cubic meters/second
g = gravitational acceleration
h = head in meters (difference between inlet and outlet levels)

For ice, as for turbines, an efficiency factor is needed. When water flows over ice or falls through it, heat is generated at each disturbance in the flow.  This heat is less than would be generated by water falling unimpeded.

My point is that water flowing over ice or through it into the sea must be heated to at least some degree on its downward journey.  This will likely promote melting of glacier ice and / or promote local sea temperature rise.

So, has this been discussed anywhere?
Title: Re: Stupid Questions :o
Post by: longwalks1 on December 18, 2016, 05:23:01 PM
I can't lay my hands or eyes on the sources, but I am pretty sure that the splitting of methane in the atmosphere is rate limited by the hydroxyl radical. 

Found some    http://www.annualreviews.org/doi/abs/10.1146/annurev.pc.39.100188.002055?journalCode=physchem (http://www.annualreviews.org/doi/abs/10.1146/annurev.pc.39.100188.002055?journalCode=physchem)
Quote
Ann. Rev. Phys. Chern. 1988. 39: 367-94
KINETICS OF RADICAL REACTIONS IN THE ATMOSPHERIC OXIDATION OF CH4   1

Quote
A R. Ravishankara Aeronomy Laboratory, National Oceanic and Atmospheric Administration,Boulder,Colorado 80303

Shame it is not opensource   DOI: 10.1146/annurev.pc.39.100188.002055  Especially shameful as footnote one states
1 The US Government has the right to retain a nonexclusive, royalty-free license ...

Copy and paste not working on the pdf  Highlights  - 30% of the carbon monoxide is from CH4 oxidation.    The photolysis of methane is unimportant below the mesoshpere. 

Anyone finding a newer and or better distillation of methane atmospheric oxidation and posting it would be a stellar individual..  Possibly post into the Methane thread with the excitable name.  peace out
Title: Re: Stupid Questions : Hydrokinetic energy
Post by: SteveMDFP on December 18, 2016, 05:35:02 PM
Does anyone know of a paper or discussion on the heat energy of falling water in the cryosphere?

The power of falling water is given as P = ηpQgh where

η = efficiency factor, percentage efficiency expressed as a decimal
P = power in Watts
p = density of the water
Q = flow rate in cubic meters/second
g = gravitational acceleration
h = head in meters (difference between inlet and outlet levels)

For ice, as for turbines, an efficiency factor is needed. When water flows over ice or falls through it, heat is generated at each disturbance in the flow.  This heat is less than would be generated by water falling unimpeded.

My point is that water flowing over ice or through it into the sea must be heated to at least some degree on its downward journey.  This will likely promote melting of glacier ice and / or promote local sea temperature rise.

So, has this been discussed anywhere?

Of course, that efficiency factor is only relevant if you're talking about power output of a hydroelectric dam.  When water in nature falls, all the energy ends up as heat, whether it falls straight down, on a slope, in steps, whatever.  Though it seems like there should be a lot of warming of water as it drops, the actual warming from falling from rather great heights is fairly miniscule for the tens to a couple of hundred meters we're dealing with.  It's been a long time since I studied physics to run the calculation, but I think even if you took ice at -20C from the top of Greenland, kept all the potential energy in it as heat as it dropped to sea level, you'd maybe get enough warmth to bring it maybe to the melting point after 3km, but not actually melt it.
Title: Re: Stupid Questions :o
Post by: Peter Ellis on December 18, 2016, 05:47:10 PM
Gravitational potential energy = mgh ~= 10  kilojoules per kilogram per kilometer of height.
Specific heat capacity of ice = 2.1 kilojoules per kilogram per degree Kelvin.

Ergo dropping a chunk of ice one km and converting all that energy to heating the ice would raise its temperature by ~5 degrees.

Similarly, water falling downwards by one km and converting all that energy to heating the water would raise its temperature by about 2.5 degrees.  James Joule himself actually considered trying this, but found it impractical due to the amount of spray at the bottom of the waterfall - i.e. not all the energy actually goes into heating the water!

Specific heat of fusion for water is 333 kilojoules per kilogram.  So if you took ice at exactly freezing point and dropped it 1km, converting all that energy into melting the ice, about 3% of it would melt.
Title: Re: Stupid Questions : Hydrokinetic energy
Post by: Shared Humanity on December 18, 2016, 06:34:44 PM
Does anyone know of a paper or discussion on the heat energy of falling water in the cryosphere?

The power of falling water is given as P = ηpQgh where

η = efficiency factor, percentage efficiency expressed as a decimal
P = power in Watts
p = density of the water
Q = flow rate in cubic meters/second
g = gravitational acceleration
h = head in meters (difference between inlet and outlet levels)

For ice, as for turbines, an efficiency factor is needed. When water flows over ice or falls through it, heat is generated at each disturbance in the flow.  This heat is less than would be generated by water falling unimpeded.

My point is that water flowing over ice or through it into the sea must be heated to at least some degree on its downward journey.  This will likely promote melting of glacier ice and / or promote local sea temperature rise.

So, has this been discussed anywhere?

If it isn't, I'd sure visit the thread if it was. Could you start the conversation in the Science section?
Title: Re: Stupid Questions :o
Post by: Shared Humanity on December 18, 2016, 06:37:57 PM
I can't lay my hands or eyes on the sources, but I am pretty sure that the splitting of methane in the atmosphere is rate limited by the hydroxyl radical. 

Found some    http://www.annualreviews.org/doi/abs/10.1146/annurev.pc.39.100188.002055?journalCode=physchem (http://www.annualreviews.org/doi/abs/10.1146/annurev.pc.39.100188.002055?journalCode=physchem)
Quote
Ann. Rev. Phys. Chern. 1988. 39: 367-94
KINETICS OF RADICAL REACTIONS IN THE ATMOSPHERIC OXIDATION OF CH4   1

Quote
A R. Ravishankara Aeronomy Laboratory, National Oceanic and Atmospheric Administration,Boulder,Colorado 80303

Shame it is not opensource   DOI: 10.1146/annurev.pc.39.100188.002055  Especially shameful as footnote one states
1 The US Government has the right to retain a nonexclusive, royalty-free license ...

Copy and paste not working on the pdf  Highlights  - 30% of the carbon monoxide is from CH4 oxidation.    The photolysis of methane is unimportant below the mesoshpere. 

Anyone finding a newer and or better distillation of methane atmospheric oxidation and posting it would be a stellar individual..  Possibly post into the Methane thread with the excitable name.  peace out

Could this be a safe way of geoengineering elevated levels of CH4 in the atmosphere? I'm fairly certain we have unzipped a lot of sources for methane that will be difficult to shut down.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on December 18, 2016, 06:41:02 PM
Oh, and thanks to everyone who responded to my stupid question. I understand a little more.
Title: Re: Stupid Questions :o
Post by: logicmanPatrick on December 18, 2016, 07:35:38 PM
Shared Humanity: re falling water - I wonder if Neven could move my question and responses to a new thread?

Re: CH4 - I wonder if this helps - Global Methane Biogeochemistry, W S Reeburgh 2003

www.ess.uci.edu/~reeburgh/WSR%20TOG%202006.pdf (http://www.ess.uci.edu/~reeburgh/WSR%20TOG%202006.pdf)
Title: Re: Stupid Questions :o
Post by: Jim Williams on December 20, 2016, 02:30:57 PM
...
Fortunately we are much further from the sun than Venus... In other words, what happens on Venus is likely to stay on Venus. :)

Thanks FTB et al.  Its reassuring to know that we are not going there, yet. 

But I am reminded, as I see my aircraft's wings flexing up and taking the load on takeoff, the 'laws of nature' do not need a peer reviewed paper to allow then to kick into action do they.

So in this prevailing situation where things are clearly out of balance, with unusual atmospheric heat entering the Arctic close to the surface combined with a drastically high water content in the air column which is doing its absorption thing (including about half of the radiation from the air column being scattered back downwards), then the positive reinforcement processes of more heat in wet air enables higher-still water content in the air which leads back to more more heat close to the surface and around we go - is in play as we speak isn't it.   There is no threshold above//below which these processes kick in - they are working now.

Ditto of course regarding kilometre scale methane plume eruptions due to warming oceans and the high short term GHG impact of methane, and no doubt there are several other similar feedback loops.

So in individual cells at micro and macro scale the Arctic climate is being driven by a number of forcings and as a consequence the climate is - within some pretty distant bounds - potentially in a run-away mode until it hits some limit.  Not a comfortable situation.

I thought I'd bring this up as a stupid question, since it isn't about the freezing season...

Regarding "potentially in a run-away mode until it hits some limit":  Just would would form that limit?  A cloudy Earth?
Title: Re: Stupid Questions :o
Post by: logicmanPatrick on December 20, 2016, 03:19:48 PM
Quote
Regarding "potentially in a run-away mode until it hits some limit":  Just would would form that limit?  A cloudy Earth?
I am currently reading up on increased precipitation and carbon cycles.  I have found info on the way that increased CO2 produces increased water uptake, hence increased precipitation.  Increased precipitation as rain appears to be good for plants -
http://earthobservatory.nasa.gov/Features/CarbonHydrology/ (http://earthobservatory.nasa.gov/Features/CarbonHydrology/)

Another factor which I am considering is the uptake of CO2 in rain.  Pure water rapidly absorbs CO2.  Rain would seem to take CO2 from the atmosphere and conduct it into aquifers, rivers and oceans.

Does anyone have any info to quantify this CO2 sink?
Title: Re: Stupid Questions :o
Post by: Tigertown on December 20, 2016, 03:54:24 PM
That is some sink. The moisture is causing runaway fungus growth that is deadly and the CO2 is making bodies of water deadly.
Title: Re: Stupid Questions :o
Post by: Jim Williams on December 21, 2016, 02:26:18 AM
Quote
Regarding "potentially in a run-away mode until it hits some limit":  Just would would form that limit?  A cloudy Earth?
I am currently reading up on increased precipitation and carbon cycles.  I have found info on the way that increased CO2 produces increased water uptake, hence increased precipitation.  Increased precipitation as rain appears to be good for plants -
http://earthobservatory.nasa.gov/Features/CarbonHydrology/ (http://earthobservatory.nasa.gov/Features/CarbonHydrology/)

Another factor which I am considering is the uptake of CO2 in rain.  Pure water rapidly absorbs CO2.  Rain would seem to take CO2 from the atmosphere and conduct it into aquifers, rivers and oceans.

Does anyone have any info to quantify this CO2 sink?

So you think that Co2 -> H2O -> less Co2 -> end of excess heat?

I might buy into this, but it seems to me the (H2O -> less C02) is likely to be a very slow part of the cycle.
Title: Re: Stupid Questions :o
Post by: Jim Williams on December 21, 2016, 02:28:32 AM
That is some sink. The moisture is causing runaway fungus growth that is deadly and the CO2 is making bodies of water deadly.

A mere detail.  I always have trouble with that "end of the Earth" nonsense.  The Earth couldn't care less if we live or die, and it is nowhere near ending.
Title: Re: Stupid Questions :o
Post by: Tigertown on December 21, 2016, 03:07:49 AM
I don't know about all that. Something being deadly does not mean necessarily that it will kill every living thing on Earth, but what it does kill is dead, nevertheless. Plus, the fungus stinks. It is killing snakes, which some people are probably happy about, though I am sure that even snakes serve a purpose, unless the fungus kills rats too. More than likely the rats and roaches will eat the fungus and thrive. So maybe at the very least, in the near future, we are looking  at a bunch of unpleasant  imbalances.
Title: Re: Stupid Questions :o
Post by: budmantis on December 21, 2016, 06:40:05 AM
That is some sink. The moisture is causing runaway fungus growth that is deadly and the CO2 is making bodies of water deadly.

A mere detail.  I always have trouble with that "end of the Earth" nonsense.  The Earth couldn't care less if we live or die, and it is nowhere near ending.

I agree with the last sentence of your post, but why do you think TT's post is suggesting an "end of the earth" scenario?
Title: Re: Stupid Questions :o
Post by: Phil. on December 21, 2016, 02:30:17 PM
Quote
Regarding "potentially in a run-away mode until it hits some limit":  Just would would form that limit?  A cloudy Earth?
I am currently reading up on increased precipitation and carbon cycles.  I have found info on the way that increased CO2 produces increased water uptake, hence increased precipitation.  Increased precipitation as rain appears to be good for plants -
http://earthobservatory.nasa.gov/Features/CarbonHydrology/ (http://earthobservatory.nasa.gov/Features/CarbonHydrology/)

Another factor which I am considering is the uptake of CO2 in rain.  Pure water rapidly absorbs CO2.  Rain would seem to take CO2 from the atmosphere and conduct it into aquifers, rivers and oceans.

Does anyone have any info to quantify this CO2 sink?

About 5x10^14 m^3 p.a. of rain globally.  The solubility of CO2 in fresh water is ~2 gms/l or 2kg/m^3 at 15ºC and 1atm partial pressure so that would be ~10^15x0.0004 kg/yr or 4x10^8 tonnes/yr. If my calculations are right that's about 5% of fossil fuel CO2 production.  Of course it's unlikely that it's all permanently sequestered. HTH
Title: Re: Stupid Questions :o
Post by: logicmanPatrick on December 21, 2016, 07:00:35 PM
Thanks for the replies.

Phil - those numbers are very useful, thanks.
Title: Re: Stupid Questions :o
Post by: Rattle on January 03, 2017, 08:47:36 AM
Are there any good charts or resources looking at sea ice changes in terms of energy budgets, as in how many joules were transferred in freezing or melting ice, how much solar energy is reflected given the state of sea ice and season at a point in time, and how much ghgs have affected loss of energy from the atmosphere to space?
Title: Re: Stupid Questions :o
Post by: Tigertown on January 03, 2017, 08:52:30 AM
Are there any good charts or resources looking at sea ice changes in terms of energy budgets, as in how many joules were transferred in freezing or melting ice, how much solar energy is reflected given the state of sea ice and season at a point in time, and how much ghgs have affected loss of energy from the atmosphere to space?
This might get you started, but not sure it will answer all your questions. Main article is a little dated, but you will find other info on the site.
https://www.researchgate.net/publication/229038139_Global_energy_accumulation_and_net_heat_emission (https://www.researchgate.net/publication/229038139_Global_energy_accumulation_and_net_heat_emission)
Title: Re: Stupid Questions :o
Post by: sidd on January 03, 2017, 09:33:57 PM
Re: heat flux from solar absorption poleward of 50 degrees

http://www.the-cryosphere-discuss.net/tc-2016-279/ (http://www.the-cryosphere-discuss.net/tc-2016-279/)
Title: Re: Stupid Questions :o
Post by: Paddy on January 09, 2017, 06:37:06 AM
Can anyone link me to a good summary of the trends in the amount of multi-year Arctic sea ice?

Or, for that matter, of the trends in northern hemisphere snow cover?
Title: Re: Stupid Questions :o
Post by: Pmt111500 on January 09, 2017, 06:50:29 AM
Can anyone link me to a good summary of the trends in the amount of multi-year Arctic sea ice?

Or, for that matter, of the trends in northern hemisphere snow cover?
Short answers.
Approaching zero. :-\ ??? :'(
Rutgers' snow lab had monthly figures of trends at one point in time, not sure anymore. It may be they've buried them somewhere in the anticipation of denialist governement. >:(
Title: Re: Stupid Questions :o
Post by: crandles on January 09, 2017, 01:34:03 PM
Can anyone link me to a good summary of the trends in the amount of multi-year Arctic sea ice?

Or, for that matter, of the trends in northern hemisphere snow cover?

Perhaps Figure 4 of
http://www.mdpi.com/2072-4292/8/6/457 (http://www.mdpi.com/2072-4292/8/6/457)

For snow extent, yes Rutgers still has graphs and tables of data at the moment:

http://climate.rutgers.edu/snowcover/ (http://climate.rutgers.edu/snowcover/)
Title: Re: Stupid Questions :o
Post by: Neven on January 09, 2017, 08:20:57 PM
Can anyone link me to a good summary of the trends in the amount of multi-year Arctic sea ice?

See below.

Quote
Or, for that matter, of the trends in northern hemisphere snow cover?

From Rutgers Global Snow Lab (http://climate.rutgers.edu/snowcover/):

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fclimate.rutgers.edu%2Fsnowcover%2Fimages%2Fnhland_season2.gif&hash=8b69d51d8e8d2655f32298af7b081081)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fclimate.rutgers.edu%2Fsnowcover%2Fimages%2Fnhland_season4.gif&hash=23b8fc05278af88ca75920f472d6e90b)

(https://forum.arctic-sea-ice.net/proxy.php?request=http%3A%2F%2Fclimate.rutgers.edu%2Fsnowcover%2Fimages%2Fnhland_season1.gif&hash=f63c8bb9aa6b929eb029483bf64eaca4)
Title: Re: Stupid Questions :o
Post by: anotheramethyst on January 09, 2017, 10:53:34 PM
Can anyone link me to a good summary of the trends in the amount of multi-year Arctic sea ice?

Or, for that matter, of the trends in northern hemisphere snow cover?
Short answers.
Approaching zero. :-\ ??? :'(
Rutgers' snow lab had monthly figures of trends at one point in time, not sure anymore. It may be they've buried them somewhere in the anticipation of denialist governement. >:(

In the US?  I thought we always had a denialist government.....  Remember when Obama didn't even bother to show up at the Durban climate talks and the only thing the world heard from the US government was a speech (via video uplink) from one of those denialist Republicans?  Good times.  (sarc)

Seriously, though, I was pissed.  He did eventually make it to Paris, but is anyone really impressed with this new climate deal?  Everything the government has ever done to fight climate change, when it has bothered to do anything, has been embarrassingly little and far too late to matter.  The only good thing about having a Republican in charge is it might motivate the left to actually do something for themselves rather than assuming the president will fix it, because he won't. 
Title: Re: Stupid Questions :o
Post by: shmengie on January 09, 2017, 11:18:55 PM
I'm full of stupid questions. . .  Hope this is the right place to ask 'em.

As I understand from NOAA & NASA information, the sea level are rising.  Its attributed primarily to melting land locked ice, as the Earth becomes warmer.

Sea level is also affected by water temperature and the expansion of water molecules as liquids become warmer.

I don't know at which point there will be enough water to cover every scrap of Earth, up to zero.zero land mass.

Two questions:

Would Mt. Everest be the last surviving point of Earth if the oceans continue to expand and swallow everything?

How long at the current warming trends/trajectory until this happens?


I asked NASA the same questions, wonder if I'll get a reply...   I want a simple equation so I can chart the date of ground point zero, based on current CO₂ production and projected date.

I expect it's a long way off into the future and may not be a realistic possibility,..  But as I understand its the most drastic outcome of current trends.  I'm guessing a mean ocean temperature increase of ~ 6C might do it, but that's a wild guess.
Title: Re: Stupid Questions :o
Post by: Neven on January 09, 2017, 11:27:01 PM
Don't move to Mt Everest just yet, shmengie.  ;)

I believe that even if all the ice melted on the planet, sea level can't rise more than 80 metres, thermal expansion included.
Title: Re: Stupid Questions :o
Post by: magnamentis on January 09, 2017, 11:30:12 PM
with the current topography there is not sufficient water on this planet to cover the entire land mass. this could only happen should all high elevations dissolve and fill the deeper seabeds to build a more or less homogeneous surface with few or no throughs and no significant mountains.

considering the current state of the planet with tectonic and volcanic activities this cannot be expected and even once that activities would all stop (like on mars) it would take hundreds of millions of years to drag the mountain's material off (corrosion) and spread it over the rest of the planet to fill the valleys and canyons, mostly those below current sea-level of course :-)

hence it's what one could call a non-topic, it's well possible that the coming "red giant" will be faster to make an appearance than all that will happen and at that point there will be no liquid water left due to the heat.
Title: Re: Stupid Questions :o
Post by: Tigertown on January 09, 2017, 11:30:25 PM
Agree.That will not happen. There is so much land that is so far above sea level that it won't be covered if all the ice melts. Plus, places like Greenland will rebound and reach higher elevations without so much ice  pushing downward.
Title: Re: Stupid Questions :o
Post by: crandles on January 10, 2017, 12:06:38 AM
Don't move to Mt Everest just yet, shmengie.  ;)

I believe that even if all the ice melted on the planet, sea level can't rise more than 80 metres, thermal expansion included.

I thought thermal expansion was not included in the 80m for melting all ice. Think there is a suggestion of +120m sea levels for early eocene:
http://static.springer.com/sgw/documents/650498/application/pdf/978-1-4020-4551-6_Sea+Level+Change,+Last+250+Million+Years_Miller_web.pdf (http://static.springer.com/sgw/documents/650498/application/pdf/978-1-4020-4551-6_Sea+Level+Change,+Last+250+Million+Years_Miller_web.pdf)

p885 blue line and blue scale if I am understanding that.
Title: Re: Stupid Questions :o
Post by: Valdemar on January 10, 2017, 12:23:22 AM
If you want a taste of a true flooded Earth, I'd read Flood by Stephen Baxter instead.

I always saw sea level rise as being somewhat less of an issue over, say, general climate erraticness causing problems for agriculture.
Title: Re: Stupid Questions :o
Post by: AbruptSLR on January 10, 2017, 12:32:39 AM
Don't move to Mt Everest just yet, shmengie.  ;)

I believe that even if all the ice melted on the planet, sea level can't rise more than 80 metres, thermal expansion included.

I thought thermal expansion was not included in the 80m for melting all ice. Think there is a suggestion of +120m sea levels for early eocene:
http://static.springer.com/sgw/documents/650498/application/pdf/978-1-4020-4551-6_Sea+Level+Change,+Last+250+Million+Years_Miller_web.pdf (http://static.springer.com/sgw/documents/650498/application/pdf/978-1-4020-4551-6_Sea+Level+Change,+Last+250+Million+Years_Miller_web.pdf)

p885 blue line and blue scale if I am understanding that.

It is my recollection that some of the water (about 40-meters worth) has moved underground subsequent to the Eocene and that it would take significant volcanic activity to get it to resurface.
Title: Re: Stupid Questions :o
Post by: Paddy on January 10, 2017, 01:27:08 AM
Thank you Neven, those graphs are awesome
Title: Re: Stupid Questions :o
Post by: Tigertown on January 10, 2017, 02:33:34 AM
Glad that I live on a Piedmont Plateau known here as The Piedmont Plateau, as it about 330 m above sea level. And the foods ok, too. ;)
Title: Re: Stupid Questions :o
Post by: budmantis on January 10, 2017, 07:53:50 AM
I live in Zephyrhills, Florida. About twenty five miles northeast of Tampa. The closest height of land for us is Leheup Hill, about five miles north of here, at a whopping 240 feet above sea level. That should be sufficient if Greenland melts entirely, although it would require a ferry to get to the mainland!
Title: Re: Stupid Questions :o
Post by: Jim Pettit on January 10, 2017, 02:38:54 PM
If you want a taste of a true flooded Earth, I'd read Flood by Stephen Baxter instead.

I always saw sea level rise as being somewhat less of an issue over, say, general climate erraticness causing problems for agriculture.

As a resident of South Florida, living in a home situated atop an ancient sandbar positioned between the rising Gulf and the soon-to-be-flooded Everglades, sea level rise is most definitely near the top of my personal list of concerns. ;-)
Title: Re: Stupid Questions :o
Post by: kiwichick16 on January 10, 2017, 03:26:05 PM
@  Jim....get out while your house is still worth something.......nobody knows when the run on the bank will start but the smart money gets out first
Title: Re: Stupid Questions :o
Post by: RoxTheGeologist on January 10, 2017, 04:01:47 PM
If you want a taste of a true flooded Earth, I'd read Flood by Stephen Baxter instead.

I always saw sea level rise as being somewhat less of an issue over, say, general climate erraticness causing problems for agriculture.

As a resident of South Florida, living in a home situated atop an ancient sandbar positioned between the rising Gulf and the soon-to-be-flooded Everglades, sea level rise is most definitely near the top of my personal list of concerns. ;-)

Florida is on a 50 year lease from the ocean...
Title: Re: Stupid Questions :o
Post by: mhampton on January 10, 2017, 04:08:10 PM
I live in Zephyrhills, Florida. About twenty five miles northeast of Tampa. The closest height of land for us is Leheup Hill, about five miles north of here, at a whopping 240 feet above sea level. That should be sufficient if Greenland melts entirely, although it would require a ferry to get to the mainland!

I wonder how long such Florida islands will last after a hurricane or two.  How far below is the bedrock?
Title: Re: Stupid Questions :o
Post by: RoxTheGeologist on January 10, 2017, 04:21:27 PM

After a quick look at the map,  50% of Florida, the south and the west, are comprised of Quaternary dunes/limestone. My guess is that it is largely porous to water. It will make flood defenses difficult to construct.

Pretty much the whole of Florida is later Cenozoic sedimentary, so young (ish). It's not like building homes on Granite.
Title: Re: Stupid Questions :o
Post by: jdallen on January 10, 2017, 05:51:50 PM

After a quick look at the map,  50% of Florida, the south and the west, are comprised of Quaternary dunes/limestone. My guess is that it is largely porous to water. It will make flood defenses difficult to construct.

Pretty much the whole of Florida is later Cenozoic sedimentary, so young (ish). It's not like building homes on Granite.
Flood defenses are *impossible* to construct. Miami is a poster child for that.  Water stacking up anywhere *will* redistribute itself. The only thing to do is go up, and drive something amphibious...
Title: Re: Stupid Questions :o
Post by: magnamentis on January 10, 2017, 06:18:49 PM
I live in Zephyrhills, Florida. About twenty five miles northeast of Tampa. The closest height of land for us is Leheup Hill, about five miles north of here, at a whopping 240 feet above sea level. That should be sufficient if Greenland melts entirely, although it would require a ferry to get to the mainland!

perhaps sufficient for an elevation but not to take on the entire population from that area once that only a tiny "bump" will stick out of the water :-) i think it's safe to say that not too far in the future one has to forget about most of florida as a livable place, at least the southern half or so.
Title: Re: Stupid Questions :o
Post by: ktonine on January 10, 2017, 10:44:58 PM
I live in Zephyrhills, Florida. About twenty five miles northeast of Tampa.

My work takes me down to Dade City usually at least once a year - we have a small lab there.  So I've seen the Zephyrhills signs many times - though I don't know if I've ever actually been there.
Title: Re: Stupid Questions :o
Post by: budmantis on January 11, 2017, 07:30:00 AM
If you want a taste of a true flooded Earth, I'd read Flood by Stephen Baxter instead.

I always saw sea level rise as being somewhat less of an issue over, say, general climate erraticness causing problems for agriculture.

As a resident of South Florida, living in a home situated atop an ancient sandbar positioned between the rising Gulf and the soon-to-be-flooded Everglades, sea level rise is most definitely near the top of my personal list of concerns. ;-)

Jim, have you ever visited the Bok Tower in Lake Wales? It sits on the highest point on the Florida peninsula at 298 feet above sea level.
Title: Re: Stupid Questions :o
Post by: budmantis on January 11, 2017, 07:51:04 AM

perhaps sufficient for an elevation but not to take on the entire population from that area once that only a tiny "bump" will stick out of the water :-) i think it's safe to say that not too far in the future one has to forget about most of florida as a livable place, at least the southern half or so.

A "bump" sticking out of the water is a good analogy Magnamentis. I think all of So. Florida would be underwater if Greenland were to melt completely. All that would be left would likely be half a dozen islands, and the panhandle.
Title: Re: Stupid Questions :o
Post by: budmantis on January 11, 2017, 07:55:12 AM
I live in Zephyrhills, Florida. About twenty five miles northeast of Tampa.

My work takes me down to Dade City usually at least once a year - we have a small lab there.  So I've seen the Zephyrhills signs many times - though I don't know if I've ever actually been there.

Dade City is a really nice place. My wife and I enjoy going up there for the Kumquat festival and other activities. Zephyrhills is about ten miles south on Rt. 301.
Title: Re: Stupid Questions :o
Post by: anotheramethyst on January 11, 2017, 08:43:13 AM
I live in the Midwest so I'm safe from sea level rise, but my home town, where my parents live is on the Texas coast.  It doesn't get as much press as Florida, but the average sea level for the entire coastal plain of Texas is 1 foot of elevation.  So I'm trying to talk my parents into moving.  I don't think they have to wait for much of Greenland to melt to be underwater.  Like I said, it doesn't get much press, probably because so much of it is nearly unpopulated.  (When hurricane Allen literally flattened half my town in 1980, it flooded everything, every building was immersed in the entire town.  Half the buildings were completely destroyed.  You can read about it on wikipedia today, where it describes all the damage as "luckily it hit an unpopulated area."  Thanks for the sympathy, wikipedia!  )
Title: Re: Stupid Questions :o
Post by: Phil. on January 11, 2017, 01:31:17 PM
If you want a taste of a true flooded Earth, I'd read Flood by Stephen Baxter instead.

I always saw sea level rise as being somewhat less of an issue over, say, general climate erraticness causing problems for agriculture.

As a resident of South Florida, living in a home situated atop an ancient sandbar positioned between the rising Gulf and the soon-to-be-flooded Everglades, sea level rise is most definitely near the top of my personal list of concerns. ;-)

Jim, have you ever visited the Bok Tower in Lake Wales? It sits on the highest point on the Florida peninsula at 298 feet above sea level.

It's quite an impressive place, I went there with my daughter and granddaughter last year.
Title: Re: Stupid Questions :o
Post by: magnamentis on January 11, 2017, 01:41:32 PM
that would be an example + the link to calculate other values:

http://geology.com/sea-level-rise/ (http://geology.com/sea-level-rise/)



Title: Re: Stupid Questions :o
Post by: RoxTheGeologist on January 11, 2017, 03:55:35 PM
I live in the Midwest so I'm safe from sea level rise, but my home town, where my parents live is on the Texas coast.  It doesn't get as much press as Florida, but the average sea level for the entire coastal plain of Texas is 1 foot of elevation.  So I'm trying to talk my parents into moving.  I don't think they have to wait for much of Greenland to melt to be underwater.  Like I said, it doesn't get much press, probably because so much of it is nearly unpopulated.  (When hurricane Allen literally flattened half my town in 1980, it flooded everything, every building was immersed in the entire town.  Half the buildings were completely destroyed.  You can read about it on wikipedia today, where it describes all the damage as "luckily it hit an unpopulated area."  Thanks for the sympathy, wikipedia!  )

River valleys are very prone to flooding during periods of sea level rise. It's not just the coast line.
St Paul, in Minnesota, is only at an elevation of 702', It's on the Mississippi, and 1000 miles from the ocean. We will see huge incursion of sea water up the valley and extensive flooding in areas of the Midwest that are close to rivers.
Title: Re: Stupid Questions :o
Post by: Laurent on January 11, 2017, 07:10:49 PM
For the moment we are on our way for 50 meters, can we have more ? I don't know, I have a doubt about the reliability of these graphs... (I am not talking of the graph with CO2-temp-SLR)
Title: Re: Stupid Questions :o
Post by: Tigertown on January 11, 2017, 11:51:36 PM
As these are sending waves into the Arctic, I guess that makes my question relevant. Re: Huge areas of disturbances which are causing large waves, as seen on links.

https://earth.nullschool.net/#current/ocean/primary/waves/overlay=significant_wave_height/orthographic=-12.15,57.45,1100/loc=-8.518,63.993

https://earth.nullschool.net/#current/ocean/primary/waves/overlay=significant_wave_height/orthographic=-193.33,39.44,1100/loc=177.804,35.207

Have these always been normal for this time of year, and as frequent and plentiful as these are currently?
Title: Re: Stupid Questions :o
Post by: Darvince on January 12, 2017, 03:25:14 AM
that would be an example + the link to calculate other values:

http://geology.com/sea-level-rise/ (http://geology.com/sea-level-rise/)

If you want a website to calculate any value of sea level rise (keep in mind from ice alone the highest we can expect is about 75 meters, and if the entire water column globally reached 20C then we could add another 20 meters on top of that, for a total of 95 meters in the worst case scenario).

http://www.heywhatsthat.com/layers.html (http://www.heywhatsthat.com/layers.html)

Greenland fully melting out should be about 7 meters, although I would expect an ice-free West Antarctica long before an ice-free Greenland because of WAIS's lack of large mountains along its rim...
Title: Re: Stupid Questions :o
Post by: johnm33 on January 12, 2017, 11:05:53 AM
"Have these always been normal for this time of year, and as frequent and plentiful as these are currently?"
That area of the Atlantic is notorious for giant waves. I suspect the bathymetry has a hand in it. http://topex.ucsd.edu/marine_topo/jpg_images/topo4.jpg (http://topex.ucsd.edu/marine_topo/jpg_images/topo4.jpg)
One of my own, with such a massive low in the Arctic how much water is going to be drawn in from surrounding oceans?
[edit ans] http://weather.mailasail.com/Franks-Weather/Pressure-And-Tides (http://weather.mailasail.com/Franks-Weather/Pressure-And-Tides)
Title: Re: Stupid Questions :o
Post by: magnamentis on January 13, 2017, 06:59:46 PM
that would be an example + the link to calculate other values:

http://geology.com/sea-level-rise/ (http://geology.com/sea-level-rise/)

If you want a website to calculate any value of sea level rise (keep in mind from ice alone the highest we can expect is about 75 meters, and if the entire water column globally reached 20C then we could add another 20 meters on top of that, for a total of 95 meters in the worst case scenario).

http://www.heywhatsthat.com/layers.html (http://www.heywhatsthat.com/layers.html)

Greenland fully melting out should be about 7 meters, although I would expect an ice-free West Antarctica long before an ice-free Greenland because of WAIS's lack of large mountains along its rim...

sincere thanks for that link, i found plenty but didn't have time to find the best which that one is as far as i can see. very much appreciated and bookmarked :-)

nice weekend @all
Title: Re: Stupid Questions :o
Post by: shmengie on January 15, 2017, 05:11:09 AM
OMG, I gotta think a bout stupid questions, why?

Trash to steam used to be a "thing".  I can remember thinking it wasn't necessarily a bad idea.  I don't remember it becoming a non-thing.  As best I can recall, after recycling in the US became popular, I haven't heard about it.

I can't help, but believe, it was a CO₂ nightmare.  Guess we're not entirely stupid.

Is that what happened to trash-to-steam?  Bad idea and we got smart enough to end the habbit?
Title: Re: Stupid Questions :o
Post by: logicmanPatrick on January 15, 2017, 06:26:01 AM
shmengie: it's fairly normal now to use trash to make electricity, so it doesn't get much attention in blogs and media.  That said, the link below is from August 2016, so some people are still paying attention.  ;D

https://thinkprogress.org/burning-trash-to-create-energy-the-complicated-journey-to-zero-waste-9d6576ad55fd#.k0zmuqmjp
Title: Re: Stupid Questions :o
Post by: Hefaistos on January 15, 2017, 10:38:02 AM
Thanks for the link to that article. It's very extensive regarding environmental impact of trash burning facilities. But it doesn't even mention emissions of carbon dioxide, although more than 30% of trash is organic matter.
Interestingly, landfills are known emitters of methane, but burning trash supposedly puts a lot of CO2 directly into the atmosphere.
Meanwhile, global population grows from 7.5 billion to 10+ billion already 2050, creating ever more trash.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on January 15, 2017, 04:30:49 PM
When looking at trash, its impact on the local environment (landfills etc.) and global (CH4 and CO2 emissions) the only real solution is source reduction. We must reduce the amount of trash we produce.
Title: Re: Stupid Questions :o
Post by: RoxTheGeologist on January 15, 2017, 07:19:30 PM

There is a company in California that is using the locally collected trash in a biodigester, making methane and using it to power the trash trucks - this is a much better use than incinerating as you don't have to deal with the other nasty pollutants that come from burning household waste.

I really like this model as the Carbon is kept local. Your waste powers the trucks that pick up your trash.


On a negative side, the biowaste facilities in California will probably stop making energy from biomass as they have to pay Cap and Trade Carbon taxes (for some obscure reason)
Title: Re: Stupid Questions :o
Post by: Tigertown on January 15, 2017, 07:31:51 PM
Help, please! How do you get to the Arctic forecast on Tropical Tidbits, as I can't find it anywhere? Maybe I have an old outdated link.
Title: Re: Stupid Questions :o
Post by: DrTskoul on January 15, 2017, 07:34:40 PM
Help, please! How do you get to the Arctic forecast on Tropical Tidbits, as I can't find it anywhere? Maybe I have an old outdated link.

http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=nhem&pkg=mslp_pcpn_frzn&runtime=2017011512&fh=6 (http://www.tropicaltidbits.com/analysis/models/?model=gfs&region=nhem&pkg=mslp_pcpn_frzn&runtime=2017011512&fh=6)

Title: Re: Stupid Questions :o
Post by: Tigertown on January 15, 2017, 07:39:49 PM
Thanks. I will bookmark it now.
Do they have only the GFS for the Arctic or do they also have the ECMWF?
Title: Re: Stupid Questions :o
Post by: Neven on January 15, 2017, 07:57:06 PM
Go to 'Forecast Models'. When you click 'Global', you can choose what forecast model you want to use. Then, below the map, click 'Regions', and there you can choose 'Northern Hemisphere'.

That's how I do it.
Title: Re: Stupid Questions :o
Post by: DrTskoul on January 15, 2017, 08:08:02 PM
Go to 'Forecast Models'. When you click 'Global', you can choose what forecast model you want to use. Then, below the map, click 'Regions', and there you can choose 'Northern Hemisphere'.

That's how I do it.

Exactly...I should have spent a few more seconds describing  ::)
Title: Re: Stupid Questions :o
Post by: Tigertown on January 15, 2017, 08:11:39 PM
Got it now. I have a feeling it's going to bear watching in the near future.
Title: Re: Stupid Questions :o
Post by: shmengie on January 19, 2017, 04:34:24 AM
Stupid question?

Cold floods into the atmosphere where it's thinnest, at the poles.

vortexes in the upper atmosphere direct the cold toward the Earth's surface.

When the vortex is disorganized does it cause the cold to get scattered un focused toward the poles?
(seems like its akin to a inverted boiling action, or is it?)

I think the tighter the organization of polar vortexes, the more focused heat dissipation is toward the poles, but I have no idea how to test the hypothesis.

(intended stupid question comming up, here:)

The el Nino factor, is that possibly brought about by heat pressure maintained by organized polar vertices's?
Title: Re: Stupid Questions :o
Post by: DrTskoul on January 19, 2017, 04:51:45 AM
Stupid question?

Cold floods into the atmosphere where it's thinnest, at the poles.

vortexes in the upper atmosphere direct the cold toward the Earth's surface.

When the vortex is disorganized does it cause the cold to get scattered un focused toward the poles?
(seems like its akin to a inverted boiling action, or is it?)

I think the tighter the organization of polar vortexes, the more focused heat dissipation is toward the poles, but I have no idea how to test the hypothesis.

(intended stupid question comming up, here:)

The el Nino factor, is that possibly brought about by pressure maintained by organized polar vertices's?

There are no stupid questions when one tries to learn.

I am by no means expert by I will try to give some useful information

Polar Easterlies (https://en.m.wikipedia.org/wiki/Polar_easterlies)

So normal higher gas density will allow the cold air to sink. It does not require vortices or earth rotation. Also normal conservation of mass will push air at the upper air elevations from mid latitudes to the poles.

Disorganization will happen when heat from the Arctic ocean or from Lowe's pressure systems meandering to the Arctic mess up with the natural sinking of the air. This will affect the polar easterlies and the jet stream. The best setup for heat dissipation is a stable polar high due to deep dry cold from an Arctic ocean covered by thick ice.

El Ninos affect the poles through a complex atmospheric and oceanic teleconnection. The strength of the coupling depends on the setup of the Hadley (tropic and polar) cells (https://en.m.wikipedia.org/wiki/Hadley_cell).
Title: Re: Stupid Questions :o
Post by: dnem on January 19, 2017, 01:07:47 PM
It seems to me (from various posts here) that the wind speeds associated with these storms in the arctic are quite a bit slower than a storm of similar low central pressure at mid-latitudes.  Is this true? And if so, why?  Thanks.
Title: Re: Stupid Questions :o
Post by: Tigertown on January 19, 2017, 04:54:14 PM
Are the NSIDC links moved are just experiencing tech problems?

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/NH_seaice_extent_nrt_v2.csv

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/south/daily/data/SH_seaice_extent_nrt_v2.csv
Title: Re: Stupid Questions :o
Post by: Mozi on January 19, 2017, 04:59:33 PM
The files may have been renamed? I see that there are files named 'N_seaice_extent_daily_v2.1.csv' and 'S_seaice_extent_daily_v2.1.csv', respectively.
Title: Re: Stupid Questions :o
Post by: bairgon on January 19, 2017, 05:29:38 PM
I see two these files:

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/N_seaice_extent_daily_v2.1.csv
 (ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/north/daily/data/N_seaice_extent_daily_v2.1.csv)

ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/south/daily/data/S_seaice_extent_daily_v2.1.csv (ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/south/daily/data/S_seaice_extent_daily_v2.1.csv)

Looks like they changed the names.

Noticed the NSIDC arctic sea ice news site at http://nsidc.org/arcticseaicenews/ (http://nsidc.org/arcticseaicenews/) has changed the maps and some fonts too.
Title: Re: Stupid Questions :o
Post by: Tigertown on January 19, 2017, 05:39:16 PM
@bairgon

Those first two you have there give the same message: this site can't be reached, blah,blah,blah.
Title: Re: Stupid Questions :o
Post by: Alphabet Hotel on January 19, 2017, 05:49:51 PM
@Tigertown

I can download those files.
Title: Re: Stupid Questions :o
Post by: bairgon on January 19, 2017, 06:16:44 PM
@bairgon

Those first two you have there give the same message: this site can't be reached, blah,blah,blah.

I did edit the message a few times, trying to get the correct format for ftp links. Perhaps you have an old version? My apologies - first time for everything on this forum...

Also took a little time to find the right files and folders.

I'm using FireFTP in Firefox, and it opens up the the folders with a directory listing which made it easy to see what had changed.
Title: Re: Stupid Questions :o
Post by: Tigertown on January 19, 2017, 06:22:16 PM
Thanks very much.
Title: Re: Stupid Questions :o
Post by: Wipneus on January 19, 2017, 06:52:26 PM
Are the NSIDC links moved are just experiencing tech problems?


They have moved , with some other changes as well:

https://nsidc.org/the-drift/data-update/sea-ice-index-ftp-directory-structure-changing/

On 31 Jan the ftp will be closed and all that data can only be accessed from the protected (user+password, free registration) https connection. Start here and find the rest:

https://daacdata.apps.nsidc.org/pub/DATASETS/NOAA/G02135/

etcetera.
Title: Re: Stupid Questions :o
Post by: Tigertown on January 19, 2017, 06:58:42 PM
Thanks Wipneus. I am sure that is news to more than just me.
Title: Re: Stupid Questions :o
Post by: Daniel on January 20, 2017, 12:43:33 PM
It seems to me that the only consequence of the disappearing sea ice that is being discussed is the albedo change. Of course the arctic waters will absorb more energy from the sun as the ice disappears (anyone have a number on that?).
BUT there is obviously already an enormous amount of heat in the arctic; heat that today goes into melting the ice. Say that the IceVolume trend is appr. -300 km3 per year.
To melt that volume of ice it takes about 90*10^15 kJ
So when the sea ice is gone, the heat that is no longer being used to melt ice will instead heat the water.
If that energy would go into heating the top one meter across the whole arctic sea (~14M km^2), that water would warm by about 1,5 degrees C. Per year.

Do you know of anyone discussing this and possible consequences in more detail?
Title: Re: Stupid Questions :o
Post by: shmengie on January 20, 2017, 11:13:19 PM
I'm fairly new to nullschool.  This configuration is new to me @ 10 hPa.

On the surface, the vortex in the center is a low pressure system and the vortices on either side are high.

Are they the same @ 10 hPa?
Title: Re: Stupid Questions :o
Post by: shmengie on January 21, 2017, 07:34:57 PM
I suppose I phrased my question wrong (dang my stupidity)... ;)

Instead of high pressure vs low pressure in cyclonic spin, is it a function of heat transport down vs. up?

Do low pressure systems spin counter clockwise in the northern hemisphere due to heat being transported up thru the center?

Conversely do clockwise spin in northern hemisphere indicate cold transport down @/thru the center?

 Thanks for the wonderful response to my other stupid questions, BTW!
Title: Re: Stupid Questions :o
Post by: nicibiene on January 21, 2017, 08:06:15 PM
Found yesterday in my newspaper an article regarding icicles which mentioned an underwater salty version, brinicles. Got curious if it could be also an effect on oceanic life and thermohaline circulation in the arctic as it is getting warmer and more stormy.

Brinicles are transporting a lot of iones and iciness down to lower levels. They need silent waters and certain gradients in temperature. If there is more stormy and warmer water the system is getting disrupted.

Maybe it is one thing that made methane hydrates and it already affects the gulfstream from North?
 In the linked article is to find a hint towards that thought:

"The exchange of salt between sea ice and the ocean influences ocean circulation across hundreds of kilometers. "

http://www.dailykos.com/story/2016/3/6/1493086/-IAN-Monday-March-7-2016-Underwater-Icicle-of-Death-Brinicle (http://www.dailykos.com/story/2016/3/6/1493086/-IAN-Monday-March-7-2016-Underwater-Icicle-of-Death-Brinicle)


Title: Re: Stupid Questions :o
Post by: aslan on January 21, 2017, 08:50:13 PM
I suppose I phrased my question wrong (dang my stupidity)... ;)

Instead of high pressure vs low pressure in cyclonic spin, is it a function of heat transport down vs. up?

Do low pressure systems spin counter clockwise in the northern hemisphere due to heat being transported up thru the center?

Conversely do clockwise spin in northern hemisphere indicate cold transport down @/thru the center?

 Thanks for the wonderful response to my other stupid questions, BTW!

There is no direct link between stratosphere and troposphere. When you will know more about the subject you will see how troposphere and stratophere are connected, but by the way I strongly suggest you starting with the point of view that there is not such thing as of a direct link between low pressure center in stratosphere and low pressure center in troposphere. And I even more strongly suggest that you don't refer to low pressure area, excepted at surface. This can lead to epic confusion and epic fail. Above surface, no matter it is troposphere and stratosphere, it is better to speak about low geopotential and high geopotential (there is others terms possible, depending at which kind of surface you are looking at, but low / high geopotenial is a good start). And more generally, don't try to make direct link between low geopotential area in stratosphere and troposphere. There is baroclinic and batropic waves. In the case of baroclinic wave, center of low geopotential area is displaced to the west with height. For the rest I am not sure to understund.

But to help you. There is the difference between baroclinic and barotropic waves indeed. In baroclinic waves, there is warm temperatures and high humidity to the equator, and low temperatures and low humidity to the pole. With the southerly flow downstream of the low, geopotential heights rise (air is at higher temperatures and higher humidity, so the air expands, hence the higher geopotential height). And with northerly flow upstream of the low, geopotentials heights lower. This is the case for an extratopical cyclone (at 500 hPa, the trough is "behind" the low at surface). But it is also the case for large scale waves. Currently, stratosphere is under assault by a wave of wavenumber 1. Usually, this is a baroclinic wave. But for now, the tilt toward the west with height is not really persuasive, and this does not lead to be overly optimistic about the chance of a SSW in the definition.
Conversely, barotropic waves are vertically aligned and there is no such thing as differential temperature/humidity advection. This is the case for tropical cyclones and polar low for example. But at a wider scale, planetary waves often tend to become barotropic -despite the gradients in the mid latitudes-. Also, wavenumber 2 in stratosphere is more usually a barotropic wave, which means it is vertically aligned. Wavenumber 2 assault against polar vortex often lead to a split case of SSW (polar vortex being broken in two piece so).
Title: Re: Stupid Questions :o
Post by: shmengie on January 21, 2017, 10:10:27 PM
Aslan, thank you for your explanation, I'm very interested in understanding several of the points you've made.  I will be reading soon, unfortunately, I need to be reading for my job, not my hobby...

I apologize for my ignorance, I've not studied meteorology in depth.  As I understand tropical cyclones always spin counter clockwise in the northern hemisphere and clockwise in the southern.  I assume this has to do with the direction of heat transport and magnetic fields.

I'm inclined to believe the upper atmosphere behaves similarly.  But I also fear my assumption is baseless.

Thats what I was fishing for, now I need to read, to see my postulations are anywhere near the right track...

In either event, thank you!
Title: Re: Stupid Questions :o
Post by: dnem on January 22, 2017, 01:59:10 PM
As I understand tropical cyclones always spin counter clockwise in the northern hemisphere and clockwise in the southern.  I assume this has to do with the direction of heat transport and magnetic fields.

It has do with the direction of the pressure gradient and the Coriolis force.


http://www.aoml.noaa.gov/hrd/tcfaq/D3.html (http://www.aoml.noaa.gov/hrd/tcfaq/D3.html)
Why do tropical cyclones' winds rotate counter-clockwise (clockwise) in the Northern (Southern) Hemisphere?

The reason is that the earth's rotation sets up an apparent force (called the Coriolis force) that pulls the winds to the right in the Northern Hemisphere (and to the left in the Southern Hemisphere). So when a low pressure starts to form north of the equator, the surface winds will flow inward trying to fill in the low and will be deflected to the right and a counter-clockwise rotation will be initiated. The opposite (a deflection to the left and a clockwise rotation) will occur south of the equator.
Title: Re: Stupid Questions :o
Post by: aslan on January 22, 2017, 01:59:36 PM
Aslan, thank you for your explanation, I'm very interested in understanding several of the points you've made.  I will be reading soon, unfortunately, I need to be reading for my job, not my hobby...

I apologize for my ignorance, I've not studied meteorology in depth.  As I understand tropical cyclones always spin counter clockwise in the northern hemisphere and clockwise in the southern.  I assume this has to do with the direction of heat transport and magnetic fields.

I'm inclined to believe the upper atmosphere behaves similarly.  But I also fear my assumption is baseless.

Thats what I was fishing for, now I need to read, to see my postulations are anywhere near the right track...

In either event, thank you!

The direction of the spin is imposed by the coriolis force only. In NH, cyclonic flow is counter-clockwise and anticyclonic flow is clockwise. The reverse is true for SH. Coriolis force is described by f, the coriolis frequency, such as :

f = 2 * ( earth rotation rate ) * sin( latitude )

And Earth rotation rate is 7.2921*10-5 s-1

For around 45°N (in radians, so pi/4), f is roughly equal to 1e-4 s-1, and for 45°S it is roughly equal to -1e-4 s-1. The change in sign is the only reason for the different direction of spin in NH and SH. You can also note that the multiplicative inverse of f, around 45°N or S still, is 3 hours approximately (10 000 seconds). This means that any flow lasting less than 3h will not feel the coriolis force. And given a standard speed of around 50 m/s (180 km/h), in 3 hours the flows will "travel" around 500 kilometers. This means that any flow lasting less than 3h and/or smaller than 500 kilometers will not feel the coriolis force. This is described by Rossby number :

Ro = speed / ( lengthscale * f )

If Ro < 1, the flow will be subject to Coriolis force. You can check that for example the flow in a bathtub will not be subject to Coriolis force.

In tropics, Coriolis frequency being small (and even nul at equator), flow are much rotationnal and much more divergent / convergent. Tropical cyclones are an exception, being very long lasting system and with very high wind speed. For example, in mid-latitudes, squall-lines have a lengthscale around 100 - 200 kilometers and are a the high end bounds of the mesoscale where Coriolis force remains marginal. In tropics, squall-lines can reach a lengthscale of up to 1000 kilometers and still being and still being at the high end bounds of the mesoscale where Coriolis force remains marginal.

There is no such thing as the geomagnetic field or differential temperatures advection in explaining the direction of the spin.
Title: Re: Stupid Questions :o
Post by: dnem on January 22, 2017, 05:17:13 PM


The direction of the spin is imposed by the coriolis force only.
[/quote]

Wouldn't it be correct to say that the direction is dependent on whether it is divergent or convergent flow?  Certainly the deflection due to coriolis is the same, but the result, cyclonic or anti-cyclonic, depends on the pressure differential that caused air flow in the first place?
Title: Re: Stupid Questions :o
Post by: Tigertown on January 22, 2017, 05:43:29 PM
Correct me if I am wrong aslan, but maybe where the miscommunication is coming from is in regard to the very definition of the term cyclone. Is every circulation in the atmosphere automatically to be called a cyclone? My thinking is no. Please enlighten.
Title: Re: Stupid Questions :o
Post by: aslan on January 23, 2017, 10:41:09 PM
Yeah yeah, of course cyclone is not spinning the same way in NH and SH. And if you dig in the etymology of the word cyclonic and anticyclonic, it is quite two strange words. Cyclone comes from Greek and does not implies a priori a specific direction for the spin. Etymologically speaking, we could make a case that anticyclonic is cyclonic... It is worth remembering also that we are speaking about vorticity along z-axis. Vorticity along x and y axis are negligible in general ( excepted in tornadoes XD ). And, mathematically speaking, positive vorticity is counter-clockwise, and negative vorticity is clockwise. This said, when I speak about a cyclone, for me it is a positive spin in NH and negative spin in SH. Of course, there is a link between the vorticity and the local pressure anomaly. If you consider p', the field of the pressure anomaly (anomaly regarding a space mean p0, not a time mean), you can write something like this -k and v vector- :

-1/ρ0 * grad( p' ) = f0 * k ⋀ v

Or more simply, in NH positive spin around a low pressure anomaly (1025 hPa can still be cyclonic if embedded in a 1050 hPa anticyclonic rotation ...) and a negative spin around a low pressure anomaly (again, 1000 hPa can be quite anticyclonic). I'm note sure if there is a best way to describe this equation. Coriolis force and pressure gradient act together and you have something like a double entry table. If NH and convergent flow, positive vorticity. If SH and convergent flow, negative vorticity. If NH and divergent flow, negative vorticity. If SH and convergent flow, positive vorticity.
Title: Re: Stupid Questions :o
Post by: magnamentis on January 23, 2017, 11:33:10 PM
Yeah yeah, of course cyclone is not spinning the same way in NH and SH. And if you dig in the etymology of the word cyclonic and anticyclonic, it is quite two strange words. Cyclone comes from Greek and does not implies a priori a specific direction for the spin. Etymologically speaking, we could make a case that anticyclonic is cyclonic... It is worth remembering also that we are speaking about vorticity along z-axis. Vorticity along x and y axis are negligible in general ( excepted in tornadoes XD ). And, mathematically speaking, positive vorticity is counter-clockwise, and negative vorticity is clockwise. This said, when I speak about a cyclone, for me it is a positive spin in NH and negative spin in SH. Of course, there is a link between the vorticity and the local pressure anomaly. If you consider p', the field of the pressure anomaly (anomaly regarding a space mean p0, not a time mean), you can write something like this -k and v vector- :

-1/ρ0 * grad( p' ) = f0 * k ⋀ v

Or more simply, in NH positive spin around a low pressure anomaly (1025 hPa can still be cyclonic if embedded in a 1050 hPa anticyclonic rotation ...) and a negative spin around a low pressure anomaly (again, 1000 hPa can be quite anticyclonic). I'm note sure if there is a best way to describe this equation. Coriolis force and pressure gradient act together and you have something like a double entry table. If NH and convergent flow, positive vorticity. If SH and convergent flow, negative vorticity. If NH and divergent flow, negative vorticity. If SH and convergent flow, positive vorticity.

thanks for the above, it's a pleasure to have an opportunity to learn such things as an aside, love it.
Title: Re: Stupid Questions :o
Post by: shmengie on January 24, 2017, 01:45:36 AM
+1

Would love to ask more questions, fear used up my stupidity allotment, I almost feel smarter.  ;)
Thanks Aslan!
Title: Re: Stupid Questions :o
Post by: magnamentis on January 24, 2017, 04:11:03 PM
+1

Would love to ask more questions, fear used up my stupidity allotment, I almost feel smarter.  ;)
Thanks Aslan!

don't worry, really smart people know at all times how "stupid" they are when they compare their own level of knowledge to the entire available knowledge and even more so when they include the yet unknown into their considerations. it's one thing that is distinguishing the smart from the stupid, the stupid think they're soo.... smart while the smart know how stupid they are LOL
Title: Re: Stupid Questions :o
Post by: budmantis on January 24, 2017, 04:40:31 PM
+1

Would love to ask more questions, fear used up my stupidity allotment, I almost feel smarter.  ;)
Thanks Aslan!

don't worry, really smart people know at all times how "stupid" they are when they compare their own level of knowledge to the entire available knowledge and even more so when they include the yet unknown into their considerations. it's one thing that is distinguishing the smart from the stupid, the stupid think they're soo.... smart while the smart know how stupid they are LOL

Well said, Magnamentis. We're always learning no matter how old we are or how educated.
Title: Re: Stupid Questions :o
Post by: magnamentis on January 24, 2017, 06:49:07 PM
+1

Would love to ask more questions, fear used up my stupidity allotment, I almost feel smarter.  ;)
Thanks Aslan!

don't worry, really smart people know at all times how "stupid" they are when they compare their own level of knowledge to the entire available knowledge and even more so when they include the yet unknown into their considerations. it's one thing that is distinguishing the smart from the stupid, the stupid think they're soo.... smart while the smart know how stupid they are LOL

Well said, Magnamentis. We're always learning no matter how old we are or how educated.

just because i love the topic so much, interestingly the more we know the more questions arise and  seems there to learn until we come to the point when we get kind of overwhelmed and start filtering passively instead of seeking specific knowledge. ( not exclusively, just a basic trend  and individually different of course )

similarly i started to distinguish between those who are proud of knowledge and those who humbly and simply enjoyi knowledge. a huge difference as to the level of ego involved, further it's a gift to be curious and intelligent, not an achievement, hence nothing to be proud of but something
that we can enjoy in case of being blessed :-)
Title: Re: Stupid Questions :o
Post by: sidd on January 24, 2017, 07:25:32 PM
Decades ago when i was in physics grad school, i had a professor named Bob Mills (physics aficionados might remember Yang-Mills theory.) For a man of prodigious intellect, he was suprisingly humble, and never worried about revealing his ignorance. He was fond of attending seminars in fields other than physics, and was fearless in asking the most elementary questions. Students loved this habit, for he would ask the ones they wanted to, but were shy about.

One of his favorite phrases was "Let me ask a naive question ..." Very often the question may have been naive but the subsequent discussion was better than the whole preceding seminar.

sidd
Title: Re: Stupid Questions :o
Post by: budmantis on January 24, 2017, 10:21:38 PM
Decades ago when i was in physics grad school, i had a professor named Bob Mills (physics aficionados might remember Yang-Mills theory.) For a man of prodigious intellect, he was suprisingly humble, and never worried about revealing his ignorance. He was fond of attending seminars in fields other than physics, and was fearless in asking the most elementary questions. Students loved this habit, for he would ask the ones they wanted to, but were shy about.

One of his favorite phrases was "Let me ask a naive question ..." Very often the question may have been naive but the subsequent discussion was better than the whole preceding seminar.

sidd

Humility is underrated, sounds like he was a man for all seasons.
Title: Re: Stupid Questions :o
Post by: Jim Williams on January 28, 2017, 06:32:16 PM
How come all the models and papers talk about a shutdown in the thermohaline circulation when the data we are watching this winter is the North Atlantic Drift flowing into the Arctic Ocean?

I guess I just know the right question to ask Google.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on January 28, 2017, 06:40:05 PM
How come all the models and papers talk about a shutdown in the thermohaline circulation when the data we are watching this winter is the North Atlantic Drift flowing into the Arctic Ocean?

I guess I just know the right question to ask Google.


I've been wondering the same thing.
Title: Re: Stupid Questions :o
Post by: Tigertown on January 28, 2017, 07:05:15 PM
Someone or someone's model thought the GIS would melt faster than the oceans would warm.
Title: Re: Stupid Questions :o
Post by: Jim Williams on January 28, 2017, 07:39:04 PM
Someone or someone's model thought the GIS would melt faster than the oceans would warm.

Hehehe.  I think you are right.

I know there's an alternate theory out there that might match what is happening better...but I don't know how to ask for current research on the subject which I might find more believable than the thermohaline shutdown.
Title: Re: Stupid Questions :o
Post by: Iceismylife on January 28, 2017, 11:45:32 PM
Someone or someone's model thought the GIS would melt faster than the oceans would warm.

Hehehe.  I think you are right.

I know there's an alternate theory out there that might match what is happening better...but I don't know how to ask for current research on the subject which I might find more believable than the thermohaline shutdown.
Jakobshaven hasn't kept speeding up like it was.  The fjord is now choked with bits and bergs. Zachariae just had the fjord in front of its calving face brake up for the first time in several years. And melt may be off a bit from expected.

Albedo may be a bigger player than thought.

My opinion for what it is worth is Antarctica will have an ice shelf collapse, then sea level will go up, then GIS will shed more ice in bergs, then the thermohaline circulation will shut down.
Title: Re: Stupid Questions :o
Post by: johnm33 on January 28, 2017, 11:46:42 PM
I used to believe that the NAD was the result of persistent winds blowing across the Atlantic, that view is changing it seems more likely that it's the residual of tidal movements in the north atlantic and as such more water means more current. Also with so much melt water coming out of the arctic and off of greenlands east coast the natural flows are now more nearly aligned with the tidal forces. One glimmer of hope is that perhaps these waters being churned and exposed to the north atlantic winter will begin to arrive in barents somewhat cooled, though there are slim signs so far.
(https://upload.wikimedia.org/wikipedia/commons/5/5e/M2_tidal_constituent.jpg)
Title: Re: Stupid Questions :o
Post by: Tealight on January 29, 2017, 01:44:08 AM
How come all the models and papers talk about a shutdown in the thermohaline circulation when the data we are watching this winter is the North Atlantic Drift flowing into the Arctic Ocean?

I guess I just know the right question to ask Google.

The thermohaline circulation in the North Atlantic is driven by cold salty water sinking to the bottom off the coast of Greenland. If the Atlantic warms then the water isn't dense enough to sink to the sea floor. Someone or his model concluded that this would completly stop the thermohaline circulation.

I think the circulation just shifts further north into the Barents Sea and beyond. The Arctic has the right topographical features for it. All cold salty water can sink into the Arctic Basin and exit through the deep Fram straight where it rejoins the current thermohaline circulation.
Title: Re: Stupid Questions :o
Post by: CognitiveBias on January 30, 2017, 12:22:36 AM
Jai,
  The nullschool view is certainly dramatic...  I've been tracking it as well for a while now.

I'm unclear how you get ~4C though.  I see light blue as 0 to -10C.  Anything over 0 I see as green.  Am I missing something?

https://earth.nullschool.net/#2017/02/03/1800Z/wind/surface/level/overlay=temp/orthographic=-92.96,92.34,1339/loc=-15.747,75.726


Also interesting is the heat and wind on the Fram side.  Export should be picking up.

Thanks!  CB
 
Title: Re: Stupid Questions :o
Post by: logicmanPatrick on January 30, 2017, 06:47:44 AM
How come all the models and papers talk about a shutdown in the thermohaline circulation when the data we are watching this winter is the North Atlantic Drift flowing into the Arctic Ocean?

I guess I just know the right question to ask Google.

The thermohaline circulation in the North Atlantic is driven by cold salty water sinking to the bottom off the coast of Greenland. If the Atlantic warms then the water isn't dense enough to sink to the sea floor. Someone or his model concluded that this would completly stop the thermohaline circulation.

I think the circulation just shifts further north into the Barents Sea and beyond. The Arctic has the right topographical features for it. All cold salty water can sink into the Arctic Basin and exit through the deep Fram straight where it rejoins the current thermohaline circulation.

Slowdown is highly likely.  Previously, the warm water would start to be cooled as soon as it passed under the marginal ice near Iceland.  Also, thick sea ice in process of rejecting salt would make the current saltier.  Year by year the trend is for the warm Atlantic water to penetrate further north, all the time being cooled less and mixing with less rejected saline. 

Ultimately the long-term trend to lower specific gravity must lead to a slower rate of descent, hence a slower thermohaline circulation.  This will carry heat from the tropics more slowly, hence more heat to travel south.  After a few years the polar see-saw kicks in and Antarctic glaciers begin to accelerate.

That's just my humble opinion and as such is open to critical assessment.
Title: Re: Stupid Questions :o
Post by: jdallen on January 30, 2017, 09:50:17 AM
Stupid question follow on...

What is the estimate for the total flow into and out of the Arctic basin, in KM3 of water?

The reason I ask is, salt purge out of freezing ice is only going to be a small fraction of the volume of ice melted (which is going to be less than 6000 or so KM3 a season).  If we presume 10% of that - or 600KM3/year, what fraction would that be of the total circulation?

Point I'm making here is, is the refreeze really what's driving the circulation?
Title: Re: Stupid Questions :o
Post by: Pmt111500 on January 30, 2017, 11:41:49 AM
Stupid question follow on...

What is the estimate for the total flow into and out of the Arctic basin, in KM3 of water?

<clip>

Point I'm making here is, is the refreeze really what's driving the circulation?

No numbers from me, but the latter point such a good one I thought to add in the expected snowfalls on open ocean during future polar nights.
Title: Re: Stupid Questions :o
Post by: DavidR on January 30, 2017, 12:27:56 PM
Stupid question follow on...

What is the estimate for the total flow into and out of the Arctic basin, in KM3 of water?

The reason I ask is, salt purge out of freezing ice is only going to be a small fraction of the volume of ice melted (which is going to be less than 6000 or so KM3 a season).  If we presume 10% of that - or 600KM3/year, what fraction would that be of the total circulation?

Point I'm making here is, is the refreeze really what's driving the circulation?

According to wikipedia total flow out of the Arctic is about 11 Sverdrups.

( A sverdrup) is equivalent to 1 million cubic metres per second (264,000,000 USgal/s). The entire global input of fresh water from rivers to the ocean is equal to about 1.2 sverdrup.

Therefore a Sverdrup is equivalent to 1/1000th of a Km^3. So  in a day the outflow is approx 8640 * 11 / 1000 Km^3. per day so about 95 Km^3 per day. The inflow from rivers would be at best 100th of this so the rest must come from the Atlantic and Pacific.

600Km^3 therfore amounts to  about 2% of the flow.
Title: Re: Stupid Questions :o
Post by: shmengie on February 02, 2017, 03:49:32 AM
Is this right, or am I just making this stuff up?

Quote
Since 2015, 80°North hasn't been below 245K(elvin)
In 1960, 80°North was rarely above 245K in Arctic winter

Over the last decade, the average temperature 80°North has shifted almost~10°K warmer during winter.

The extreme North climate has changed more drastically in the past decade than lower latitudes.

Artic multi-year sea ice is a thing of the past leaving only Greenland's snow/ice & pack surviving in the northern hemisphere.  After Greenland melts, Antarctica will be the last multi-year ice (MYI) on the planet.

After Antarctica, it may be centuries before MYI returns to the surface of the planet, barring a global volcanic, nuclear or astrological event cause a cooling period sooner.

Been eyeballing graphs, thats what the trends spell out to me.
Title: Re: Stupid Questions :o
Post by: bairgon on February 02, 2017, 02:16:13 PM
I have a heat budget question. This may be all complete rubbish but comes out of thinking about the after-effects of the GAC with many gaps in the ice freezing over, and therefore increasing the area graph. 

When ice melts, heat is absorbed to make the transition from solid to liquid (latent heat). Conversely, when ice is made, heat must be released. That's a strange way of looking at it, but the enthalpy of the system is constant.

So, assuming that the heat is released into the air as it seems to me that the air drives ice formation, what is the impact on air temperature? Some very rough calculations:

The heat of fusion for water is 334 joules per gram. There are 10^6 g in 1 m^3 of water so the heat of fusion for 1 m^3 of water is 334 x 10^6 joules or 0.334 x 10^6 kj.

Assume an open sea area of 10km x 10km in which of 0.25m thick forms. The volume of ice is 0.25 x 10^8 m^3. Therefore the total heat of fusion is 0.0835 x 10^14 kj, or 8.35 x 10^12 kj.

Assuming cold temps and taking some approximations, the density of air is 1.39 kg / m^3. The specific heat of air is defined in kj/kg K and is close enough to 1. That means that 1 kj will raise the temperature of 1 kg of air by 1 degrees K.

If we take a volume of air 100km x 100km x 100m thick (assuming it is blowing over the ice) then that is 10^12 m^3. The weight is 1.39 x 10^12 kg. Dividing the kj released from freezing the ice by that weight gives around 6 degrees K temperature rise.

Therefore it seems to me that the freezing of the open areas opened up by the GAC will have had some not insignificant effect on the air temperatures. This will reduce the FDDs by some factor.

I guess the effect on air temperature could be determined by correlating rises with polynyas refreezing. Probably going to be difficult to pick out the values.

So there appears to be a triple impact of the GAC:
- air temperature increased due to new ice formation, decreasing FDDs for other ice
- ice export to warmer ocean areas
- thin ice formed is less rigid and more prone to eventual melting, breakup and warming via insolation in the summer

Title: Re: Stupid Questions :o
Post by: Tigertown on February 02, 2017, 03:04:34 PM
@bairgon
No problem bairgon, the heat can just escape out into space and not bother anything at all.
OOPS! It can't escape that easy anymore, can it? Now it and every other source, like heat from upwelling warm water, is a problem. Upwelling hurt ice before, but now it can't escape even in open water areas  as easily. It's a heat trap extraordinaire.
Title: Re: Stupid Questions :o
Post by: oren on February 03, 2017, 02:27:02 PM
Is this right, or am I just making this stuff up?

Quote
Since 2015, 80°North hasn't been below 245K(elvin)
In 1960, 80°North was rarely above 245K in Arctic winter

Over the last decade, the average temperature 80°North has shifted almost~10°K warmer during winter.

The extreme North climate has changed more drastically in the past decade than lower latitudes.

Artic multi-year sea ice is a thing of the past leaving only Greenland's snow/ice & pack surviving in the northern hemisphere.  After Greenland melts, Antarctica will be the last multi-year ice (MYI) on the planet.

After Antarctica, it may be centuries before MYI returns to the surface of the planet, barring a global volcanic, nuclear or astrological event cause a cooling period sooner.

Been eyeballing graphs, thats what the trends spell out to me.
Shmengie, referring to some of your statements: "Arctic multi-year sea ice is a thing of the past" - not true. There is still 3, 4, and 5-year sea ice in the Arctic, just much less of it than used to be. Even after a virtually ice-free September there will still be multi-year sea ice, unless there was a complete melt-down of every last ice floe. This will happen at some point, but not necessarily in the very near future.
In addition, The ice on Greenland and Antarctica is not referred to as multi-year ice / MYI (though linguistically it might be correct). Not sure the correct terminology - Ice Sheets and Glaciers? Glaciated ice?
Finally, the Antarctic ice sheet is expect to survive in some form at least for centuries to millenia (and more).
Title: Re: Stupid Questions :o
Post by: Graham P Davis on February 04, 2017, 11:09:10 AM
How come all the models and papers talk about a shutdown in the thermohaline circulation when the data we are watching this winter is the North Atlantic Drift flowing into the Arctic Ocean?

I guess I just know the right question to ask Google.

According to something I read almost fifty years ago, the sudden shutdowns of the NAD were associated with the current circulation of the North Atlantic being bimodal. What happened in the alternate mode to the present situation was that the NAD no longer spun off from the Gulf Stream but was replaced by an extension of the Labrador Current. I assume that this change meant that the volume of water in the NAD remained unchanged but was somewhat colder and less saline.

According to what I read then, the cause of the sudden switched in the circulation was unknown. The best guess was that it was due to a slowing of the Gulf Stream as a response to a weakening of the subtropical high. When I heard about the shutdown in the thermohaline circulation, I assumed this was the answer but just recently I have wondered whether it has more to do with salinity changes in the surface waters with a lowering of salinity of the Labrador current causing it to stop sinking below the Gulf Stream and flow over the NAD instead. The warm NAD would then sink to replace the submarine extension of the Labrador Current.
Title: Re: Stupid Questions :o
Post by: Neven on February 04, 2017, 02:30:01 PM
Welcome, Graham. Your profile has been released.
Title: Re: Stupid Questions :o
Post by: shmengie on February 04, 2017, 04:07:11 PM
Shmengie, referring to some of your statements: "Arctic multi-year sea ice is a thing of the past" - not true.

Thanks oren.  I was scratching my head about how old some of the MYI in the Artic was.  Thought there was some remaining, but for the most part, its waning toward being gone.

Not been to the Arctic. A set of before & after pictures of glacial landscapes, formed the impression of MYI sea ice gone, in my head.  Been reluctant to post a link to these pictures here, because they're not entirely relevant, but stunning. Couldn't find them on weather.com, where I first saw them.  Don't know why... This site presents them better, tho.

Stunning before & after photos:
http://www.snowaddiction.org/2014/06/photos-from-alaska-then-and-now-this-is-a-get-ready-to-be-shocked-when-you-see-what-it-looks-like-now.html (http://www.snowaddiction.org/2014/06/photos-from-alaska-then-and-now-this-is-a-get-ready-to-be-shocked-when-you-see-what-it-looks-like-now.html)
Title: Re: Stupid Questions :o
Post by: Tigertown on February 04, 2017, 04:24:12 PM
Some of the individuals at the weather channel have strong opinions about changes in the climate and the Arctic, but it is kind of like someone is holding them back from talking about it very much. This is reflected in their website at weather.com .

It is a shame that they don't cover the Arctic more, on both media outlets, as they have such a large following.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on February 05, 2017, 05:38:13 AM
Where are the dmi +80 numbers for 2016? I downloaded the two pieces and the other one ends at 2015/12/31 and the current starts from 2017/1/1. This is no biggie though, doing historical stats ( if i get to it) won't depend on one recent year, only asking for the sake of completeness. Maybe i hit the dataset before the yearly update, so should check it myself too.
Title: Re: Stupid Questions :o
Post by: Jim Williams on February 10, 2017, 06:20:29 PM
is this really true?  I'm having a bit of trouble believing that the distance between freezing and boiling in pure water at standard pressure has any relationship to the percentage change in energy at arbitrary temperatures.

What ktnonine said is correct, but it has nothing to do with the freezing/boiling temperature of water. Converted to Celsius, he just said "-172.15°C is 1% more energy than -173.15°C". It's a bit neater in Kelvin  ;)

The only bit that's incorrect is that it should be 101K, not 101°K, as Kelvin is an absolute scale and therefore not in degrees (c.f. degrees in an angle vs radians)

I don't get it, and if this is true then I need a very careful explanation of the units of measurement and physics such that a 1 degree K (or C) equals ONE PERCENT.
Title: Re: Stupid Questions :o
Post by: Seumas on February 10, 2017, 06:26:38 PM
I don't get it, and if this is true then I need a very careful explanation of the units of measurement and physics such that a 1 degree K (or C) equals ONE PERCENT.
Ah, right, I think I see what you don't get.

It doesn't make any difference how large a unit Kelvin is. Let's imagine I create a new absolute temperature scale. We can call it Seulcius! And 1S == 2°C (== 2K).

Now, the difference between freezing and boiling water is 50S. But I can still say, "101S is 1% more energy than 100S". Which, in Kelvin, is like saying, "202K is 1% more energy than 200K".

There is in fact an absolute scale that uses Farenheit spaced units, called the Rankine scale. And 101R is 1% more energy than 100R.

If that hasn't made it clear, think of it as distance. If you have a standard length Stride, then 101 Strides is 1% more than 100 Strides, whether the Stride is 10cm or 20 miles.
Title: Re: Stupid Questions :o
Post by: ktonine on February 10, 2017, 06:31:58 PM
The only bit that's incorrect is that it should be 101K, not 101°K, as Kelvin is an absolute scale and therefore not in degrees (c.f. degrees in an angle vs radians)

Aaaaack!  Yes, I am chagrined at the mistake.

Physicist Matt Strassler had a nice post on energy and temperature back in 2014  - Happy (Chilly) New Year (https://profmattstrassler.com/2014/01/07/happy-chilly-new-year/)

Jim, go read the Matt Strassler link above.  It's a nice physical explanation that a layperson can understand by a physicist.

Title: Re: Stupid Questions :o
Post by: Jim Williams on February 10, 2017, 07:05:50 PM
If that hasn't made it clear, think of it as distance. If you have a standard length Stride, then 101 Strides is 1% more than 100 Strides, whether the Stride is 10cm or 20 miles.
No....one stride (two steps, step one left and step one right) is infinitely more than 0 strides, and and it is an indeterminate amount more than one step -- most people step more with one foot than another.  101 strides is merely one stride more than 100 strides -- it is no percents more.  (Figures don't lie, but liars figure.)
Title: Re: Stupid Questions :o
Post by: Seumas on February 10, 2017, 07:28:13 PM
101 strides is merely one stride more than 100 strides -- it is no percents more.
You haven't put a smiley in there, so I can't tell if you're joking or genuinely confused.

If the standard Stride is 10 cm, then 100 Strides is 1000 cm and 101 Strides is 1010 cm, which is 1% greater.

If the standard Stride is 20 miles, then 100 Strides is 2000 miles and 101 Strides is 2020 miles, which is 1% greater.
Title: Re: Stupid Questions :o
Post by: Jim Williams on February 10, 2017, 07:33:37 PM
101 strides is merely one stride more than 100 strides -- it is no percents more.
You haven't put a smiley in there, so I can't tell if you're joking or genuinely confused.

If the standard Stride is 10 cm, then 100 Strides is 1000 cm and 101 Strides is 1010 cm, which is 1% greater.

If the standard Stride is 20 miles, then 100 Strides is 2000 miles and 101 Strides is 2020 miles, which is 1% greater.
Then this is purely a case of liars figure.  1% of which measure?  The previous stride or the current stride?
Title: Re: Stupid Questions :o
Post by: crandles on February 10, 2017, 07:51:43 PM

Then this is purely a case of liars figure.  1% of which measure?  The previous stride or the current stride?

I'm lost. Do you accept that 21K is 5% more than 20K? Or are you complaining that this is 5% and not the same 1%?
Title: Re: Stupid Questions :o
Post by: Jim Williams on February 10, 2017, 09:13:25 PM

Then this is purely a case of liars figure.  1% of which measure?  The previous stride or the current stride?

I'm lost. Do you accept that 21K is 5% more than 20K? Or are you complaining that this is 5% and not the same 1%?
No....I do not accept that.  If you take the 21K as the basis than it is one thing, but if you take the 20K as the basis it is another.  Liars figure.  You have to specify what you are talking about extremely precisely or percent is meaningless.  Actually....percent is basically meaningless to begin with unless you are talking about dice odds.

Title: Re: Stupid Questions :o
Post by: Seumas on February 10, 2017, 09:19:10 PM
No....I do not accept that.
Then I'm afraid the problem is simply that you don't understand percentages. I suggest you look at the Khan Academy videos which explain how percentages work.

Quote
Actually....percent is basically meaningless to begin with unless you are talking about dice odds.
It's really not. It means "per hundred". An increase of 1% means you multiply the figure you are talking about by 1.01 because you are increasing it by one part in a hundred. That's it. There is literally no-one here confused about what the percentage increase refers to, except you.
Title: Re: Stupid Questions :o
Post by: Jim Williams on February 10, 2017, 09:23:49 PM
No....I do not accept that.
Then I'm afraid the problem is simply that you don't understand percentages. I suggest you look at the Khan Academy videos which explain how percentages work.

Quote
Actually....percent is basically meaningless to begin with unless you are talking about dice odds.
It's really not. It means "per hundred". An increase of 1% means you multiply the figure you are talking about by 1.01 because you are increasing it by one part in a hundred. That's it. There is literally no-one here confused about what the percentage increase refers to, except you.

You must not have bothered to read what I wrote.  Go away.
Title: Re: Stupid Questions :o
Post by: ktonine on February 10, 2017, 09:29:31 PM
You must not have bothered to read what I wrote.  Go away.

???

Percent and percent error have long been used both colloquially and scientifically.  Obviously correctly defining the dividend and divisor makes a difference -- but that's true in *any* similar mathematical statement. 

Like Seumas, I at first assumed you were joking.  Now you just seem a bit off.
Title: Re: Stupid Questions :o
Post by: dj on February 10, 2017, 09:33:28 PM
Wouldn't the Boltzmann constant be applicable here?  1.380655·10-23 J/K.
Since it is linear in regards to energy and temperature the percent increase of energy is dependent upon the starting temperature (a measure of the energy in the system).

The change in energy is proportional to the change in Kelvin, but the percent change in energy per degree Kelvin is not.  I think this is where the disagreement arises. 

In regards to it being tied to something, it is - the triple point of water, which can vary depending upon the isotopic composition of the water.  There are attempts to minimize the uncertainty in the measurement of the Boltzmann constant.  Once that is achieved it essentially will not be tied to the properties of water.  Not sure that has been achieved as of yet.

The kelvin: The Boltzmann Project
https://www.ptb.de/cms/en/research-development/research-on-the-new-si/ptb-experiment/the-kelvin-the-boltzmann-project.html (https://www.ptb.de/cms/en/research-development/research-on-the-new-si/ptb-experiment/the-kelvin-the-boltzmann-project.html)
Title: Re: Stupid Questions :o
Post by: Seumas on February 10, 2017, 09:53:24 PM
You must not have bothered to read what I wrote.  Go away.

I think I'll assume you're posting drunk and will make more sense tomorrow. Have a good evening.
Title: Re: Stupid Questions :o
Post by: Neven on February 10, 2017, 10:19:00 PM
Wouldn't the Boltzmann constant be applicable here?  1.380655·10-23 J/K.
Since it is linear in regards to energy and temperature the percent increase of energy is dependent upon the starting temperature.

In regards to it being tied to something, it is - the triple point of water, which can vary depending upon the isotopic composition of the water.  There are attempts to minimize the uncertainty in the measurement of the Boltzmann constant.  Once that is achieved it essentially will not be tied to the properties of water.  Not sure that has been achieved as of yet.

The kelvin: The Boltzmann Project
https://www.ptb.de/cms/en/research-development/research-on-the-new-si/ptb-experiment/the-kelvin-the-boltzmann-project.html (https://www.ptb.de/cms/en/research-development/research-on-the-new-si/ptb-experiment/the-kelvin-the-boltzmann-project.html)

Welcome, dj, your profile has been released.
Title: Re: Stupid Questions :o
Post by: dj on February 10, 2017, 10:24:13 PM
Wouldn't the Boltzmann constant be applicable here?  1.380655·10-23 J/K.
Since it is linear in regards to energy and temperature the percent increase of energy is dependent upon the starting temperature.

In regards to it being tied to something, it is - the triple point of water, which can vary depending upon the isotopic composition of the water.  There are attempts to minimize the uncertainty in the measurement of the Boltzmann constant.  Once that is achieved it essentially will not be tied to the properties of water.  Not sure that has been achieved as of yet.

The kelvin: The Boltzmann Project
https://www.ptb.de/cms/en/research-development/research-on-the-new-si/ptb-experiment/the-kelvin-the-boltzmann-project.html (https://www.ptb.de/cms/en/research-development/research-on-the-new-si/ptb-experiment/the-kelvin-the-boltzmann-project.html)

Welcome, dj, your profile has been released.

Thank you.
Title: Re: Stupid Questions :o
Post by: sidd on February 10, 2017, 10:45:56 PM
There is a relation between Temperature and Energy, but it is not necessarily linear ...

For a simple example, consider the change in the internal energy U of 1 gm of water as it is cooled successively from a) 1.5C to 0.5C b) 0.5C to -0.5C

Step a) is a change in U of 4.2 calorie.
Step b) is a change of 84.2 calorie
 
both steps involve a 1C change in temperature, but quite different amounts of energy

sidd
Title: Re: Stupid Questions :o
Post by: epiphyte on February 10, 2017, 10:51:05 PM
The only bit that's incorrect is that it should be 101K, not 101°K, as Kelvin is an absolute scale and therefore not in degrees (c.f. degrees in an angle vs radians)

Aaaaack!  Yes, I am chagrined at the mistake.

Physicist Matt Strassler had a nice post on energy and temperature back in 2014  - Happy (Chilly) New Year (https://profmattstrassler.com/2014/01/07/happy-chilly-new-year/)

Jim, go read the Matt Strassler link above.  It's a nice physical explanation that a layperson can understand by a physicist.

Now I'm going to add confusion to the issue by mentioning that a slightly negative absolute temperature is in fact possible...

viz:  https://phys.org/news/2013-01-atoms-negative-absolute-temperature-hottest.html (https://phys.org/news/2013-01-atoms-negative-absolute-temperature-hottest.html)

... it spoils the fun somewhat though to add that this is an artifact of the definition of temperature; a negative value exists if the pressure goes down as you add energy - Paradoxically this can be made to happen happen by creating a system in which an atomic gas is very hot and still being heated but the individual atoms have an upper limit to the amount of kinetic energy they can possess (as in the above experiment, which trapped them in a lattice of laser interference patterns).

For those wondering how under the above circumstances adding further energy reduces the pressure, I'm kind of fuzzy on that myself - but my hand-waving understanding of it is that there's a normally insignificant amount of quantum tunneling going on, which suddenly becomes more significant if kinetic energy is maxed-out.

Title: Re: Stupid Questions :o
Post by: Jim Williams on February 10, 2017, 10:55:04 PM
There is a relation between Temperature and Energy, but it is not necessarily linear ...

For a simple example, consider the change in the internal energy U of 1 gm of water as it is cooled successively from a) 1.5C to 0.5C b) 0.5C to -0.5C

Step a) is a change in U of 4.2 calorie.
Step b) is a change of 84.2 calorie
 
both steps involve a 1C change in temperature, but quite different amounts of energy

sidd

Thank you.  I think I will state the original question over again even though you you have answered it...just so the rest will understand.

The statement I was questioning was that the change from 100 degrees K to 101 degrees K entailed 1% change in energy.  I could not understand how that could be true...and as you point out, it was not.  In fact, you have pointed out that the statement was meaningless and irrelevant.

Title: Re: Stupid Questions :o
Post by: dj on February 10, 2017, 11:11:58 PM
There is a relation between Temperature and Energy, but it is not necessarily linear ...

For a simple example, consider the change in the internal energy U of 1 gm of water as it is cooled successively from a) 1.5C to 0.5C b) 0.5C to -0.5C

Step a) is a change in U of 4.2 calorie.
Step b) is a change of 84.2 calorie
 
both steps involve a 1C change in temperature, but quite different amounts of energy

sidd

Because you are undergoing a phase change.  That is a poor example as it relies upon the heat capacity of water (for example A) and the heat of fusion of water (example B).  See the Boltzmann constant above.

Edit: Corrected spelling
Title: Re: Stupid Questions :o
Post by: dj on February 10, 2017, 11:17:52 PM
Quote
Thank you.  I think I will state the original question over again even though you you have answered it...just so the rest will understand.

The statement I was questioning was that the change from 100 degrees K to 101 degrees K entailed 1% change in energy.  I could not understand how that could be true...and as you point out, it was not.  In fact, you have pointed out that the statement was meaningless and irrelevant.

The Boltzmann constant is 1.38064852 × 10-23 J/K. 
The percent change in temperature is equal to the percent change in energy.
The percent change in energy per degree Kelvin would depend upon the starting temperature.

I think this is the source of your confusion.
Title: Re: Stupid Questions :o
Post by: dj on February 10, 2017, 11:35:54 PM
There is a relation between Temperature and Energy, but it is not necessarily linear ...

For a simple example, consider the change in the internal energy U of 1 gm of water as it is cooled successively from a) 1.5C to 0.5C b) 0.5C to -0.5C

Step a) is a change in U of 4.2 calorie.
Step b) is a change of 84.2 calorie
 
both steps involve a 1C change in temperature, but quite different amounts of energy

sidd

Thank you.  I think I will state the original question over again even though you you have answered it...just so the rest will understand.

The statement I was questioning was that the change from 100 degrees K to 101 degrees K entailed 1% change in energy.  I could not understand how that could be true...and as you point out, it was not.  In fact, you have pointed out that the statement was meaningless and irrelevant.

To further elaborate. 
Temperature is simply a measure of the amount of energy present in the molecules of whatever you are measuring.

Temperature as measured in Kelvin is set at the triple point of water.  And is defined such that 0 K is where there is no energy in the molecule, it is not moving or vibrating because it has no energy associated with it.

The Boltzmann constant describes the linear relationship between the amount of energy represented by Kelvin units, which is 1.38064852 × 10-23 J/K.

Because this is a linear relationship, the percent change in Kelvin equals the percent change in energy.  The percent change of energy per degree Kelvin does change.

I hope this helps.
Title: Re: Stupid Questions :o
Post by: DrTskoul on February 11, 2017, 12:04:34 AM
There is a relation between Temperature and Energy, but it is not necessarily linear ...

For a simple example, consider the change in the internal energy U of 1 gm of water as it is cooled successively from a) 1.5C to 0.5C b) 0.5C to -0.5C

Step a) is a change in U of 4.2 calorie.
Step b) is a change of 84.2 calorie
 
both steps involve a 1C change in temperature, but quite different amounts of energy

sidd

Thank you.  I think I will state the original question over again even though you you have answered it...just so the rest will understand.

The statement I was questioning was that the change from 100 degrees K to 101 degrees K entailed 1% change in energy.  I could not understand how that could be true...and as you point out, it was not.  In fact, you have pointed out that the statement was meaningless and irrelevant.

To further elaborate. 
Temperature is simply a measure of the amount of energy present in the molecules of whatever you are measuring.

Temperature as measured in Kelvin is set at the triple point of water.  And is defined such that 0 K is where there is no energy in the molecule, it is not moving or vibrating because it has no energy associated with it.

The Boltzmann constant describes the linear relationship between the amount of energy represented by Kelvin units, which is 1.38064852 × 10-23 J/K.

Because this is a linear relationship, the percent change in Kelvin equals the percent change in energy.  The percent change of energy per degree Kelvin does change.

I hope this helps.

Except when we are talking about the internal energy of a substance with a phase change as given with examples above.
Title: Re: Stupid Questions :o
Post by: dj on February 11, 2017, 12:11:12 AM
True, but that was not the source of confusion that Jim was having previously. He was having trouble understanding why the percent change of energy is equal to the percent change in temperature as measured in Kelvins.

As I pointed out previously, the example given is poor one because it does include a phase change and has nothing to do with the relationship between Kelvin and Energy.
Title: Re: Stupid Questions :o
Post by: DrTskoul on February 11, 2017, 12:14:09 AM
True, but that was not the source of confusion that Jim was having previously. He was having trouble understanding why the percent change of energy is equal to the percent change in temperature as measured in Kelvins.

As I pointed out previously, the example given is poor one because it does include a phase change and has nothing to do with the relationship between Kelvin and Energy.

Late in the discussion :)

Thanks!
Title: Re: Stupid Questions :o
Post by: Hyperion on February 11, 2017, 12:04:31 PM
Stupid question follow on...

What is the estimate for the total flow into and out of the Arctic basin, in KM3 of water?

The reason I ask is, salt purge out of freezing ice is only going to be a small fraction of the volume of ice melted (which is going to be less than 6000 or so KM3 a season).  If we presume 10% of that - or 600KM3/year, what fraction would that be of the total circulation?

Point I'm making here is, is the refreeze really what's driving the circulation?

According to wikipedia total flow out of the Arctic is about 11 Sverdrups.

( A sverdrup) is equivalent to 1 million cubic metres per second (264,000,000 USgal/s). The entire global input of fresh water from rivers to the ocean is equal to about 1.2 sverdrup.

Therefore a Sverdrup is equivalent to 1/1000th of a Km^3. So  in a day the outflow is approx 8640 * 11 / 1000 Km^3. per day so about 95 Km^3 per day. The inflow from rivers would be at best 100th of this so the rest must come from the Atlantic and Pacific.

600Km^3 therfore amounts to  about 2% of the flow.

Does anyone get any devious notions from numbers like this or is it just me.  ;)

specific heat capacity of water = 4.2 kj/kg/K
~42 000 000 000 000 kJ per day for 1% of flow out of arctic ocean (~100km^3) at 10k difference
= 486 000 000 kw = 486 000 megawatts = 486 gigawatts
world = 5 terawatts = 5million megawatts
therefore 10% of flow is equal to world electricity consumption
Irminger Current 11- 27 sverdrup = 11m-27m cubic m per sec.

Wouldn't it be nice to heat the greenland low salinity meltpool with gulfstream waters so it can radiate heat away, and not cause these cyclone canons? And thereby cool the Salty hot stuff to preserve overturning, but keep it south of the faroes- iceland ridge so it dinae get up north where its truble?.  :o  8)  ???
Anyone heard of heatpipes?
Title: Re: Stupid Questions :o
Post by: Neven on February 11, 2017, 12:06:49 PM
Welcome, Hyperion, your profile has been released.
Title: Re: Stupid Questions :o
Post by: Jim Williams on February 11, 2017, 03:19:10 PM
There is a relation between Temperature and Energy, but it is not necessarily linear ...

For a simple example, consider the change in the internal energy U of 1 gm of water as it is cooled successively from a) 1.5C to 0.5C b) 0.5C to -0.5C

Step a) is a change in U of 4.2 calorie.
Step b) is a change of 84.2 calorie
 
both steps involve a 1C change in temperature, but quite different amounts of energy

sidd

Thank you.  I think I will state the original question over again even though you you have answered it...just so the rest will understand.

The statement I was questioning was that the change from 100 degrees K to 101 degrees K entailed 1% change in energy.  I could not understand how that could be true...and as you point out, it was not.  In fact, you have pointed out that the statement was meaningless and irrelevant.

To further elaborate. 
Temperature is simply a measure of the amount of energy present in the molecules of whatever you are measuring.

Temperature as measured in Kelvin is set at the triple point of water.  And is defined such that 0 K is where there is no energy in the molecule, it is not moving or vibrating because it has no energy associated with it.

The Boltzmann constant describes the linear relationship between the amount of energy represented by Kelvin units, which is 1.38064852 × 10-23 J/K.

Because this is a linear relationship, the percent change in Kelvin equals the percent change in energy.  The percent change of energy per degree Kelvin does change.

I hope this helps.
I think I follow this, though I would like the see the dimensions spelled out -- especially the dimensions for temperature.  Am I correct that 100K to 101KM is an extremely special case, and that a 101K to 102K change would not yield a 1% change in energy?  Or is it the case that a 100K to 101K and a 101K to 102K change would cause the same percent, but not 1%?  (I don't think it is the second...)
Title: Re: Stupid Questions :o
Post by: oren on February 11, 2017, 03:42:32 PM
For anyone who has read the Matt Strassler link mentioned above, I think the whole thing is quite clear:
The ratio of temperatures (measured in Kelvin) is the ratio of kinetic energy of the molecules. From 300k to 330k means 10% more kinetic energy.
So: 1K means 1% only if you happen to be at 100k.
And: a phase change means the molecules gain or lose chemical bond energy, as long as temperature doesn't change that means their kinetic energy (and therefore motion speed) is the same.

It seems there have been some inaccurate statements in some of the posts above, but as far as I can tell this gives you the correct bottom line. (Until someone corrects me...)
Title: Re: Stupid Questions :o
Post by: DrTskoul on February 11, 2017, 04:01:18 PM
The internal energy of an ideal gas is proportional to its mass (number of moles) N and to its temperature T

 U = c N T,. C = heat capacity. Similar laws apply for diatomic, polyatomic gases etc.
Title: Re: Stupid Questions :o
Post by: longwalks1 on February 11, 2017, 04:45:48 PM
Lots of interesting stuff.  I did not post  in freezing because it was way off topic.  Working a lot of hours.  But going back to the catalyst of this post, quote unquote, technically minded writers adding or subtracting 32 when they should only be multiplying for temperature differentials. 

I have no idea how to stop that all too common error. I have seen it all too many times, and I do not recall retractions. I would guess that it is singular to U.S. citizens trying to convert from the original Celsius.  That might also explain the lack of retractions for that mistake from that subset.  If Rep. Charles Grassley (later Senator and Finance Chair) had not basically singularly stopped the metric system in the US, we would not be having this discussion. 

I was going to do a silly question of at what point does Kelvin and Fahrenheit intersect because I was too lazy to do the math but
  http://www.answers.com/Q/At_what_temperature_are_kelvin_and_fahrenheit_the_same (http://www.answers.com/Q/At_what_temperature_are_kelvin_and_fahrenheit_the_same)   does.  574.5875

Title: Re: Stupid Questions :o
Post by: dj on February 11, 2017, 04:54:18 PM
The Boltzmann constant is 1.38064852 × 10-23 J/K

In dimensions: K = Joules = W*s = N*m = (kg*m2)/s2

Example
1 K = 1.3806485 ×10-23 Joules.
2 K = 2.7612970 x10-23 Joules.

change in K: 2 K - 1 K = 1 K
change in Joules: 1.3806485 x 10-23 Joules
% change K = 100%
% change in Joules = 100%

Example
100 K = 138.06485 x10-23 Joules.
101 K= 139.4454985 x10-23 Joules.

change in K: 1 K
change in Joules: 1.3806485 x 10-23 Joules
% change in K: 1%
% change in Joules: 1%

The % change of energy per 1 Kelvin changes.  The % change of energy = % change in Kelvin.
Title: Re: Stupid Questions :o
Post by: Tor Bejnar on February 11, 2017, 05:35:52 PM
1% of 100 is, "magically" 1, so a 1% increase yields 101.  In a sense, this is a "special case".
1% of 101 is 1.01.  [Simply divide 101 by 100 - that is what the "0/0" symbol means - "percent" = "per-cent" = "for each 100" or "divided by 100"]  So a 1% increase from 101 is 102.01.*

"At what temperature is there a 1% energy increase from 0oF (https://en.wikipedia.org/wiki/Fahrenheit) [~-17.77oC]?" is a dangerous question.  "In the real world", the temperature must be converted to an 'absolute' scale like Kelvin, so 0oF ~ 255.37 K.  1% of 255.37 is ~2.55; a 1% increase yields 257.92K or, converted (http://www.onlineconversion.com/temperature.htm), -15.23oC or ~4.59oF.

From the MathNotations blog (http://mathnotations.blogspot.com/2008/02/temperature-changed-from-5-to-5-degrees.html):
Quote
"Your arithmetic is correct but your result is arbitrary. When expressing a temperature change as a percentage, one must use a temperature scale whose zero point is the temperature of absolute zero, and then use that selected scale consistently. The Kelvin scale is such a temperature scale. All other temperature systems, like Fahrenheit and Celsius, have arbitrary "zero points," and calculations of percent temperature change using those scales will give arbitrary results.

In the example you provided [edit by Tor: not related to my question above], on the Fahrenheit scale the temperature rise is 100 percent (from 50(degrees) to 100(degrees) F.), but that same change on the Celsius scale is 280 percent (from 10 to 38 C.). Using the Kelvin scale, whose zero point is absolute zero (-460(degrees) F., -273(degrees) C.), the rise is actually 10 percent, from 283(degrees) to 311(degrees) K."
----------
Tom Skilling is chief meteorologist at WGN-TV.

___
* - At the end of such sentences, I appreciate the European practice of using commas for decimal points!
Title: Re: Stupid Questions :o
Post by: Jim Williams on February 11, 2017, 05:43:53 PM
The Boltzmann constant is 1.38064852 × 10-23 J/K

In dimensions: K = Joules = W*s = N*m = (kg*m2)/s2

Example
1 K = 1.3806485 ×10-23 Joules.
2 K = 2.7612970 x10-23 Joules.

change in K: 2 K - 1 K = 1 K
change in Joules: 1.3806485 x 10-23 Joules
% change K = 100%
% change in Joules = 100%

Example
100 K = 138.06485 x10-23 Joules.
101 K= 139.4454985 x10-23 Joules.

change in K: 1 K
change in Joules: 1.3806485 x 10-23 Joules
% change in K: 1%
% change in Joules: 1%

The % change of energy per 1 Kelvin changes.  The % change of energy = % change in Kelvin.

The lightbulb dawns!

Since they are all in the same dimensions we don't want to talk in either Kelvin or Celsius.  We want to talk in Joules -- or rather Peta-joules (or something).
Title: Re: Stupid Questions :o
Post by: dj on February 11, 2017, 05:55:18 PM
Well that is what temperature scales, like Kelvin, does. 
However, it provides easier units to be able to do the math.

1 K = 0.00000000000000000000000138 Joules. = 1.38 x 10-23 Joules

The math is a bit easier using the Kelvin units ;)
Title: Re: Stupid Questions :o
Post by: sidd on February 11, 2017, 05:56:06 PM
The Boltzmann constant is more appropriate in discussions of ideal gases. In other cases, even those involving no phase change, say the internal energy of a crystal at low temperatures which goes as T^4 , temperature changes correspond to very nonlinear energy changes. Each increment of temperature gives nonlinear change in internal energy of a crystal. If the internal energy of a crystal at T=1K is U1, and that at 2K is U2, then the ratio U2/U1 is 2^4=16  even absent any phase change.

A deeper context for Boltzmann's constant than the ideal gas laws appears in the relationship of entropy S to number of microstates W in the formula S=k*ln(W)

Coupled with the thermodynamic definition of entropy, dS = integral(dQ/T) , one immediately sees the fundamental relation between entropy, internal states and information theory. I much prefer this as the defining relation for Boltzmann's constant, but others may differ.
 
sidd
Title: Re: Stupid Questions :o
Post by: Jim Williams on February 11, 2017, 06:05:30 PM
Well that is what temperature scales, like Kelvin, does. 
However, it provides easier units to be able to do the math.

1 K = 0.00000000000000000000000138 Joules. = 1.38 x 10-23 Joules

The math is a bit easier using the Kelvin units ;)

Wrong Math.  The interesting Stuff is in Watts and the like.
Title: Re: Stupid Questions :o
Post by: dj on February 11, 2017, 06:54:11 PM
The Boltzmann constant is more appropriate in discussions of ideal gases. In other cases, even those involving no phase change, say the internal energy of a crystal at low temperatures which goes as T^4 , temperature changes correspond to very nonlinear energy changes. Each increment of temperature gives nonlinear change in internal energy of a crystal. If the internal energy of a crystal at T=1K is U1, and that at 2K is U2, then the ratio U2/U1 is 2^4=16  even absent any phase change.

A deeper context for Boltzmann's constant than the ideal gas laws appears in the relationship of entropy S to number of microstates W in the formula S=k*ln(W)

Coupled with the thermodynamic definition of entropy, dS = integral(dQ/T) , one immediately sees the fundamental relation between entropy, internal states and information theory. I much prefer this as the defining relation for Boltzmann's constant, but others may differ.
 
sidd

Now you are confusing the Boltzmann constant (the measured internal kinetic energy) with the thermodynamic transfer of energy from a "black body" to its surroundings. 

This is covered by the Stefan-Boltzmann constant:
σ = 5.670367(13)×10−8 W⋅m−2⋅K−4

In which the Boltzmann constant (the internal kinetic energy of the crystal) is part of the equation determining the Stefan-Boltzmann constant.


where:

(https://wikimedia.org/api/rest_v1/media/math/render/svg/18a6b4ceda8340dba9a77ead245993abd9513c04)


kB is the Boltzmann constant;
h is the Planck constant;
ħ is the reduced Planck constant;
c is the speed of light in vacuum.
Wikipedia  [url=https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant] (http://Wikipedia  [url=https://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant)

Edit: corrected my statement as per what is being measured internally (thanks Dundee).

Title: Re: Stupid Questions :o
Post by: dj on February 11, 2017, 07:01:05 PM
Well that is what temperature scales, like Kelvin, does. 
However, it provides easier units to be able to do the math.

1 K = 0.00000000000000000000000138 Joules. = 1.38 x 10-23 Joules

The math is a bit easier using the Kelvin units ;)

Wrong Math.  The interesting Stuff is in Watts and the like.

The only wrong math is when something does not add up ;)

Kelvin is simply a measure of how many Watts there are at any given moment (s) = W*s.
Title: Re: Stupid Questions :o
Post by: Dundee on February 11, 2017, 08:20:23 PM
OK, I gotta wade into this morass . . .

Temperature very simply is a measure of hot and cold. Thermal energy flows from hot to cold, so temperature is a convenient way to track this. If you get much beyond this, it isn't simple any more.

The precise relation between temperature and energy implied from the Boltzmann constant applies to ideal gasses. Among other things, ideal gas molecules do not take up physical space and do not interact at a distance. At low pressures and high temperatures, many gasses act very like ideal gasses.

Back to the Arctic. At low temperatures, all gasses act less and less 'ideal'. And water vapor in particular (with strong intermolecular forces) is a particularly non-ideal gas.

The relation between temperature and energy in an engineering sense (with real materials) is defined as heat capacity. In an ideal gas, this is a constant, in real materials, it varies with temperature. Ice (and water vapor) has a heat capacity very roughly one-half that of liquid water. Changing one unit mass of water by one unit of temperature will change the temperature of two unit mass of ice or water vapor by the same magnitude of temperature, or twice the temperature difference in the same mass.

When matter freezes or vaporizes, energy is involved in the state change beyond that which changes temperature. In the case of water, these changes (at a constant pressure) happen at a particular temperature. Ice and water in contact (at a given temperature) will always be at the same temperature (the melting point) no matter what the proportion of ice and water. Adding energy increases the proportion of water until the ice is gone, at that point the temperature again begins to rise as thermal energy is added.

The heat capacity of ice (real ice, in real conditions) is not constant. Very roughly, ice at -40 degrees has only 90% of the heat capacity of ice at the freezing point, and heat capacity continues to fall with temperature from there. The actual thermal energy in ice is the heat capacity integrated over temperature (the area under a heat capacity graph) from absolute zero to the temperature of interest. Absolute zero is the point at which there is no thermal energy present. This is in only in a rough practical sense - it turns out that (due to quantum effects and other weirdness) things are more complicated than that, but not in a way that affect understanding of the Arctic.

As a practical matter, it is almost always the change in thermal energy (or relative amount) we care about - this is why absolute temperature scales are rarely used in everyday life. Common uses for them include calculating the efficiency (among other things) of heat engine cycles, and describing temperatures so low that the freezing point of water is no longer a meaningful reference. They are also handy for calculating heat transfer by radiation to free space (which behaves much as though it were at absolute zero.

Generally speaking, conduction and convection of thermal energy are proportional to temperature difference. This is why 'degree days' are so handy. It is critical when computing temperature differences that the same scale is used - mixing relative and absolute scales or scales with different increments (F and C, K and R) will lead to wrong answers.

So to go back to the original question from Jim Williams, Matt Strassler's explanation was not particularly helpful. While it is true temperature is a measure of mechanical energy per molecule (sort of), there are lots of modes by which a molecule can hold energy. In a (monatomic) ideal gas, it simplifies to translational motion, which is great for classroom physics. In solids, liquids, and real gasses (particularly water vapor) it is much more involved, and changes with temperature. It is not true (nor particularly significant) that  "-172.15°C is 1% more energy than -173.15°C". At 100K water is ice, and its heat capacity is about two thirds that at the freezing point and dropping somewhat faster than linearly with temperature. A quick look did not turn up properties of water ice at lower temperatures, but very roughly, it is reasonable to expect the total thermal energy of ice at -173.15C to be a bit less than 2% higher than at -172.15C.

A later question was "At what temperature is there a 1% energy increase from 0oF [~-17.77oC]?". Again, I can only extrapolate (and also establish reasonable bounds on) properties below 100K, but the answer (by integrating heat capacity with respect to temperature) looks to be very roughly -16.1C or 3F (in other words, from 0F/-17.77C, a 1% increase in total thermal energy will yield a temperature increase of about 5/3rdsC/K or 3F/R). This answer is significantly lower than you'd get by assuming constant heat capacity.

It is fair to say that to speak of a 1% (or any other proportion) change of temperature in a absolute sense on any temperature scale that is not absolute (e.g. F, C) is completely meaningless. It is also, unfortunately, true that for all but a few specific thermodynamic calculations that to speak of a particular proportional change in temperature (in an absolute sense) is also often all but meaningless. Working with proportional changes in temperature difference, over which there is no phase change and the overall span of temperature is reasonable, is perfectly fine.  It is ok for you to feel twice as cold, it is without physical meaning to say any particular temperature is twice as cold as some other temperature.

In the words of NIST (http://cryogenics.nist.gov/Papers/Cryo_Materials.pdf (http://cryogenics.nist.gov/Papers/Cryo_Materials.pdf)),

Models for specific heat began in the 1871 with Boltzmann and were further refined by Einstein and Debye in the early part of the 20th century. While there are many variations of these first models, they generally only provide accurate results for materials with perfect crystal lattice structures. The specific heat of many of the engineering materials of interest here is not described well by these simple models.

I'm not sure this makes things clearer (or will make Jim Williams or others feel better) but the fact is thermodynamics is not a simple science, and many of the simple assertions made above do not stand up to scrutiny.

The good news is, Arctic temperatures may be cold but they are not truly cryogenic. Properties of ice (and water vapor) at Arctic temperatures are well described in engineering literature (and, presumably, have been correctly applied in models heavily dependent on thermodynamics, such as PIOMAS). At some point you have to trust the experts or do a LOT of homework.

Please don't even attempt to understand the physics (or, too often, complete lack of same) behind wind chill numbers. And please don't try to apply wind chill values when calculating degree days or computing your heating bill . . .
Title: Re: Stupid Questions :o
Post by: dj on February 11, 2017, 08:58:37 PM
OK, I gotta wade into this morass . . .

Yes, but is it not better to understand the simple "ideal" relationships first before throwing in all the caveats?   :)

Of course I understood that was only for ideal gases - but grasping that concept first is crucial, don't you think?
Title: Re: Stupid Questions :o
Post by: Tor Bejnar on February 11, 2017, 11:07:45 PM
thanks, Dundee.
Title: Re: Stupid Questions :o
Post by: DaveHitz on February 12, 2017, 01:23:30 AM
Yes, but is it not better to understand the simple "ideal" relationships first before throwing in all the caveats?   :)

Of course I understood that was only for ideal gases - but grasping that concept first is crucial, don't you think?

For me, it depends whether the "simple ideal relationships" have any applicability to the real world.

Physics teachers love to do problems about "friction free environments" (because the math is simpler), but in our everyday lives here on Earth, Aristotle was correct: "Objects in motion tend to come to rest." Physics types will say, "That's because there is always friction, which exerts a force." But that's exactly the point: the friction-free simple case essentially never applies. (Again, I mean here on Earth.)

Likewise, I'm not sure that this simplified concept about ideal gases has any useful relevance to the arctic which consists entirely of solids, liquids, and non-ideal gasses. Especially since much of what's interesting in the arctic is phases changes, which is where the simplified version is furthest from the truth.
Title: Re: Stupid Questions :o
Post by: Jim Williams on February 12, 2017, 02:35:02 AM
Yes, but is it not better to understand the simple "ideal" relationships first before throwing in all the caveats?   :)

Of course I understood that was only for ideal gases - but grasping that concept first is crucial, don't you think?

For me, it depends whether the "simple ideal relationships" have any applicability to the real world.

Physics teachers love to do problems about "friction free environments" (because the math is simpler), but in our everyday lives here on Earth, Aristotle was correct: "Objects in motion tend to come to rest." Physics types will say, "That's because there is always friction, which exerts a force." But that's exactly the point: the friction-free simple case essentially never applies. (Again, I mean here on Earth.)

Likewise, I'm not sure that this simplified concept about ideal gases has any useful relevance to the arctic which consists entirely of solids, liquids, and non-ideal gasses. Especially since much of what's interesting in the arctic is phases changes, which is where the simplified version is furthest from the truth.

I'm with you and I think Dundee finally gave us a meaningful answer.
Title: Re: Stupid Questions :o
Post by: sidd on February 12, 2017, 07:03:57 AM
"Now you are confusing the Boltzmann constant (the measured internal kinetic energy) with the thermodynamic transfer of energy from a "black body" to its surroundings. "

Not at all. But I shall bow out of the discussion now.
Title: Re: Stupid Questions :o
Post by: dj on February 12, 2017, 09:24:41 AM
"Now you are confusing the Boltzmann constant (the measured internal kinetic energy) with the thermodynamic transfer of energy from a "black body" to its surroundings. "

Not at all. But I shall bow out of the discussion now.

I am assuming that if you're measuring the temperature of something, that you have the thermometer embedded within that material.  Thus, you are measuring the conduction or convection, not the radiation, of thermal energy.

Which leads to my own stupid question: 
How is the temperature of ice taken?  Is the temperature a measure making direct contact with the ice (conduction), or is there some space between the thermometer and the ice (radiation)?  Never done it and never thought about it before.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on February 12, 2017, 10:22:41 AM
How the internal temperature of ice is taken? That's a good question. If i remembe correctly, one mehtod was embedding a conductive lead with resistors through the ice, letting refreeze, waiting a couple days, and start sending short elecrtical pulses down the line. The resistors conductivity changes by the temperature it's in so you get the change in local T. Bunch of calibrating happens and we get those nice ice buoy measurements of temperatures.

https://en.m.wikipedia.org/wiki/Electrical_resistivity_and_conductivity#Temperature_dependence
Someone correct that if this went horribly wrong
Title: Re: Stupid Questions :o
Post by: oren on February 12, 2017, 01:46:50 PM
How the internal temperature of ice is taken? That's a good question. If i remembe correctly, one mehtod was embedding a conductive lead with resistors through the ice, letting refreeze, waiting a couple days, and start sending short elecrtical pulses down the line. The resistors conductivity changes by the temperature it's in so you get the change in local T. Bunch of calibrating happens and we get those nice ice buoy measurements of temperatures.

https://en.m.wikipedia.org/wiki/Electrical_resistivity_and_conductivity#Temperature_dependence
Someone correct that if this went horribly wrong
Correct, the O-Buoys have somethings called thermistors. There used to be a good explanation around the forum somewhere regarding these buoys.
Title: Re: Stupid Questions :o
Post by: dj on February 12, 2017, 03:30:32 PM
How the internal temperature of ice is taken? That's a good question. If i remembe correctly, one mehtod was embedding a conductive lead with resistors through the ice, letting refreeze, waiting a couple days, and start sending short elecrtical pulses down the line. The resistors conductivity changes by the temperature it's in so you get the change in local T. Bunch of calibrating happens and we get those nice ice buoy measurements of temperatures.

https://en.m.wikipedia.org/wiki/Electrical_resistivity_and_conductivity#Temperature_dependence
Someone correct that if this went horribly wrong

Thank you very much!

Addendum:  If that is a "good question" is it considered OT for "Stupid questions"?  ;)
Title: Re: Stupid Questions :o
Post by: SteveMDFP on February 12, 2017, 03:48:48 PM

I am assuming that if you're measuring the temperature of something, that you have the thermometer embedded within that material.  Thus, you are measuring the conduction or convection, not the radiation, of thermal energy.

Which leads to my own stupid question: 
How is the temperature of ice taken?  Is the temperature a measure making direct contact with the ice (conduction), or is there some space between the thermometer and the ice (radiation)?  Never done it and never thought about it before.

Conduction, convection, and radiation are mechanisms of heat flux.  When the thermometer is in equilibrium with the thing being measured, there is no net flux by any of these mechanisms.  Any of these mechanisms can bring the thermometer into equilibrium with the thing being measured. 

Imagine you put a hollow sphere of ice in orbit.  A thermometer is suspended in the center, not touching the insides in any way.  The space inside the sphere is a vacuum.  The ice is at, say -10C and the thermometer is at +20 C.  Wait some days.  Eventually the thermometer will radiate heat into the ice, which will not radiate as much heat back to the thermometer.  Equilibrium will eventually be reached, and the thermometer will read -10 (assuming thermal mass of the thermometer is trivial in comparison to the ice). 

In more real-world situations, radiation, convection, and conduction all work together to bring equilibrium, faster than any single mechanism would.
Title: Re: Stupid Questions :o
Post by: dj on February 12, 2017, 03:56:24 PM

I am assuming that if you're measuring the temperature of something, that you have the thermometer embedded within that material.  Thus, you are measuring the conduction or convection, not the radiation, of thermal energy.

Which leads to my own stupid question: 
How is the temperature of ice taken?  Is the temperature a measure making direct contact with the ice (conduction), or is there some space between the thermometer and the ice (radiation)?  Never done it and never thought about it before.

Conduction, convection, and radiation are mechanisms of heat flux.  When the thermometer is in equilibrium with the thing being measured, there is no net flux by any of these mechanisms.  Any of these mechanisms can bring the thermometer into equilibrium with the thing being measured. 

Imagine you put a hollow sphere of ice in orbit.  A thermometer is suspended in the center, not touching the insides in any way.  The space inside the sphere is a vacuum.  The ice is at, say -10C and the thermometer is at +20 C.  Wait some days.  Eventually the thermometer will radiate heat into the ice, which will not radiate as much heat back to the thermometer.  Equilibrium will eventually be reached, and the thermometer will read -10 (assuming thermal mass of the thermometer is trivial in comparison to the ice). 

In more real-world situations, radiation, convection, and conduction all work together to bring equilibrium, faster than any single mechanism would.

True.  I was more interested in whether or not it was via conduction or not. Allowing for the bore hole/hole to refreeze over time means it would be via conduction (not necessarily measuring the temperature of the air within the ice).  I was just curious as I had not thought about it previously.

Stupid questions are not necessarily stupid, as they do give pause to think about things not necessarily considered before.
Title: Re: Stupid Questions :o
Post by: dj on February 12, 2017, 05:06:21 PM
Ok, stupid questions 2-5.  And I am not a statistician, so it may take me a bit to understand any replies (in essence be prepared for additional inquiries).

There is speculation regarding as to when or if we have reached a tipping point in, for example, the Arctic in regards to ice growth/Freeze season as measured by FDDs.

So, statistically speaking:
(1) Would it be appropriate to treat each freeze season separately as a dataset, and run a Chow test on - for example - a regression analysis of the accumulation of FDDs for each freeze season, change in ice volume, extent, or area?

(2) If done, would it then be appropriate to group those freeze seasons that are not statistically different as an appropriate baseline for comparison to those that are (if any) statistically different?

(3) Would this be an appropriate method to determine whether or not a "tipping point" has been achieved?

(4) Has anyone already done an analysis of this type?  Be it on FDDs or the equivalent melt season measure or on the results, i.e. the amount of change in Volume/Extent/Area of Arctic Sea ice?

Edit: I cannot count - it should be 2-5 (given that I already asked one previously).  Thank goodness I am not a Statistician. :D
Title: Re: Stupid Questions :o
Post by: Jim Williams on February 12, 2017, 05:20:39 PM
Chow test: https://en.wikipedia.org/wiki/Chow_test

Interesting notion...doesn't seem to tell you anything about the underlying reasons, but it would tend to tell you if there was a catastrophe or not.

Waiting for the discussion.
Title: Re: Stupid Questions :o
Post by: dj on February 12, 2017, 05:48:13 PM
Chow test: https://en.wikipedia.org/wiki/Chow_test

Interesting notion...doesn't seem to tell you anything about the underlying reasons, but it would tend to tell you if there was a catastrophe or not.

Waiting for the discussion.

True, but would it not allow you to tease out the potential mechanisms?  Part of what I am am thinking is that, for example, for a freeze season the Chow test for FDDs are not statistically different from other seasons but the volume/extent was - then this would be indicative of another mechanism in play (such as warmer water temperatures or stormier weather).  Just a thought.

The other part is that, given that the the baseline (ERA40 or ERA-Interm) and ice measurements appears to be constantly changing would this not allow for a determination of an appropriate "baseline" for comparisons? I am not sure I have worded that well.
Title: Re: Stupid Questions :o
Post by: Jim Williams on February 12, 2017, 06:03:08 PM
True, but would it not allow you to tease out the potential mechanisms?
I will leave the rest of it to others that have more brain cells left, but I don't think so -- at least not directly.

What it will tell you is that if you are traversing an event surface, you have fallen at a particular point from a plane that folded under to the plane below it.   Catastrophe Theory (and game theory) are a bit hard to put into human terms.

If you are running about with one set of coefficients and suddenly you are running about with another set then you have fallen off a cliff.
Title: Re: Stupid Questions :o
Post by: oren on February 12, 2017, 06:40:54 PM
Ok, stupid questions 2-5.  And I am not a statistician, so it may take me a bit to understand any replies (in essence be prepared for additional inquiries).

There is speculation regarding as to when or if we have reached a tipping point in, for example, the Arctic in regards to ice growth/Freeze season as measured by FDDs.

So, statistically speaking:
(1) Would it be appropriate to treat each freeze season separately as a dataset, and run a Chow test on - for example - a regression analysis of the accumulation of FDDs for each freeze season, change in ice volume, extent, or area?

(2) If done, would it then be appropriate to group those freeze seasons that are not statistically different as an appropriate baseline for comparison to those that are (if any) statistically different?

(3) Would this be an appropriate method to determine whether or not a "tipping point" has been achieved?

(4) Has anyone already done an analysis of this type?  Be it on FDDs or the equivalent melt season measure or on the results, i.e. the amount of change in Volume/Extent/Area of Arctic Sea ice?

Edit: I cannot count - it should be 2-5 (given that I already asked one previously).  Thank goodness I am not a Statistician. :D
1. If you mean compare the FDD accumulation for each freezing season, and finding whether recent years break away from a previous clustering, then yes it is appropriate.
2. Yes
3. If you find a statistically significant change then yes. But I doubt you will as of now.
4. Check out the chart showing accumulated FDD anomalies since September of each year.
https://sites.google.com/site/cryospherecomputing/degree-days-freezing (https://sites.google.com/site/cryospherecomputing/degree-days-freezing)
Title: Re: Stupid Questions :o
Post by: zizek on February 12, 2017, 07:11:16 PM
I'm a first year student in a technical program with little background in climate science. Even though it's sort of unrelated to my field, I'm writing a paper about the challenges the Canadian Department of Fisheries and Oceans will face (or are currently facing) due to climate change.  I've been making great progress, and have assembled some great resources dealing with specific issues. But I'm having trouble getting some decent literature on the following topics:

As I understand it, the IPCC has been making some fairly conservative projections. But I'm having difficulty finding any pieces addressing that specifically. This would really help my argument because as far as I know, the government relies heavily on the IPCC.

Is their anything that gives an overview of recent developments in respect to record breaking high temperatures and poor arctic sea ice. I see a lot of papers being posted here, but they seem very specific and go over my head.

My goal with the paper is to describe just how exposed the department is to climate change crisis.

I apologize if this seems like I'm asking you to do my homework.  But this paper is really a thought exercise for myself.  I'm going far above and beyond what an intro to essay writing course is asking for.

If you have any literature that might help my cause, It would be much appreciated. Thanks!

And sorry if this seems like the wrong thread for it. I was gonna post in the science forum, but Stupid Questions thread seemed more suitable :)

Title: Re: Stupid Questions :o
Post by: Neven on February 12, 2017, 07:21:54 PM
Welcome, Slavoj, your profile has been released.

Have you had a look at the latest NOAA Arctic Report Card (http://arctic.noaa.gov/Report-Card/Report-Card-2016/ArtMID/5022/ArticleID/286/Sea-Ice)?
Title: Re: Stupid Questions :o
Post by: Hyperion on February 12, 2017, 08:05:51 PM
"My goal with the paper is to describe just how exposed the department is to climate change crisis."

 ::)
About as exposed as a piece of photographic film wrapped around a fuel rod in a candu reactor.

This planet needs periodic defrost cycles or permafrost and deepsea hydrocarbon reservoirs build up to dangerous levels that could trigger a venus style runaway greenhouse event that boils the oceans and leaves us with 100 atmospheres of pressure and temperatures that would melt lead at sea level. This has been happening on an approximately 150my cycle here for the last billion years. The worst crash, from the perspective of the critters in residence from a glaciated phase, which usually lasts around 50my to a hothouse earth where mostly reptiles and insects are happiest, in this time, was the end Permian event 250 million years ago. but at that time we had one super-continent, Pangaea, with a small icecap at one end, and potential for permafrost carbon and deepsea clathrates was undeniably much less than our current situation. And the current crop of apes have triggered a defrost far more rapid in progress than ever before. Keep your chin up  ;D its a privileged position to be around to witness such a rare event. whether its the death of a planetary biosphere or the critters with the brains to grab the reins and steer the cart away from the cliff actually doing it. Science is hamstrung by only being allowed to speak about the past with certainty. and is yet to recover from bullying by the fossil trolls, so is speaking in over conservative terms about future predictions. The Chinese write crisis with two symbols. One means danger, the other opportunity. Its a good idea to look for the silver lining that generally is hidden in most dark clouds. Order is stagnant chaos is fertile. You are either green and growing, or ripe and rotting.
 8)
Title: Re: Stupid Questions :o
Post by: crandles on February 12, 2017, 08:26:16 PM

As I understand it, the IPCC has been making some fairly conservative projections. But I'm having difficulty finding any pieces addressing that specifically. This would really help my argument because as far as I know, the government relies heavily on the IPCC.

Is their anything that gives an overview of recent developments in respect to record breaking high temperatures and poor arctic sea ice. I see a lot of papers being posted here, but they seem very specific and go over my head.

My goal with the paper is to describe just how exposed the department is to climate change crisis.

You could compare IPCC report saying
Quote
Global mean sea level rise for 2081–2100 relative to 1986–2005 will likely be in the ranges of 0.26 to 0.55 m for RCP2.6, 0.32 to 0.63 m for RCP4.5, 0.33 to 0.63 m for RCP6.0, and 0.45 to 0.82 m for RCP8.5 (medium confidence). For RCP8.5, the rise by the year 2100 is 0.52 to 0.98 m, with a rate during 2081 to 2100 of 8 to 16 mm yr–1 (medium confidence).
These ranges are derived from CMIP5 climate projections in combination with process-based models and literature assessment of glacier and ice sheet contributions (see Figure SPM.9, Table SPM.2). {13.5}

with what experts predicted at similar time. eg
http://www.realclimate.org/index.php/archives/2013/11/sea-level-rise-what-the-experts-expect/ (http://www.realclimate.org/index.php/archives/2013/11/sea-level-rise-what-the-experts-expect/)
and look for similar from previous reports.

Part of the problem with this might be how you deal with statements such as
Quote
Based on current understanding, only the collapse of marine-based sectors of the Antarctic ice sheet, if initiated, could cause global mean sea level to rise substantially above the likely range during the 21st century.

Is that sufficient warming that the IPCC numbers could tend to be on the low side?
Title: Re: Stupid Questions :o
Post by: longwalks1 on February 12, 2017, 08:33:26 PM
Zizek, since I drive past it, if in Winnipeg at the UM  501 University Crescent.  If you live near any other sites in Canada

http://www.dfo-mpo.gc.ca/science/regions/index-eng.htm (http://www.dfo-mpo.gc.ca/science/regions/index-eng.htm)     - stop by and say, "Hi."

Myself, when I research I can go too large for a focus.  Possible subsets of climate impacts on Canadian fisheries are 1.  species migration  and invasive species.  2.  Since plankton is the base, impacts on plankton.  3.  Focus on the West Coast changes or East Coast changes (cod, seals) or arctic basins. 4.  If you want to bring in something novel, maybe explore "the canaries in the coal mine" - usage of marine bird species populations as in indicator of overall health of ecosystems, marine birds as the litmus test.  Yeah, #4 is myself getting a little too carried away.

If you have a technical background, but not grounded in specifics, sites like https://phys.org/ (https://phys.org/)  might serve as an initial search engine.   It is technical enough, but not rigorous, but does give you the direct sources.  Hey, good luck.

Dr. Barber has a new video up also about Arctic change.   
Title: Re: Stupid Questions :o
Post by: Pmt111500 on February 12, 2017, 08:36:58 PM
Part of the problem with this might be how you deal with statements such as
Quote
Based on current understanding, only the collapse of marine-based sectors of the Antarctic ice sheet, if initiated, could cause global mean sea level to rise substantially above the likely range during the 21st century.

Is that sufficient warming that the IPCC numbers could tend to be on the low side?

(sarc) But but, that is totally understandable by those whose lives it mattters the most, that is 4-14 year olds with adhd? (/sarc)

Title: Re: Stupid Questions :o
Post by: dj on February 12, 2017, 09:13:02 PM
Ok, stupid questions 2-5.  And I am not a statistician, so it may take me a bit to understand any replies (in essence be prepared for additional inquiries).

There is speculation regarding as to when or if we have reached a tipping point in, for example, the Arctic in regards to ice growth/Freeze season as measured by FDDs.

So, statistically speaking:
(1) Would it be appropriate to treat each freeze season separately as a dataset, and run a Chow test on - for example - a regression analysis of the accumulation of FDDs for each freeze season, change in ice volume, extent, or area?

(2) If done, would it then be appropriate to group those freeze seasons that are not statistically different as an appropriate baseline for comparison to those that are (if any) statistically different?

(3) Would this be an appropriate method to determine whether or not a "tipping point" has been achieved?

(4) Has anyone already done an analysis of this type?  Be it on FDDs or the equivalent melt season measure or on the results, i.e. the amount of change in Volume/Extent/Area of Arctic Sea ice?

Edit: I cannot count - it should be 2-5 (given that I already asked one previously).  Thank goodness I am not a Statistician. :D
1. If you mean compare the FDD accumulation for each freezing season, and finding whether recent years break away from a previous clustering, then yes it is appropriate.
2. Yes
3. If you find a statistically significant change then yes. But I doubt you will as of now.
4. Check out the chart showing accumulated FDD anomalies since September of each year.
https://sites.google.com/site/cryospherecomputing/degree-days-freezing (https://sites.google.com/site/cryospherecomputing/degree-days-freezing)

Hmm, if a tipping point would be an ice-free summer in the Arctic, perhaps we passed that tipping point in the late-1990's early 2000's?  Unfortunately, tipping points are often unrecognized until after one has fallen out of the canoe and into the water.

Image is attached?  As a noob I am unsure as to how to embed images in a post.

Source:
Walsh, John E., et al. "A database for depicting Arctic sea ice variations back to 1850." Geographical Review 107.1 (2017): 89-107.





Title: Re: Stupid Questions :o
Post by: Hyperion on February 12, 2017, 09:27:20 PM
Don't forget acidification making it impossible for fishes and shellfish and crustaceans  to produce shells for their eggs or the young to form skeletons. Already stopped the mussels being able to reproduce on around 1/4 of New Zealand's coastline. You need to electrify reefs to overcome it.   :(
Title: Re: Stupid Questions :o
Post by: Iceismylife on February 12, 2017, 09:28:15 PM
<snip>

As I understand it, the IPCC has been making some fairly conservative projections. But I'm having difficulty finding any pieces addressing that specifically. This would really help my argument because as far as I know, the government relies heavily on the IPCC.

<snap>
For what it is worth NOAA (US) has issued a warning to the insurance companies of a possible 3m sea level rise by 2050~2060.  Looking at the ice dynamics in Antarctica this is reasonably likely.

The IPCC is smoking really good dope but don't quote me on that.  Their models are broken. Someone on this forum said they were modeling albedo as constant if at all.

For an alternative look https://forum.arctic-sea-ice.net/index.php/topic,1749.0.html this thread makes good reading.
Title: Re: Stupid Questions :o
Post by: Hyperion on February 12, 2017, 09:50:48 PM
Anyone here suffering from Mortality Salience?  ::) Planetry MS sure is a biggy for most. they do anything to distract themselves from having to think about it. ;)

Quote https://en.wikipedia.org/wiki/Mortality_salience
"Potential to cause worldview defense[edit]
Mortality salience has the potential to cause worldview defense, a psychological mechanism that strengthens people's connection with their in-group as a defense mechanism. Studies also show that mortality salience can lead people to feel more inclined to punish minor moral transgressions. One such study divided a group of judges into two groups—one that was asked to reflect upon their own mortality, and one group that was not. The judges were then asked to set a bond for an alleged prostitute. The group that had reflected on mortality set an average bond of $455, while the control group's average bond was $50.[4]
Another study found that mortality salience could cause an increase in support for martyrdom and military intervention. Tom Pyszczynski et al. found that students who had reflected on their mortality showed preference towards people who supported martyrdom, and indicated they might consider martyrdom themselves. They also found that, especially among students who were politically conservative, mortality salience increased support for military intervention, but not among students who were politically liberal.[5] "

from Terror management theory. https://en.wikipedia.org/wiki/Terror_management_theory :

"  TMT is derived from anthropologist Ernest Becker's 1973 Pulitzer Prize-winning work of nonfiction The Denial of Death, in which Becker argues most human action is taken to ignore or avoid the inevitability of death. The terror of absolute annihilation creates such a profound – albeit subconscious – anxiety in people that they spend their lives attempting to make sense of it. On large scales, societies build symbols: laws, religious meaning systems, cultures, and belief systems to explain the significance of life, define what makes certain characteristics, skills, and talents extraordinary, reward others whom they find exemplify certain attributes, and punish or kill others who do not adhere to their cultural worldview. On an individual level, self-esteem provides a buffer against death-related anxiety."
Title: Re: Stupid Questions :o
Post by: Ninebelowzero on February 14, 2017, 05:40:03 AM
According to nullschool The Norwegians appear to have nicked the Polar jetstream.





When are they going to give it back?  8)
Title: Re: Stupid Questions :o
Post by: zizek on February 14, 2017, 02:55:26 PM
Thanks for all the great responses!

This forum is superb.  I don't think I've ever seen a forum with so much high quality content. kudos to the mods and users!
Title: Re: Stupid Questions :o
Post by: gerontocrat on February 14, 2017, 03:25:17 PM
Norwegians have nicked the polar vortex to provide wind for electricity generation  for their electrical vehicles programme. Mind you, they are also opening up new oil fields in the Barents.
Title: Re: Stupid Questions :o
Post by: realitybytes on February 14, 2017, 10:55:49 PM
101 strides is merely one stride more than 100 strides -- it is no percents more.
You haven't put a smiley in there, so I can't tell if you're joking or genuinely confused.

If the standard Stride is 10 cm, then 100 Strides is 1000 cm and 101 Strides is 1010 cm, which is 1% greater.

If the standard Stride is 20 miles, then 100 Strides is 2000 miles and 101 Strides is 2020 miles, which is 1% greater.
Then this is purely a case of liars figure.  1% of which measure?  The previous stride or the current stride?

Jim, I didn't see anyone actually answer your precise question as to "which measure", so I will.

The "which measure" he is referring to as the basis for the percentage change is not the incremental measure of any individual stride, but the sum total distance represented by the starting point - "100 Strides" - and the next (incremental) Stride to get to 101 Strides is indeed exactly 1% more. (I hope this doesn't add to the confusion, but the *next* additional Stride, to get to 102, would be slightly less than 1%, as the basis distance would then be 101 Strides, and the percent increase of distance would be 1/101...)

I'm wondering if the confusion may have arose from the original statement about "-172.15 degrees Celsius" (same as 101 K) having 1% more energy than "-173.15 degrees Celsius" (same as 100 K)... in which case, the "which measure" being used as the basis is 100 K (aka -173.15 degC), and 101 K (aka -172.15 degC) measures exactly 1% more energy than the total energy at 100 K (because K is an absolute measure)

The observation that 1 is infinitely greater percentage than 0 is true, at 1 K vs. 0 K... but much like dividing by zero has no meaning, so does 0 K (other than as a limit, never reachable)
Title: Re: Stupid Questions :o
Post by: Hyperion on February 15, 2017, 06:02:09 PM
Norwegians have nicked the polar vortex to provide wind for electricity generation  for their electrical vehicles programme. Mind you, they are also opening up new oil fields in the Barents.

If they make some Giant Seacrete ( https://en.wikipedia.org/wiki/Biorock ) or Geopolymer ( https://en.wikipedia.org/wiki/Geopolymer )
 heat exchangers instead of concrete oil rigs....

 They could make enough electricity to power all the worlds transport needs by putting turbines on heatpipes  ( https://en.wikipedia.org/wiki/Heat_pipe ) to transfer the heat from the gulfstream up to the south of Greenland meltpool. Put the brakes on this 10x anthro GG global warming effect from the meltpool reducing outgoing long wave over a large area of the earths surface and causing an accelerating runaway greenland melt. And the cyclone canon of the adjacent hot and cold surface waters building up from current ww2 bren gun level that produced 60ft swells in the north atlantic to the 100,000 year ago style revolving six barrel 100mm autogun version, (or even worse considering the much faster rate of change we have triggered) that sent 200 ft waves right across the north Atlantic Ocean to throw 10m plus boulders 6 kms inland and 50m above sea level onto ridgetops in the bahamas.
 Assuming that Hansen and Co's paper before paris had any validity of course.  ::)

I love heatpipes  8)
No moving parts and they have achieved greater per area energy fluxes than the surface of the sun with them in the lab.

 You could even electrolyse the co2 out of the sea and air into hydrocarbon fuel for transport purposes. Then shift reaction the energy into liquid hydrogen later for transport fuel, and sequester the C as char or engineering polymers.
Title: Re: Stupid Questions :o
Post by: binntho on February 17, 2017, 01:26:50 PM
Probably a very stupid question:

I've been following this forum with great interest for some time now, and have accumulated a number of shortcuts to various blogs, information pages, and of course, to Nevens fabulous Arctic Sea Ice Graphs page.

But I keep seeing these interesting and fantastic images posted and far too often I've no idea where they are coming from. Would it be stupid to ask that someone more knowledgeable than me maintained a categorized list of useful sites/links?

What has triggered this question at this time is that I've been looking for the latest HadCrut numbers (an acquaintance of mine has shown me a spurious graph claiming to be from the MetOffice with January 2017 marked in), and during one of my searches I came across this page:

https://moyhu.blogspot.it/p/latest-ice-and-temperature-data.html

Perhaps everybody knows of this page, but for me it looks like a good resource for an amateur wanting to keep abreast of things.
Title: Re: Stupid Questions :o
Post by: josh-j on February 18, 2017, 05:22:56 PM
Here is my stupid question:

DMI 80n graph page says the data is derived from the ECMWF operational model. I can see in the older graph years that ERA40 was used but I don't know what the "operational model" is now.

Basically I want to get the data behind the DMI 80N graph but am struggling to find out where to look. I'm not sure if the values calculated by DMI are available somewhere but cannot see anywhere to obtain from their site?

Thanks for any help :)
Title: Re: Stupid Questions :o
Post by: CalamityCountdown on February 18, 2017, 05:39:40 PM
Arctic sea ice extent on an annual/biannual basis seems to have a tendency to revert to the trend line. Are there changes in the climate that reduce the likelihood that 2018 will be another bounce back year? (which would of course will lead to more alternative facts from the denial-sphere - as reported by  http://greatwhitecon.info/blog/ (http://greatwhitecon.info/blog/))

Title: Re: Stupid Questions :o
Post by: Gray-Wolf on February 18, 2017, 05:50:58 PM
Arctic sea ice extent on an annual/biannual basis seems to have a tendency to revert to the trend line. Are there changes in the climate that reduce the likelihood that 2018 will be another bounce back year? (which would of course will lead to more alternative facts from the denial-sphere - as reported by  http://greatwhitecon.info/blog/ (http://greatwhitecon.info/blog/))

If the past two winters are showing us a big shift in the energy budget across the basin then 'no'!

Title: Re: Stupid Questions :o
Post by: crandles on February 18, 2017, 06:47:06 PM
Here is my stupid question:

DMI 80n graph page says the data is derived from the ECMWF operational model. I can see in the older graph years that ERA40 was used but I don't know what the "operational model" is now.

Basically I want to get the data behind the DMI 80N graph but am struggling to find out where to look. I'm not sure if the values calculated by DMI are available somewhere but cannot see anywhere to obtain from their site?

Thanks for any help :)

See (may need to click link to go to post to get attachment)

No there's not.

Actually there is. For the 2016 numbers see:

ftp.dmi.dk/plus80N_temperatureindex/ (ftp://ftp.dmi.dk/plus80N_temperatureindex/)

For previous years see the attachment, which is actually a ZIP archive.

2017 numbers are now in the ftp site and the zip file doesn't have 2016. Think I can attach the 2016 numbers here
Title: Re: Stupid Questions :o
Post by: josh-j on February 18, 2017, 11:10:24 PM
Thank you very much Crandles, much obliged! And thanks to Jim also. :)
Title: Re: Stupid Questions :o
Post by: Cate on February 21, 2017, 01:24:21 PM
I have a question beyond stupid. :D

Does the term "Arctic sea ice extent" (in the data, discussions, etc) include the large area of coastal pack ice that annually makes it way from the various Arctic waterways down the Labrador coast to the "front" off NE Newfoundland?

Btw, this is the pack that provides the whelping ground for the harp seal and is the traditional ground for the much-maligned Newfoundland seal hunt---or as we call it, the seal fishery.
Title: Re: Stupid Questions :o
Post by: magnamentis on February 21, 2017, 02:05:35 PM
yes and if you want to find out for other regions as well, just watch one of the maps that provide extent data and see whether the ice is on that map or not and whether the average bounderies include that region or not. one example would be this:

as you can see, the region you were asking is included :-)
Title: Re: Stupid Questions :o
Post by: Cate on February 21, 2017, 04:15:00 PM
Thank you, magnamentis. It's interesting to me that that ice in Canadian waters even as far south as the Gulf of St Lawrence is counted as "Arctic" sea ice.
Title: Re: Stupid Questions :o
Post by: Jim Williams on February 21, 2017, 04:56:16 PM
Also, since the picture on the graphs page no longer finds this page for some reason, you can even check to see how those regions are doing at the moment compared to previous years:

https://nsidc.org/data/masie/masie_plots
Title: Re: Stupid Questions :o
Post by: Cate on February 22, 2017, 02:28:14 AM
Also, since the picture on the graphs page no longer finds this page for some reason, you can even check to see how those regions are doing at the moment compared to previous years:

https://nsidc.org/data/masie/masie_plots

Jim, thanks for this---yet another grim line on that graph for the entire NH. Looks like 2017 extent has managed to climb out of the basement only in the past couple of days.
Title: Re: Stupid Questions :o
Post by: magnamentis on February 22, 2017, 02:40:35 AM
Thank you, magnamentis. It's interesting to me that that ice in Canadian waters even as far south as the Gulf of St Lawrence is counted as "Arctic" sea ice.
you're welcome :D

after all it's just a term because 90% of northern hemisphere "sea-ice is in the arctic as to north of the polar circle, while one could as well say "northern hemisphere sea-ice" but i don't think that this is really important as long most people understand the meaning.
Title: Re: Stupid Questions :o
Post by: Tealight on February 28, 2017, 09:22:50 PM
Why is CO2 measured in parts per million and not in kg/m2 ? Wouldn't this give us a better comparison to other greenhouse gases like water vapour? When looking at Mars & Venus we can see that it is not the concentration that matters, but the total mass. Both planets have around 96% CO2 concentration, but only Venus is hot because it has a very thick atmosphere. Mars on the other hand has a thin atmosphere and is very cold.

Using a standard atmosphere I get the following conversion:
Pressure   1013.25   hPa
Pressure   101325   N/m2 (kg⋅m⋅s−2/m2)
accelaration:   9.81   m/s2
Atmosphere mass:   10328.74618   kg /m2
      
CO2 concentration:   405   ppm      
CO2 mass:   4.183   kg/m2
Title: Re: Stupid Questions :o
Post by: DrTskoul on February 28, 2017, 11:27:44 PM
I am sure the ppm of CO2 are in volume. The local concentration of CO2 dictates its absorbance and emissivity of IR. You cannot do any calculations or modeling based on the integral amount above your head. And it would vary based on the local pressure.
Title: Re: Stupid Questions :o
Post by: FredBear on March 01, 2017, 01:47:21 PM
Tealight, the first rule of the computer generation has been KISS (Keep It Simple, Stupid) for the reason that complexity breeds confusion, etc. We don't need to feed Trolls anything they can use to "justify" their attempts to say the goal-posts have been moved.

ppm CO2 as a standard is measured at one place, at altitude and could be affected by volcanic fumes (if the wind blows the wrong way?) or Asian economic activity. The standard is used as a measure of the balance between production and consumption, it cannot tell whether the ocean changes pH - but it does reflect changes in photosynthesis throughout the year! It will be measured in dried air to keep one variable out, produces a clear, simple number (especially when there are 0's in it!) and researchers can relate their discoveries in other fields to it.

In short, measured ppm CO2 is a simple, reliable, trusted, useful, visual tool, with known limitations.
Title: Re: Stupid Questions :o
Post by: DrTskoul on March 01, 2017, 01:52:46 PM
Tealight, the first rule of the computer generation has been KISS (Keep It Simple, Stupid) for the reason that complexity breeds confusion, etc. We don't need to feed Trolls anything they can use to "justify" their attempts to say the goal-posts have been moved.

ppm CO2 as a standard is measured at one place, at altitude and could be affected by volcanic fumes (if the wind blows the wrong way?) or Asian economic activity. The standard is used as a measure of the balance between production and consumption, it cannot tell whether the ocean changes pH - but it does reflect changes in photosynthesis throughout the year! It will be measured in dried air to keep one variable out, produces a clear, simple number (especially when there are 0's in it!) and researchers can relate their discoveries in other fields to it.

In short, measured ppm CO2 is a simple, reliable, trusted, useful, visual tool, with known limitations.

What known limitations? All that it matters for most physical phenomena ( adsorption, diffusion, reaction rates, pickup by the oceans  etc.) depend on concentration. That is the origin of the measure. And it is the simplest result of a sampling analysis. I don't know what's your beef.
Title: Re: Stupid Questions :o
Post by: Shared Humanity on March 01, 2017, 03:31:41 PM
.


In short, measured ppm CO2 is a simple, reliable, trusted, useful, visual tool, with known limitations.

All measures have limitations but they are still useful so long as the yardstick used doesn't change. We have these debates all of the time regarding SIE, SIA and volume. The simple fact is that each are valid, have history to track against, and say what they say about the condition of the Arctic ice. The same goes for CO2.
Title: Re: Stupid Questions :o
Post by: Tealight on March 01, 2017, 06:38:31 PM
I think for photosynthesis or toxicity to humans ppm is a good unit, but for climate analysis it doesn't mean anything without an atmospheric mass/pressure.

I am sure the ppm of CO2 are in volume. The local concentration of CO2 dictates its absorbance and emissivity of IR. You cannot do any calculations or modeling based on the integral amount above your head. And it would vary based on the local pressure.

CO2 concentration alone is a useless unit to do calculations of absorbance and emissivity. 10 CO2 molecules per cm3 at 100% CO2 concentration absorb far less infrared radiation then 50 molecules at 10% CO2 concentration. If another other gas is released into the atmosphere it decreases the CO2 concentration, but the amount of CO2 and its warming effects stay the same.

If you feel funny then you can just release a few trillion tons of whatever gas into the atmosphere and the CO2 concentration will fall by definition to pre-industrial levels. It doesn't stop global warming, but it's enough to fulfill the goals of some lawmakers to bring the CO2 concentration down.
Title: Re: Stupid Questions :o
Post by: FredBear on March 02, 2017, 12:10:19 PM
I think for photosynthesis or toxicity to humans ppm is a good unit, but for climate analysis it doesn't mean anything without an atmospheric mass/pressure.

I am sure the ppm of CO2 are in volume. The local concentration of CO2 dictates its absorbance and emissivity of IR. You cannot do any calculations or modeling based on the integral amount above your head. And it would vary based on the local pressure.

CO2 concentration alone is a useless unit to do calculations of absorbance and emissivity. 10 CO2 molecules per cm3 at 100% CO2 concentration absorb far less infrared radiation then 50 molecules at 10% CO2 concentration. If another other gas is released into the atmosphere it decreases the CO2 concentration, but the amount of CO2 and its warming effects stay the same.

If you feel funny then you can just release a few trillion tons of whatever gas into the atmosphere and the CO2 concentration will fall by definition to pre-industrial levels. It doesn't stop global warming, but it's enough to fulfill the goals of some lawmakers to bring the CO2 concentration down.
"CO2 concentration alone is a useless unit to do calculations of absorbance and emissivity" - but not many of us can even start on that.
CO2 is the changing part of the atmosphere so it is useful to keep measuring the changes as ppm. Oxygen is also consumed by burning fossil fuels but the changes are a tiny percentage. If the atmosphere warms it will have the capacity to hold more water vapour which will increase IR absorbance (but this will vary much more in time & place than a "permanent" gas) - a much more important part of the picture.
"If you feel funny you can just release   .    .   ." - this is not what scientists say is the cure. There are no(?) common gases which would compensate for increased CO2 apart from SO2 at high altitudes to create H2SO4 smog - and no-one wants that falling on their heads.
Anyone with concern knows that the source of the problem is burning fossil fuels, the differences are that the urgency of reduction depends on the perceived magnitude and effects on society of any changes (in environment or economics).
There are much cleverer people around than me, sorry I cannot agree with you that ppm CO2 is not a good measurement to make.
Title: Re: Stupid Questions :o
Post by: Jim Williams on March 02, 2017, 12:52:19 PM
Anyone with concern knows that the source of the problem is burning fossil fuels, the differences are that the urgency of reduction depends on the perceived magnitude and effects on society of any changes (in environment or economics).

I might point out that some of us think the models are completely bogus, and that the changes we are seeing now are due to the Industrial Revolution a couple hundred years ago.  We might not see much value in bothering to try to reduce CO2 anymore, and are here just to watch the show.
Title: Re: Stupid Questions :o
Post by: shmengie on March 02, 2017, 02:12:36 PM
I've been trying to simplify AGW, for my own personal understandings and that I may hopefully better communicate with others.

Tealight's CO₂ atmospheric mass conversion, while it confuses me to a degree, touches on a stupid question thats been bouncing around in my head.

CO₂ was removed from the atmosphere over millions of years by (now) fossilized plants and/or critters through photosynthesis.  That process must have reduced the total weight (and pressure) of the atmosphere.

Now we humans find deposits of oil, gas, coal etc.  Humans are releasing as much CO₂, back into the atmosphere, damn near as quickly as possible (or so it seems).

I look at CO₂ PPM readings as essentially, a net weight gain of mass, to the atmosphere.  Along with more atmospheric mass comes more insulation and thus AGW.
Title: Re: Stupid Questions :o
Post by: Tigertown on March 02, 2017, 03:09:54 PM
From what I know, CO2 initiates warming because of it's ability to absorb longwave radiation or heat and direct a large percentage downward, whereas before it could escape into space. Other processes add to the problem, but it begins with this.
Title: Re: Stupid Questions :o
Post by: binntho on March 02, 2017, 03:13:32 PM
I guess there is some gain in mass, although it's not very significant - an increase in 100 ppm is 0,01 %.

Most of the atmosphere is made up of N2 (78%),  O2 (21%) and Ar (0,9%) - these gases do not cause any real greenhouse effect. As I understand it, the greenhouse effect is caused by molecules that contain different elements - CO2, H2O, CH4 etc. It's the chemical bond between different elements that enable theses molecules to absorb infrared radiation much more strongly than the other molecules/atoms in the atmosphere. The absorbed energy is then radiated out, and the bit that goes downward causes the greenhouse effect.
Title: Re: Stupid Questions :o
Post by: gerontocrat on March 02, 2017, 03:32:21 PM
My stupid question is -
Where can I find the accuracy of Jaxa / NSIDC  measurements of extent, area, volume etc. e.g. 90% confidence interval.
Title: Re: Stupid Questions :o
Post by: Jim Williams on March 02, 2017, 03:35:02 PM
I guess there is some gain in mass, although it's not very significant - an increase in 100 ppm is 0,01 %.

Most of the atmosphere is made up of N2 (78%),  O2 (21%) and Ar (0,9%) - these gases do not cause any real greenhouse effect. As I understand it, the greenhouse effect is caused by molecules that contain different elements - CO2, H2O, CH4 etc. It's the chemical bond between different elements that enable theses molecules to absorb infrared radiation much more strongly than the other molecules/atoms in the atmosphere. The absorbed energy is then radiated out, and the bit that goes downward causes the greenhouse effect.

I'd never heard of nor considered the notion of longwave radiation being because the molecules were composed of differing elements.  My first thought is that seems plausible, but I'd kinda like to have some sort of backup to that statement before I simply accept it.
Title: Re: Stupid Questions :o
Post by: DrTskoul on March 02, 2017, 03:56:55 PM
I guess there is some gain in mass, although it's not very significant - an increase in 100 ppm is 0,01 %.

Most of the atmosphere is made up of N2 (78%),  O2 (21%) and Ar (0,9%) - these gases do not cause any real greenhouse effect. As I understand it, the greenhouse effect is caused by molecules that contain different elements - CO2, H2O, CH4 etc. It's the chemical bond between different elements that enable theses molecules to absorb infrared radiation much more strongly than the other molecules/atoms in the atmosphere. The absorbed energy is then radiated out, and the bit that goes downward causes the greenhouse effect.

I'd never heard of nor considered the notion of longwave radiation being because the molecules were composed of differing elements.  My first thought is that seems plausible, but I'd kinda like to have some sort of backup to that statement before I simply accept it.

Some basic science:

Visualizing Atmospheric Radiation (https://scienceofdoom.com/roadmap/visualizing-atmospheric-radiation/)

Atmospheric Radiation and the “Greenhouse” Effect (https://scienceofdoom.com/roadmap/atmospheric-radiation-and-the-greenhouse-effect/)

Search in that website.  It has many more to explore.

ppm, weight, density, mass, number of molecules, moles, cubic centimeters, all semantics, all can be used indistinguishably. Don't waste your time with semantics.



Title: Re: Stupid Questions :o
Post by: Jim Williams on March 02, 2017, 06:30:32 PM
I guess there is some gain in mass, although it's not very significant - an increase in 100 ppm is 0,01 %.

Most of the atmosphere is made up of N2 (78%),  O2 (21%) and Ar (0,9%) - these gases do not cause any real greenhouse effect. As I understand it, the greenhouse effect is caused by molecules that contain different elements - CO2, H2O, CH4 etc. It's the chemical bond between different elements that enable theses molecules to absorb infrared radiation much more strongly than the other molecules/atoms in the atmosphere. The absorbed energy is then radiated out, and the bit that goes downward causes the greenhouse effect.

I'd never heard of nor considered the notion of longwave radiation being because the molecules were composed of differing elements.  My first thought is that seems plausible, but I'd kinda like to have some sort of backup to that statement before I simply accept it.

Some basic science:

Visualizing Atmospheric Radiation (https://scienceofdoom.com/roadmap/visualizing-atmospheric-radiation/)

Atmospheric Radiation and the “Greenhouse” Effect (https://scienceofdoom.com/roadmap/atmospheric-radiation-and-the-greenhouse-effect/)

Search in that website.  It has many more to explore.

ppm, weight, density, mass, number of molecules, moles, cubic centimeters, all semantics, all can be used indistinguishably. Don't waste your time with semantics.
This might be of interest to others, but as a reply to what I asked about it was the total uselessness of TMI (Too Much Information).  Do you have an explanation handy which devotes itself to how having different elements in a molecule might cause re-emission of longwave radiation without me having to dig about in irrelevant crap?

Hate to be an ass about this....but I think I'm going to be an ass...answer the question usefully or don't try to answer it.
Title: Re: Stupid Questions :o
Post by: Tor Bejnar on March 02, 2017, 07:12:59 PM
It isn't multiple types of atoms in a molecule, but multiple (3+) atoms, period, in a molecule (e.g., O3 absorbs IR):
Quote
In order for molecular vibrations to absorb IR energy, the vibrational motions must change the dipole moment of the molecule. All molecules with three or more atoms meet this criterion and are IR absorbers. While the Earth’s (dry) atmosphere is predominantly composed of non-IR absorbers, N2 (78%), O2 (21%), and Ar (~0.9%), the 0.1% of remaining trace gases contains many species that absorb IR. The absorptions by CO2, CH4, N2O, and O3 are shown in the schematic diagram in the sidebar below.
from
What are the properties of a greenhouse gas? - ACS Climate Science Toolkit | Greenhouse Gases (https://www.acs.org/content/acs/en/climatescience/greenhousegases/properties.html)
Title: Re: Stupid Questions :o
Post by: DrTskoul on March 02, 2017, 07:16:42 PM
I guess there is some gain in mass, although it's not very significant - an increase in 100 ppm is 0,01 %.

Most of the atmosphere is made up of N2 (78%),  O2 (21%) and Ar (0,9%) - these gases do not cause any real greenhouse effect. As I understand it, the greenhouse effect is caused by molecules that contain different elements - CO2, H2O, CH4 etc. It's the chemical bond between different elements that enable theses molecules to absorb infrared radiation much more strongly than the other molecules/atoms in the atmosphere. The absorbed energy is then radiated out, and the bit that goes downward causes the greenhouse effect.

I'd never heard of nor considered the notion of longwave radiation being because the molecules were composed of differing elements.  My first thought is that seems plausible, but I'd kinda like to have some sort of backup to that statement before I simply accept it.

Some basic science:

Visualizing Atmospheric Radiation (https://scienceofdoom.com/roadmap/visualizing-atmospheric-radiation/)

Atmospheric Radiation and the “Greenhouse” Effect (https://scienceofdoom.com/roadmap/atmospheric-radiation-and-the-greenhouse-effect/)

Search in that website.  It has many more to explore.

ppm, weight, density, mass, number of molecules, moles, cubic centimeters, all semantics, all can be used indistinguishably. Don't waste your time with semantics.
This might be of interest to others, but as a reply to what I asked about it was the total uselessness of TMI (Too Much Information).  Do you have an explanation handy which devotes itself to how having different elements in a molecule might cause re-emission of longwave radiation without me having to dig about in irrelevant crap?

Hate to be an ass about this....but I think I'm going to be an ass...answer the question usefully or don't try to answer it.

The absorption/emission of IR depends on the vibration and rotation of bonds and molecules. In its simplest form you can assume a spring ( bond ) connecting two sphere ( atoms ). The spring constant  depends on the strength of the bond ( e.g methane hydrogen single or double bond) and the frequency of vibration dep nds on the mass of the spheres.  If you replace Hydrogen in H2 with oxygen you get a spring/mass system that vibrates more slowly. In order to bring the vibrational frequency to where IR is you get H2O, CO2, CH4 and others. Basically compared to oxygen or nitrogen molecules you need either heavier elements, weaker bonds or more bonds.

Title: Re: Stupid Questions :o
Post by: Jim Williams on March 02, 2017, 07:28:11 PM
I guess there is some gain in mass, although it's not very significant - an increase in 100 ppm is 0,01 %.

Most of the atmosphere is made up of N2 (78%),  O2 (21%) and Ar (0,9%) - these gases do not cause any real greenhouse effect. As I understand it, the greenhouse effect is caused by molecules that contain different elements - CO2, H2O, CH4 etc. It's the chemical bond between different elements that enable theses molecules to absorb infrared radiation much more strongly than the other molecules/atoms in the atmosphere. The absorbed energy is then radiated out, and the bit that goes downward causes the greenhouse effect.

I'd never heard of nor considered the notion of longwave radiation being because the molecules were composed of differing elements.  My first thought is that seems plausible, but I'd kinda like to have some sort of backup to that statement before I simply accept it.

Some basic science:

Visualizing Atmospheric Radiation (https://scienceofdoom.com/roadmap/visualizing-atmospheric-radiation/)

Atmospheric Radiation and the “Greenhouse” Effect (https://scienceofdoom.com/roadmap/atmospheric-radiation-and-the-greenhouse-effect/)

Search in that website.  It has many more to explore.

ppm, weight, density, mass, number of molecules, moles, cubic centimeters, all semantics, all can be used indistinguishably. Don't waste your time with semantics.
This might be of interest to others, but as a reply to what I asked about it was the total uselessness of TMI (Too Much Information).  Do you have an explanation handy which devotes itself to how having different elements in a molecule might cause re-emission of longwave radiation without me having to dig about in irrelevant crap?

Hate to be an ass about this....but I think I'm going to be an ass...answer the question usefully or don't try to answer it.

The absorption/emission of IR depends on the vibration and rotation of bonds and molecules. In its simplest form you can assume a spring ( bond ) connecting two sphere ( atoms ). The spring constant  depends on the strength of the bond ( e.g methane hydrogen single or double bond) and the frequency of vibration dep nds on the mass of the spheres.  If you replace Hydrogen in H2 with oxygen you get a spring/mass system that vibrates more slowly. In order to bring the vibrational frequency to where IR is you get H2O, CO2, CH4 and others. Basically compared to oxygen or nitrogen molecules you need either heavier elements, weaker bonds or more bonds.

OK....how does this obvious then translate into the simple statement "molecules with different elements retransmit more IR"?

I certainly buy into the statement that "different molecules absorb and retransmit photons with different energies."   But the interesting part of the statement was that compounds with different elements re-transmit more IR than those which are composed of the same element.  I think there might be a "fact" there, but I don't know it.
Title: Re: Stupid Questions :o
Post by: Tor Bejnar on March 02, 2017, 08:10:37 PM
From NASA: Climate Roles of H2O, CH4 and CO (https://tes.jpl.nasa.gov/mission/climateroles/)
Quote
Carbon Monoxide

Carbon monoxide (CO) is only a very weak direct greenhouse gas, but has important indirect effects on global warming. Carbon monoxide is an ozone precursor, and also reacts with the hydroxyl (OH) radicals in the atmosphere, reducing their abundance. As OH radicals reduce the lifetimes of many strong greenhouse gases (such as methane), CO indirectly increases the global warming potential of these gases.
So mixed-element molecules with only 2 atoms can also be a greenhouse gas.  I recall reading somewhere GHGs have a certain type of asymmetry ("the vibrational motions must change the dipole moment of the molecule").

Note (previous post) that O3 is a single-element molecule that is a greenhouse gas.


Title: Re: Stupid Questions :o
Post by: DrTskoul on March 02, 2017, 08:15:14 PM
it is a fact in the same sense that during night there is no sunlight.

Simple diatomic molecules have only one vibration mode and it happens that most of them do not have a strong IR spectrum.

Title: Re: Stupid Questions :o
Post by: Tigertown on March 02, 2017, 08:17:10 PM
DrTskoul
Quote
The absorption/emission of IR depends on the vibration and rotation of bonds and molecules. In its simplest form you can assume a spring ( bond ) connecting two sphere ( atoms ). The spring constant  depends on the strength of the bond ( e.g methane hydrogen single or double bond) and the frequency of vibration depends on the mass of the spheres.  If you replace Hydrogen in H2 with oxygen you get a spring/mass system that vibrates more slowly. In order to bring the vibrational frequency to where IR is you get H2O, CO2, CH4 and others. Basically compared to oxygen or nitrogen molecules you need either heavier elements, weaker bonds or more bonds.
                                                 Thank You. That makes sense.
Title: Re: Stupid Questions :o
Post by: johnm33 on March 02, 2017, 08:49:33 PM
A few years ago I was contempating how best to add mass to a building project for heat storage, despite everything I thought I knew it turned out that wood was better than concrete even on an equal volume basis. It's the hydrogen bonds that do it, waters even better but not much use structurally. I vaguely remember something about carbon being the next atom on the scale in this regard.
Title: Re: Stupid Questions :o
Post by: DrTskoul on March 02, 2017, 09:47:48 PM
A few years ago I was contempating how best to add mass to a building project for heat storage, despite everything I thought I knew it turned out that wood was better than concrete even on an equal volume basis. It's the hydrogen bonds that do it, waters even better but not much use structurally. I vaguely remember something about carbon being the next atom on the scale in this regard.

On a mass basis the heat capacity of water is the highest. For building materials timber has around 1200 J/kg/oC. Concrete is at 30% less.
Title: Re: Stupid Questions :o
Post by: Chuck Yokota on March 03, 2017, 05:33:31 AM
With multiple bonds in a molecule, there exist more modes of vibration. In addition to the amount of spring energy in a single bond, the springs could be both stretching at the same time, or one could be stretching while the other is contracting, or the springs could be bending, changing the angle between the bonds. The many more modes of vibration produce many more energy levels for the molecule, with energy differences that fall into the range of IR photons.
Title: Re: Stupid Questions :o
Post by: binntho on March 03, 2017, 07:09:59 AM
I guess there is some gain in mass, although it's not very significant - an increase in 100 ppm is 0,01 %.

Most of the atmosphere is made up of N2 (78%),  O2 (21%) and Ar (0,9%) - these gases do not cause any real greenhouse effect. As I understand it, the greenhouse effect is caused by molecules that contain different elements - CO2, H2O, CH4 etc. It's the chemical bond between different elements that enable theses molecules to absorb infrared radiation much more strongly than the other molecules/atoms in the atmosphere. The absorbed energy is then radiated out, and the bit that goes downward causes the greenhouse effect.

I'd never heard of nor considered the notion of longwave radiation being because the molecules were composed of differing elements.  My first thought is that seems plausible, but I'd kinda like to have some sort of backup to that statement before I simply accept it.

Some basic science:

Visualizing Atmospheric Radiation (https://scienceofdoom.com/roadmap/visualizing-atmospheric-radiation/)

Atmospheric Radiation and the “Greenhouse” Effect (https://scienceofdoom.com/roadmap/atmospheric-radiation-and-the-greenhouse-effect/)

Search in that website.  It has many more to explore.

ppm, weight, density, mass, number of molecules, moles, cubic centimeters, all semantics, all can be used indistinguishably. Don't waste your time with semantics.
This might be of interest to others, but as a reply to what I asked about it was the total uselessness of TMI (Too Much Information).  Do you have an explanation handy which devotes itself to how having different elements in a molecule might cause re-emission of longwave radiation without me having to dig about in irrelevant crap?

Hate to be an ass about this....but I think I'm going to be an ass...answer the question usefully or don't try to answer it.

The absorption/emission of IR depends on the vibration and rotation of bonds and molecules. In its simplest form you can assume a spring ( bond ) connecting two sphere ( atoms ). The spring constant  depends on the strength of the bond ( e.g methane hydrogen single or double bond) and the frequency of vibration dep nds on the mass of the spheres.  If you replace Hydrogen in H2 with oxygen you get a spring/mass system that vibrates more slowly. In order to bring the vibrational frequency to where IR is you get H2O, CO2, CH4 and others. Basically compared to oxygen or nitrogen molecules you need either heavier elements, weaker bonds or more bonds.
Thanks for an excellent explanation of my feeble attempt! It was actually my daughter that pointed this out to me a few years back, she was studying chemistry at the time and claimed it was taught as a basic fact in her course. Whether I understood it correctly, or have presented it correctly, is another thing entirely.

But her explanation was along the same lines as DrTskouls, and the simplest way to explain it is "molecules consisting of different elements make strong greenhouse gases". With my more limited knowledge of chemistry and physics, I at once understood the concept as being logical, but that's all I can claim!
Title: Re: Stupid Questions :o
Post by: Tigertown on March 03, 2017, 07:25:26 AM
It took every bit of my will power not to quote that, just to see what it would look like with one more quote in it.  ;)
Title: Re: Stupid Questions :o
Post by: binntho on March 03, 2017, 08:15:50 AM
It took every bit of my will power not to quote that, just to see what it would look like with one more quote in it.  ;)
Fractal quoting ...
Title: Re: Stupid Questions :o
Post by: DrTskoul on March 03, 2017, 09:30:39 AM
It might lead to another dimension  :P
Title: Re: Stupid Questions :o
Post by: Peter Ellis on March 03, 2017, 11:01:15 AM
OK....how does this obvious then translate into the simple statement "molecules with different elements retransmit more IR"?

It's more the other way round.  All molecules with more than 3 atoms fit the bill.  However, it's very rare to have 3-atom molecules without them including 2 or more elements: ozone is the only gaseous exception I can think of.  Most elements have monoatomic or diatomic molecular forms (if the element has a molecular form at all rather than being crystalline or metallic).
Title: Re: Stupid Questions :o
Post by: Jim Williams on March 03, 2017, 02:22:47 PM
I guess there is some gain in mass, although it's not very significant - an increase in 100 ppm is 0,01 %.

Most of the atmosphere is made up of N2 (78%),  O2 (21%) and Ar (0,9%) - these gases do not cause any real greenhouse effect. As I understand it, the greenhouse effect is caused by molecules that contain different elements - CO2, H2O, CH4 etc. It's the chemical bond between different elements that enable theses molecules to absorb infrared radiation much more strongly than the other molecules/atoms in the atmosphere. The absorbed energy is then radiated out, and the bit that goes downward causes the greenhouse effect.

I'd never heard of nor considered the notion of longwave radiation being because the molecules were composed of differing elements.  My first thought is that seems plausible, but I'd kinda like to have some sort of backup to that statement before I simply accept it.

Some basic science:

Visualizing Atmospheric Radiation (https://scienceofdoom.com/roadmap/visualizing-atmospheric-radiation/)

Atmospheric Radiation and the “Greenhouse” Effect (https://scienceofdoom.com/roadmap/atmospheric-radiation-and-the-greenhouse-effect/)

Search in that website.  It has many more to explore.

ppm, weight, density, mass, number of molecules, moles, cubic centimeters, all semantics, all can be used indistinguishably. Don't waste your time with semantics.
This might be of interest to others, but as a reply to what I asked about it was the total uselessness of TMI (Too Much Information).  Do you have an explanation handy which devotes itself to how having different elements in a molecule might cause re-emission of longwave radiation without me having to dig about in irrelevant crap?

Hate to be an ass about this....but I think I'm going to be an ass...answer the question usefully or don't try to answer it.

The absorption/emission of IR depends on the vibration and rotation of bonds and molecules. In its simplest form you can assume a spring ( bond ) connecting two sphere ( atoms ). The spring constant  depends on the strength of the bond ( e.g methane hydrogen single or double bond) and the frequency of vibration dep nds on the mass of the spheres.  If you replace Hydrogen in H2 with oxygen you get a spring/mass system that vibrates more slowly. In order to bring the vibrational frequency to where IR is you get H2O, CO2, CH4 and others. Basically compared to oxygen or nitrogen molecules you need either heavier elements, weaker bonds or more bonds.
Thanks for an excellent explanation of my feeble attempt! It was actually my daughter that pointed this out to me a few years back, she was studying chemistry at the time and claimed it was taught as a basic fact in her course. Whether I understood it correctly, or have presented it correctly, is another thing entirely.

But her explanation was along the same lines as DrTskouls, and the simplest way to explain it is "molecules consisting of different elements make strong greenhouse gases". With my more limited knowledge of chemistry and physics, I at once understood the concept as being logical, but that's all I can claim!

I can see why someone who's taken Chemistry within the last 10 years or so would be more likely to know this than somone who took Chemistry 40 some years ago.

(And yes I did quote it all....deliberately...why?)
Title: Re: Stupid Questions :o
Post by: Pmt111500 on March 03, 2017, 02:51:01 PM
I guess there is some gain in mass, although it's not very significant - an increase in 100 ppm is 0,01 %.

Most of the atmosphere is made up of N2 (78%),  O2 (21%) and Ar (0,9%) - these gases do not cause any real greenhouse effect. As I understand it, the greenhouse effect is caused by molecules that contain different elements - CO2, H2O, CH4 etc. It's the chemical bond between different elements that enable theses molecules to absorb infrared radiation much more strongly than the other molecules/atoms in the atmosphere. The absorbed energy is then radiated out, and the bit that goes downward causes the greenhouse effect.

I'd never heard of nor considered the notion of longwave radiation being because the molecules were composed of differing elements.  My first thought is that seems plausible, but I'd kinda like to have some sort of backup to that statement before I simply accept it.

Some basic science:

Visualizing Atmospheric Radiation (https://scienceofdoom.com/roadmap/visualizing-atmospheric-radiation/)

Atmospheric Radiation and the “Greenhouse” Effect (https://scienceofdoom.com/roadmap/atmospheric-radiation-and-the-greenhouse-effect/)

Search in that website.  It has many more to explore.

ppm, weight, density, mass, number of molecules, moles, cubic centimeters, all semantics, all can be used indistinguishably. Don't waste your time with semantics.
This might be of interest to others, but as a reply to what I asked about it was the total uselessness of TMI (Too Much Information).  Do you have an explanation handy which devotes itself to how having different elements in a molecule might cause re-emission of longwave radiation without me having to dig about in irrelevant crap?

Hate to be an ass about this....but I think I'm going to be an ass...answer the question usefully or don't try to answer it.

The absorption/emission of IR depends on the vibration and rotation of bonds and molecules. In its simplest form you can assume a spring ( bond ) connecting two sphere ( atoms ). The spring constant  depends on the strength of the bond ( e.g methane hydrogen single or double bond) and the frequency of vibration dep nds on the mass of the spheres.  If you replace Hydrogen in H2 with oxygen you get a spring/mass system that vibrates more slowly. In order to bring the vibrational frequency to where IR is you get H2O, CO2, CH4 and others. Basically compared to oxygen or nitrogen molecules you need either heavier elements, weaker bonds or more bonds.
Thanks for an excellent explanation of my feeble attempt! It was actually my daughter that pointed this out to me a few years back, she was studying chemistry at the time and claimed it was taught as a basic fact in her course. Whether I understood it correctly, or have presented it correctly, is another thing entirely.

But her explanation was along the same lines as DrTskouls, and the simplest way to explain it is "molecules consisting of different elements make strong greenhouse gases". With my more limited knowledge of chemistry and physics, I at once understood the concept as being logical, but that's all I can claim!

I can see why someone who's taken Chemistry within the last 10 years or so would be more likely to know this than somone who took Chemistry 40 some years ago.

(And yes I did quote it all....deliberately...why?)
So that someone could start to speculate how to build a molecule model set with springs? This is not a trivial problem, as you'd need quite a lot of springs of variable strenghts and lengths. Imagine f.e. acetylene where the prospective model builder would have to tension three springs between two balls and the joy of children as it unloads the tension. Probably the set would though include plenty easy-to-swallow parts so it wouldn't be for young children and the elder ones would already have their toy cars, dolls and such... ... No this is not going to sell.
Title: Re: Stupid Questions :o
Post by: Jim Williams on March 03, 2017, 04:58:54 PM
BTW:

...
If you replace Hydrogen in H2 with oxygen you get a spring/mass system that vibrates more slowly. In order to bring the vibrational frequency to where IR is you get H2O, CO2, CH4 and others. Basically compared to oxygen or nitrogen molecules you need either heavier elements, weaker bonds or more bonds.

The first two sentences are the motivation, and the last sentence was the answer.
Title: Re: Stupid Questions :o
Post by: shmengie on March 03, 2017, 06:20:27 PM
gt - Gigaton(s)

1990's - 770 gt natural CO₂, 23 gt CO₂ human released...  Its roughly related to the weight of the raw fossils burnt as how much is forced into the atmosphere.

C₄H₈ (𐄸) has spring at higher temp than water.  When methane (et al.) interact with O₂ in the atmosphere the results are warter and CO₂.   Contained hydro-carbons become additional atmosphere at exhaust point, of what ever human activity, thrives on it.

That spring is part of the pressure of the atmosphere.  Combustion engines turn some of the spring into torque, in planes, trains, car, boats, electric power generation...  Human activity is presently addicted pressure and additional atmosphere inflation activities.

How much energy does it require to conovert CO₂ & water, to hydro-carbons & O₂? 

Plant seeds and water w/the sun do it at surface temps.  We need more artificial processes, because the climate is changing faster than the plants can adapt?
Title: Re: Stupid Questions :o
Post by: D-K Effect on March 04, 2017, 07:30:16 PM
This morning this came across my Twitterwx feed,(RT'd by Joe Bastardi...yeah I know, there's your problem) with no pushback as of yet:
<blockquote class="twitter-tweet" data-lang="en"><p lang="en" dir="ltr">103% Increase In Multi-Year Sea Ice Since 2008 <a href="https://t.co/qLSroMctQB">https://t.co/qLSroMctQB</a> <a href="https://twitter.com/hashtag/Eco?src=hash">#Eco</a> <a href="https://twitter.com/hashtag/Green?src=hash">#Green</a> <a href="https://t.co/hP58XVNRim">pic.twitter.com/hP58XVNRim</a></p>&mdash; The Anti Al Gore (@AGW_IS_A_HOAX) <a href="https://twitter.com/AGW_IS_A_HOAX/status/838002865117396994">March 4, 2017</a></blockquote>
<script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>

Seems counterintuitive given what we know has happened to volume.

Any ideas where this "data" comes from.
Title: Re: Stupid Questions :o
Post by: Neven on March 04, 2017, 08:26:11 PM
Welcome, D-K Effect (your profile has been released).

My guess is that this piece of disinformation was concocted by Steve Goddard, which means that with 99.9% probability you can dismiss it out of hand.
Title: Re: Stupid Questions :o
Post by: D-K Effect on March 04, 2017, 08:58:22 PM
Thanks Neven. That's pretty much what I figured, it saddens me that he can spew this stuff without anyone calling him on it.
Title: Re: Stupid Questions :o
Post by: Neven on March 04, 2017, 09:28:35 PM
I think it's best to ignore it as much as possible. Let him argue with Arctic sea ice and Mother Nature.
Title: Re: Stupid Questions :o
Post by: Martin Gisser on March 04, 2017, 09:55:06 PM
Thanks Neven. That's pretty much what I figured, it saddens me that he can spew this stuff without anyone calling him on it.
Calling him out would not help, but instead backfire: For most of Homo S "Sapiens" truth is a purely social construct. So, being called out by the "rival" other-group would confirm that he is "right", i.e. rightfully belongs to his group, as proven by his intellectual sacrifice.

https://en.m.wikipedia.org/wiki/Sacrifice_of_the_intellect

Methinks ridicule, satire, contempt for his ideas would be more effective. Avoid any hint you take the bullshit or the bullshitter seriously. Very Serious People don't like looking ridiculous. That's all you can do: Help make the bullshit socially unacceptable. You might lose friends on this Quixotic crusade, but there's no other way to save the Planet from the stupid and deluded.

https://krugman.blogs.nytimes.com/2012/02/12/very-serious-question/
Title: Re: Stupid Questions :o
Post by: shmengie on March 09, 2017, 02:13:35 AM
via Nullschool.net
The n. polar vortex looks split in three @ 10hPa

Has anyone plotted the frequency it changes on, oh maybe, a weekly index?
Title: Re: Stupid Questions :o
Post by: Pmt111500 on March 09, 2017, 05:25:16 AM
via Nullschool.net
The n. polar vortex looks split in three @ 10hPa

Has anyone plotted the frequency it changes on, oh maybe, a weekly index?

Ah, the polar night has ended in high stratosphere. The same sort of configuration is not unusual during the change of seasons, but this is a pretty and a clear example. Stratospheric final (hopefully not forever) warming of this spring, please someone correct if that's not it.
Title: Re: Stupid Questions :o
Post by: Tigertown on March 09, 2017, 05:42:16 AM
It started splitting late in Feb., and yes it has been the expectation that this is the SFW for the season.
Title: Re: Stupid Questions :o
Post by: gerontocrat on March 09, 2017, 12:59:44 PM
It started splitting late in Feb., and yes it has been the expectation that this is the SFW for the season.

Presumably the SFW is a physical change to the stratosphere. Does that change extend to mid-latitudes ? (e.g. 50 degrees N.) And does that change include the appearance of the sky ?

I ask because for many years at around this time I look at the sky and one day I say "that's not a winter sky any more".  Am I simply being a silly old fool ?
Title: Re: Stupid Questions :o
Post by: lambertland on March 10, 2017, 03:54:38 PM
[Mod: Your comment has been approved. Welcome to the Arctic Sea ice Forum!]

Hi;

There is a swirl pattern in the sea ice to the east of Zachariae Isstrøm / Nioghalvfjerdsfjorden / North East Greenland on 2016 October 5 shown below:

https://worldview.earthdata.nasa.gov/?p=arctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2016-10-05&z=3&v=234630.99825409323,-1975932.9367040219,1105030.9982540933,-255612.93670402185&r=-90.0000

(East is Top).  My question: is the current flow that is causing this pattern north to south or south to north? (left to right or right to left).  Or is it wind?

Thanks
Title: Re: Stupid Questions :o
Post by: jdallen on March 10, 2017, 05:41:53 PM
[Mod: Your comment has been approved. Welcome to the Arctic Sea ice Forum!]

Hi;

There is a swirl pattern in the sea ice to the east of Zachariae Isstrøm / Nioghalvfjerdsfjorden / North East Greenland on 2016 October 5 shown below:

https://worldview.earthdata.nasa.gov/?p=arctic&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2016-10-05&z=3&v=234630.99825409323,-1975932.9367040219,1105030.9982540933,-255612.93670402185&r=-90.0000

(East is Top).  My question: is the current flow that is causing this pattern north to south or south to north? (left to right or right to left).  Or is it wind?

Thanks
Welcome lambertland;

Most likely wind is the primary driver, but current pulls the ice down along the Greenland coast.

You see feathering of the ice like that frequently in melt zones, as the pack breaks up and broken pieces become more vulnerable to getting pushed around by changes in surface movement and wind.
Title: Re: Stupid Questions :o
Post by: Darvince on March 11, 2017, 09:51:20 AM
Those small swirls are from the general chaoticness of ocean currents. If wind was the driver, then it would fan out in lines like you can see in the Bering Sea more recently here:

http://go.nasa.gov/2muI1CC (http://go.nasa.gov/2muI1CC)
Title: Re: Stupid Questions :o
Post by: zizek on March 11, 2017, 03:58:28 PM
Does anybody have the NOAA Arctic report card downloaded and could upload it somewhere? The site appears to be down :(
Title: Re: Stupid Questions :o
Post by: Pmt111500 on March 11, 2017, 08:16:05 PM
Does anybody have the NOAA Arctic report card downloaded and could upload it somewhere? The site appears to be down :(
Might have it on computer, but not going to dig it up right away... Meanwhile ifls has made sort of a summary... Could be Pruitts (equally crazy) minions have been busy demolishing it from the government site proving once again they do not believe in science. Totally incompetent lot, they are.
Link to ifls summary on report card 2016:
http://www.iflscience.com/environment/2016s-arctic-report-card-temperatures-went-crazy/ (http://www.iflscience.com/environment/2016s-arctic-report-card-temperatures-went-crazy/)
Title: Re: Stupid Questions :o
Post by: Andre on March 12, 2017, 05:16:19 AM
Does anybody have the NOAA Arctic report card downloaded and could upload it somewhere? The site appears to be down :(

Site is back up. See file attached to post.
Title: Re: Stupid Questions :o
Post by: Pmt111500 on March 12, 2017, 06:16:23 AM
Does anybody have the NOAA Arctic report card downloaded and could upload it somewhere? The site appears to be down :(

Site is back up. See file attached to post.

Sorry, I don't have the report card. It's possible I've renamed it to something else.
Title: Re: Stupid Questions :o
Post by: Andre on March 12, 2017, 07:08:20 AM
Does anybody have the NOAA Arctic report card downloaded and could upload it somewhere? The site appears to be down :(

Site is back up. See file attached to post.

Sorry, I don't have the report card. It's possible I've renamed it to something else.

I don't think you meant to quote my post, since I actually uploaded the report card as a PDF along with my post.  ;)
Title: Re: Stupid Questions :o
Post by: johnm33 on March 12, 2017, 11:26:28 PM
Just supposing the ice was so smashed as to be practically liquid, and that every tide that flowed in from the north atlantic displaced ice or water from the upper layer of the arctic,[through CAA Nares, + Fram] how long would it take to flush the ice/top 2m.?
Title: Re: Stupid Questions :o
Post by: magnamentis on March 13, 2017, 05:36:48 PM
Just supposing the ice was so smashed as to be practically liquid, and that every tide that flowed in from the north atlantic displaced ice or water from the upper layer of the arctic,[through CAA Nares, + Fram] how long would it take to flush the ice/top 2m.?

i think no-one can tell because it depends on too many unpredictable variables but then, i'm totally sure, that we shall be able to witness this happening and not so far out and we shall know.

it's not an english saying but it goes about like: it's happening while we're asking when it will happen :-) bad translation perhaps but should be comprehensible at least :-)
Title: Re: Stupid Questions :o
Post by: Darvince on March 13, 2017, 08:36:03 PM
The simple answer is that the question is bad, because the halocline can only disappear when there is no ice, or a current appears where previously one didn't exist. Extreme storms may mix the upper 60 meters or so, but the salt increase of new forming ice will happen until no new ice forms, and the salt dilution of melting ice will happen until there is no ice to melt all year round, i.e. winter ice free Arctic Ocean as well.

Now, unless a massive current appears which flushes across the Arctic Ocean via input from the Atlantic Ocean, and I don't have any numbers on sverdrups or how many sverdrups go through all the ocean's currents each year, but to me that would seem to me quite impossible and so there will be winter sea ice for a long time.

Here are several maps depicting how deep the mixed layer (that is, the surface layer with identical characteristics throughout its entire depth) is throughout the year:
http://s1.postimg.org/f1qylntkv/Mixed_Layer_Depth.gif (http://s1.postimg.org/f1qylntkv/Mixed_Layer_Depth.gif)

https://upload.wikimedia.org/wikipedia/commons/c/c7/Mixed_layer_depth.png (https://upload.wikimedia.org/wikipedia/commons/c/c7/Mixed_layer_depth.png)

In the second one, the months are January and July. You can see that melting ice, most visible in the Antarctic, as well as summer heating, decreases the depth of the mixed layer.

Now, there is also the fact that we have sea ice, however thin, formed in the region between FJL and Svalbard, which according to HYCOM is over 34ppt saltiness. The main thing to note about the link is that the salinity rises in winter as brine leaks out of FYI forming and falls in summer as the FYI melts back into the Ocean. This will continue even after the first ice-free Arctic Ocean happens, as ice does not need ice to grow back on the scale of weather. This can be seen in the Baltic Sea, many northern rivers and lakes, and the Sea of Okhotsk.

https://www7320.nrlssc.navy.mil/hycomARC/navo/arcticsss_nowcast_anim365d.gif (https://www7320.nrlssc.navy.mil/hycomARC/navo/arcticsss_nowcast_anim365d.gif)
Title: Re: Stupid Questions :o
Post by: magnamentis on March 13, 2017, 09:24:31 PM
The simple answer is that the question is bad, because the halocline can only disappear when there is no ice, or a current appears where previously one didn't exist. Extreme storms may mix the upper 60 meters or so, but the salt increase of new forming ice will happen until no new ice forms, and the salt dilution of melting ice will happen until there is no ice to melt all year round, i.e. winter ice free Arctic Ocean as well.

Now, unless a massive current appears which flushes across the Arctic Ocean via input from the Atlantic Ocean, and I don't have any numbers on sverdrups or how many sverdrups go through all the ocean's currents each year, but to me that would seem to me quite impossible and so there will be winter sea ice for a long time.

Here are several maps depicting how deep the mixed layer (that is, the surface layer with identical characteristics throughout its entire depth) is throughout the year:
http://s1.postimg.org/f1qylntkv/Mixed_Layer_Depth.gif (http://s1.postimg.org/f1qylntkv/Mixed_Layer_Depth.gif)

https://upload.wikimedia.org/wikipedia/commons/c/c7/Mixed_layer_depth.png (https://upload.wikimedia.org/wikipedia/commons/c/c7/Mixed_layer_depth.png)

In the second one, the months are January and July. You can see that melting ice, most visible in the Antarctic, as well as summer heating, decreases the depth of the mixed layer.

Now, there is also the fact that we have sea ice, however thin, formed in the region between FJL and Svalbard, which according to HYCOM is over 34ppt saltiness. The main thing to note about the link is that the salinity rises in winter as brine leaks out of FYI forming and falls in summer as the FYI melts back into the Ocean. This will continue even after the first ice-free Arctic Ocean happens, as ice does not need ice to grow back on the scale of weather. This can be seen in the Baltic Sea, many northern rivers and lakes, and the Sea of Okhotsk.

https://www7320.nrlssc.navy.mil/hycomARC/navo/arcticsss_nowcast_anim365d.gif (https://www7320.nrlssc.navy.mil/hycomARC/navo/arcticsss_nowcast_anim365d.gif)

while i thank you and appreciate your elaborations i want to state a few things as to your post:

a) there are no bad questions which is why they are "questions" from those how don't know to someone who might know

b) the answer is not simple for the uninitiated in that field, stating a fact that is known by experts as simple for everyone is condescending and keeps people from asking.

c) "a" and "b" especially appley in the stupid question thread which is exactly meant for people who are not
professionals or savvy in a specific field to ask ANY question without being bashed and calling out a question as bad is, to say it nicely, not so very nice IMNSHO :-)

this said i repeat that i find your contribution related to the question itself very helpful, thanks again, i learned something ;)
Title: Re: Stupid Questions :o
Post by: johnm33 on March 14, 2017, 12:46:05 AM
Darvince, the question was not about the halocline, what I think i'm seeing is an increased flow of Atlantic waters penetrating past FJL/NZ into Laptev before it's energy is spent. Plus it appears to accelerate around the new/full moon peak tide min/max. Assuming that continues and as above the ice is practically liquid, and thus the easiest fraction to flush, how fast could the ice be lost? well i did a boe oom calc. and was surprised by the result. Actually shocked, so wondered if anyone else had any idea.
Title: Re: Stupid Questions :o
Post by: Cid_Yama on March 14, 2017, 02:54:09 AM
This is as much ice as we are going to get.  Delusions are being spun up by those that don't want it to be so, but the March surprise is upon us.

The deniers on this other site I'm on are already trying to claim another 6 months of winter.
Title: Re: Stupid Questions :o
Post by: slow wing on March 14, 2017, 03:14:43 AM
This is as much ice as we are going to get.

Based on what? It's only mid-March. According to PIOMAS, ice volume typically grows into mid-April - so another month or so.

(https://sites.google.com/site/arctischepinguin/home/piomas/grf/piomas-trnd4.png)
Title: Re: Stupid Questions :o
Post by: jdallen on March 14, 2017, 03:32:12 AM
This is as much ice as we are going to get.

Based on what? It's only mid-March. According to PIOMAS, ice volume typically grows into mid-April - so another month or so.

(https://sites.google.com/site/arctischepinguin/home/piomas/grf/piomas-trnd4.png)
I think Cid's - and my - point is, we're going to top out a little early, and possibly quite low - right around 20/21K KM3 for max volume.  I'm figuring things to end up at least 2K KM3 below the previous low volume record.
Title: Re: Stupid Questions :o
Post by: slow wing on March 14, 2017, 04:41:55 AM
OK, that's a different statement. Note however that last year, 2016, didn't top out early and last year also had anomalously high 80N+ temperatures at this time of year.

At the beginning of March this year was about 2K km^3 below 2016 - which topped out as the record min-max (~tied with 2011) - so, yes, it wouldn't be too surprising if we ended up around 2K km^3 below that.
Title: Re: Stupid Questions :o
Post by: Darvince on March 14, 2017, 05:36:02 AM
Darvince, the question was not about the halocline, what I think i'm seeing is an increased flow of Atlantic waters penetrating past FJL/NZ into Laptev before it's energy is spent. Plus it appears to accelerate around the new/full moon peak tide min/max. Assuming that continues and as above the ice is practically liquid, and thus the easiest fraction to flush, how fast could the ice be lost? well i did a boe oom calc. and was surprised by the result. Actually shocked, so wondered if anyone else had any idea.
What was the result? I am suspecting 3 months but I don't have any idea how the calculation would go forth. Then I thought a bit more and suspected 5 years, just based on how far the ice that was originally just off FJL has traveled this winter, but tides are different and much faster ???


a) there are no bad questions which is why they are "questions" from those how don't know to someone who might know

b) the answer is not simple for the uninitiated in that field, stating a fact that is known by experts as simple for everyone is condescending and keeps people from asking.

c) "a" and "b" especially apply in the stupid question thread which is exactly meant for people who are not
professionals or savvy in a specific field to ask ANY question without being bashed and calling out a question as bad is, to say it nicely, not so very nice IMNSHO :-)
;D Yes, I did word the opening quite badly. And not defending myself, but more explaining reason for saying "bad" is that a better word could have been unanswerable, but the question had nothing to do with the halocline so ¯\_(ツ)_/¯

I'll just say that it was quite tangential compared to the first question because I've been somewhat annoyed by the idea that an ice-free Arctic is a fixed state.
Title: Re: Stupid Questions :o
Post by: binntho on March 14, 2017, 07:40:04 AM
I must admit I'm a bit confused when it comes to the halocline and the north-eastern branch of the Gulf Stream that stretches it's fingers all the way to the Arctic Ocean (The North Atlantic Drift).

Several years back I remember reading quite a bit about what drives the Gulf Stream circulation and it's North-Eastern offshoot, and the best explanation I remember was along the lines of there being three main forcings, all of approximately equal importance:

1) Winds blowing mainly towards the North-East over the Atlantic Ocean.

2) Tidal pull from east to west shifts water over the Mid-Atlantic ridge, causing westward movement of deep water. I'm not sure if surface waters are affected, there's an amphidronic point west of Iceland with strong tidal waves moving eastward from there.

3) Cooling and sinking in the far north.

The wind forcing seems to be able to explain fully the main Gulf Stream circulation according to Wikipedia - i.e. it would still be there without the halocline. Wind forcing is also strong towards the North-East along the whole length of the North-Eastern branch of the current, exerting a significant pull.

I'm not so sure about the tidal forcings - perhaps they are insignificant when it comes to driving the Gulf Stream.

The halocline, according to Wikipedia, happens when water evaporates from the surface at mid latitudes, leaving the top layer warmer but saltier than underlying layers and potentially causing vertical instability. But further north, in the Arctic ocean, the reverse seems to be the case - the underlying layers are warmer and saltier than the surface layer, presumably because the warm ocean currents dives under a less saltier lens of cold waters?

The halocline as a driver of ocean currents, on the other hand, as I understand it, is when the ocean freezes, cooling and increasing the salinity of the surface waters, which eventually sink, pulling other surface waters towards the ice-forming region. This is different from point 3 above, where it's only the cooling that causes sinking, not changes in salinity.

Now I may completely have misunderstood the whole thing, hence the "stupid question". But as I understand it, the process of freezing pulls warm surface waters from the south and is at least a local driver of currents. This obviously only works during freezing season (the reverse should be true at other times), and should always pull the warm waters towards the ice edge.

So how will this change over time? If freezing-induced sinking is a pulling force, then the annual amount of pulling should be proportional to the volume of ice freezing? Or is surface freezing more important than thickening later? Is freezing-induced sinking not a positive feedback, in that there presumably is a border line where air temperatures can overcome surface heat, and as the surface warms up due to global warming, this border will shift northwards, pulling the warm waters along with it, delaying ther sinking?

If wind and cooling are the largest forces driving the Gulf Stream, should we be worried about a potential collapse as ocean ice retreats? (Melt-water runoff from Greenland is a different matter).

Now I'm aware that the Gulf Stream has collapsed before, causing the massive temperature swings that can be seen in Greenland ice cores (these cores btw do not measure global temperatures directly, only the surface temperatures of the evaporation zones where the falling snow originates). But these collapses were caused by events vastly bigger in scale than anything on our horizon.

To conclude my ramblings: My understanding of the Gulf Stream and the halocline tells me that a collapse in the Gulf Stream is not imminent, and also, that as sea ice retreats the warm surface waters will seek further and further north, both as a cause and effect.

But even with an all-year ice-free arctic, sinking will always take place due to cooling. Even if the oceans were both totally ice-free and totally salt free, the Gulf Stream would still bring excess warmth from mid latitudes towards the Arctic Ocean.
Title: Re: Stupid Questions :o
Post by: Cid_Yama on March 14, 2017, 07:57:28 AM
Actually I'm betting on less than 20 due to us seeing ice that is not there.  Ice reading as solid when it is 'rotten' full of holes and easily broken up.  And I don't see that ice making it to the end of March considering the conditions the Arctic is about to face.

I certainly don't expect any additional growth that isn't frazil or pancake ice.

As for the AMOC, new ice used to form on the southeastern coast of Greenland and the brine expulsion was a significant driver.  No more.

As for the Atlantic Water current, in submerges near Svalbard and heads toward the Laptev Sea warming sediments on the shelf there.

 

 
Title: Re: Stupid Questions :o
Post by: Jim Williams on March 14, 2017, 01:36:37 PM
Just supposing the ice was so smashed as to be practically liquid, and that every tide that flowed in from the north atlantic displaced ice or water from the upper layer of the arctic,[through CAA Nares, + Fram] how long would it take to flush the ice/top 2m.?

i think no-one can tell because it depends on too many unpredictable variables but then, i'm totally sure, that we shall be able to witness this happening and not so far out and we shall know.

it's not an english saying but it goes about like: it's happening while we're asking when it will happen :-) bad translation perhaps but should be comprehensible at least :-)
I think the English equivalent would be "Look out your window."
Title: Re: Stupid Questions :o
Post by: Jim Williams on March 14, 2017, 02:06:37 PM
...
But even with an all-year ice-free arctic, sinking will always take place due to cooling. Even if the oceans were both totally ice-free and totally salt free, the Gulf Stream would still bring excess warmth from mid latitudes towards the Arctic Ocean.

I think the flies in the ointment here are Asia and North America.  Land both warms and cools more rapidly than water.  So, what the Gulf Stream giveth Asia taketh away.

On the scale of a couple thousand years you get extreme warming.  On the scale of 10s of thousands of years you get extreme cooling.  On the scale of eons you get a wild flip-flop.
Title: Re: Stupid Questions :o
Post by: Jim Williams on March 14, 2017, 02:17:42 PM
My stupid question of the day:  Are there any climate models out there that use system dynamics rather than trying to model a natural system for any length of time by pretending it is a linear vector space and using arrays of differential equations?
Title: Re: Stupid Questions :o
Post by: seaicesailor on March 14, 2017, 02:37:15 PM
My stupid question of the day:  Are there any climate models out there that use system dynamics rather than trying to model a natural system for any length of time by pretending it is a linear vector space and using arrays of differential equations?
It is difficult to understand the question Jim, because I see both options you give as equivalent. An array of differential equations applied over a vectorial quantity ("linear"?) or several scalar and vectorial quantities, can be a mathematical model of a dynamical system, suitable for performing computations and developing predictions of the underlying dynamical system.
Title: Re: Stupid Questions :o
Post by: Jim Williams on March 14, 2017, 03:12:28 PM
My stupid question of the day:  Are there any climate models out there that use system dynamics rather than trying to model a natural system for any length of time by pretending it is a linear vector space and using arrays of differential equations?
It is difficult to understand the question Jim, because I see both options you give as equivalent. An array of differential equations applied over a vectorial quantity ("linear"?) or several scalar and vectorial quantities, can be a mathematical model of a dynamical system, suitable for performing computations and developing predictions of the underlying dynamical system.

To oversimplify, I am interested in a model that represents information as sources and sinks, and the system as buckets.  In the extreme, the information would be represented as single photons, but that is clearly not computable with current hardware (unless you count the Universe as current hardware).

Fields are a pretty approximation when you are only guessing 10 days out.  They really suck bad over the long haul.  (There is nothing less real than a Real number.)

Title: Re: Stupid Questions :o
Post by: ktonine on March 14, 2017, 03:34:05 PM
My stupid question of the day:  Are there any climate models out there that use system dynamics rather than trying to model a natural system for any length of time by pretending it is a linear vector space and using arrays of differential equations?
It is difficult to understand the question Jim, because I see both options you give as equivalent. An array of differential equations applied over a vectorial quantity ("linear"?) or several scalar and vectorial quantities, can be a mathematical model of a dynamical system, suitable for performing computations and developing predictions of the underlying dynamical system.

To oversimplify, I am interested in a model that represents information as sources and sinks, and the system as buckets.  In the extreme, the information would be represented as single photons, but that is clearly not computable with current hardware (unless you count the Universe as current hardware).

Fields are a pretty approximation when you are only guessing 10 days out.  They really suck bad over the long haul.  (There is nothing less real than a Real number.)

Per Wiki: (https://en.wikipedia.org/wiki/Global_Environmental_Multiscale_Model)
... model dynamics is formulated in terms of the hydrostatic primitive equations with a terrain following pressure vertical coordinate (h). The time discretization is an implicit two-time-level semi-Lagrangian scheme. The spatial discretization is a Galerkin grid-point formulation on an Arakawa C-grid in the horizontal (lat-lon) and an unstaggered vertical discretization. The horizontal mesh can be of uniform or variable resolution, and furthermore can be arbitrarily rotated, the vertical mesh is also variable. The explicit horizontal diffusion is -2 on all prognostic variables.

The operational GEM model is interfaced with a full complement of physical parametrizations, these currently include:

Title: Re: Stupid Questions :o
Post by: RoxTheGeologist on March 14, 2017, 03:57:22 PM
Darvince, the question was not about the halocline, what I think i'm seeing is an increased flow of Atlantic waters penetrating past FJL/NZ into Laptev before it's energy is spent. Plus it appears to accelerate around the new/full moon peak tide min/max. Assuming that continues and as above the ice is practically liquid, and thus the easiest fraction to flush, how fast could the ice be lost? well i did a boe oom calc. and was surprised by the result. Actually shocked, so wondered if anyone else had any idea.

The Atlantic water is thought to flow around the whole of the Arctic Nansen Basin beneath the polar mixed layer, circulating counter clockwise. A-Team showed that the edge of the ice through most of the summer corresponded with bathymetry. Warmer Atlantic water flows down the continental slope to form a layer starting at around 300m depth, Where the Atlantic water is at the surface, on the continental shelf, ice melts. Within the deeper basin the Atlantic water no longer affects the ice as it is too deep, unless the denser warm water remains on the surface; that requires a break down of the Halocline. The Halocline is refreshed by freshwater input from rivers and from melting ice.
Title: Re: Stupid Questions :o
Post by: Jim Williams on March 14, 2017, 04:22:47 PM