Support the Arctic Sea Ice Forum and Blog

Author Topic: "Stupid" Questions :o  (Read 464888 times)

Shared Humanity

  • Young ice
  • Posts: 3816
    • View Profile
  • Liked: 318
  • Likes Given: 37
Re: "Stupid" Questions :o
« Reply #2250 on: July 15, 2019, 03:40:15 PM »
I'm interested in exploring the relationship / correlation between water temp and depth.

Then you need to read up on salinity too. That is basically oceanography.

You might find Shakhova et al 2019 interesting.

Quote
In the ESAS, sea water is much warmer
than air (mean annual air temperature of −10 ◦C vs. mean annual sea water temperature of −1
◦C).


Consequently, the subsea permafrost has warmed by up to 17 ◦C during the last 12 kyrs [23,32]. It
has been suggested that the following factors determine the evolution of subsea permafrost after
inundation:

https://www.mdpi.com/2076-3263/9/6/251

Thanks for the link. I realize salinity has a role to play in density and water layers. All things being equal, salty water is denser and generally sinks below fresh water.

At this point I'm trying to keep it as simple as possible and isolate the variables. Perhaps it's incorrect, but I'm working with an assumption of 1 layer in 10m deep coastal water.

It is a mistake to think that deeper waters are colder than surface waters. Depending on currents, this is often not the case. Melting of the permafrost has little if anything to do with geothermal energy and almost everything to do with the temperatures of the water if submerged and temperatures of the air if not.

Worse still, once thermokarsts have formed due to the degradation of the permafrost in one area, this spreads rapidly.
« Last Edit: July 15, 2019, 03:57:41 PM by Shared Humanity »

gerontocrat

  • First-year ice
  • Posts: 5812
    • View Profile
  • Liked: 962
  • Likes Given: 18
Re: "Stupid" Questions :o
« Reply #2251 on: July 15, 2019, 03:45:53 PM »
Depth matters for when methane is released. The greater the depth, the less CH4 reaches the surface, especially if release is slow in little bubbles. 
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

binntho

  • Grease ice
  • Posts: 760
    • View Profile
  • Liked: 186
  • Likes Given: 52
Re: "Stupid" Questions :o
« Reply #2252 on: July 15, 2019, 03:55:07 PM »
Depth matters for when methane is released. The greater the depth, the less CH4 reaches the surface, especially if release is slow in little bubbles.
Since most of the methane dissolves in the sea water on the way up - we hope!

SteveMDFP

  • Nilas ice
  • Posts: 1355
    • View Profile
  • Liked: 148
  • Likes Given: 12
Re: "Stupid" Questions :o
« Reply #2253 on: July 15, 2019, 04:07:57 PM »
Depth matters for when methane is released. The greater the depth, the less CH4 reaches the surface, especially if release is slow in little bubbles.

Of course, with brisk seeps in relatively shallow waters, we can expect the whole water column to become saturated with dissolved methane, at which point the released methane does reach the surface.

And each molecule of dissolved methane will, by biological processes, consume two molecules of oxygen.  Oxygen is a scarce commodity in the oceans.  Methane release anywhere in the oceans can exacerbate ocean hypoxia.  What happens when the cold, oxygenated waters that leave the arctic at depth (to replenish oxygen in the whole Atlantic ocean) cease being oxygenated?

Rich

  • Guest
Re: "Stupid" Questions :o
« Reply #2254 on: July 15, 2019, 04:11:50 PM »
Depth matters for when methane is released. The greater the depth, the less CH4 reaches the surface, especially if release is slow in little bubbles.

Of course, with brisk seeps in relatively shallow waters, we can expect the whole water column to become saturated with dissolved methane, at which point the released methane does reach the surface.

And each molecule of dissolved methane will, by biological processes, consume two molecules of oxygen.  Oxygen is a scarce commodity in the oceans.  Methane release anywhere in the oceans can exacerbate ocean hypoxia.  What happens when the cold, oxygenated waters that leave the arctic at depth (to replenish oxygen in the whole Atlantic ocean) cease being oxygenated?
.

(1) CH4 + (2) O2 ==> (2) H2O + (1) CO2 ?????

SteveMDFP

  • Nilas ice
  • Posts: 1355
    • View Profile
  • Liked: 148
  • Likes Given: 12
Re: "Stupid" Questions :o
« Reply #2255 on: July 15, 2019, 04:23:56 PM »
Depth matters for when methane is released. The greater the depth, the less CH4 reaches the surface, especially if release is slow in little bubbles.

Of course, with brisk seeps in relatively shallow waters, we can expect the whole water column to become saturated with dissolved methane, at which point the released methane does reach the surface.

And each molecule of dissolved methane will, by biological processes, consume two molecules of oxygen.  Oxygen is a scarce commodity in the oceans.  Methane release anywhere in the oceans can exacerbate ocean hypoxia.  What happens when the cold, oxygenated waters that leave the arctic at depth (to replenish oxygen in the whole Atlantic ocean) cease being oxygenated?
.

(1) CH4 + (2) O2 ==> (2) H2O + (1) CO2 ?????

Yes. I believe this is called stoichiometry, from my ancient chemistry studies.  The arrow can be interpreted to mean "complicated bacterial processes."  Combustion does it faster, but combustion is hard to accomplish in cold arctic waters.  ;-)

RoxTheGeologist

  • Frazil ice
  • Posts: 432
    • View Profile
  • Liked: 99
  • Likes Given: 81
Re: "Stupid" Questions :o
« Reply #2256 on: July 15, 2019, 05:46:12 PM »
Depth matters for when methane is released. The greater the depth, the less CH4 reaches the surface, especially if release is slow in little bubbles.

Of course, with brisk seeps in relatively shallow waters, we can expect the whole water column to become saturated with dissolved methane, at which point the released methane does reach the surface.

And each molecule of dissolved methane will, by biological processes, consume two molecules of oxygen.  Oxygen is a scarce commodity in the oceans.  Methane release anywhere in the oceans can exacerbate ocean hypoxia.  What happens when the cold, oxygenated waters that leave the arctic at depth (to replenish oxygen in the whole Atlantic ocean) cease being oxygenated?

Look at the black sea stratification and euxinic bottom waters.

Ocean anoixia is thought to have been responsible for mass extinctions in the oceans in the Paleozic and Meoszoic such as the early Toarcian


https://www.sciencedirect.com/science/article/pii/S0031018211005694

Its a very good reason NOT to do oceanic iron fertilization. For it to work the carbon either has to be dissolved into the ocean (promoting acidification) or it has to fall to the sea floor, and the latter only happens if you run out ox oxygen; causing mass death of sea creatures.



jdallen

  • Young ice
  • Posts: 3003
    • View Profile
  • Liked: 174
  • Likes Given: 168
Re: "Stupid" Questions :o
« Reply #2257 on: July 15, 2019, 10:13:50 PM »
<snip>
<snip>
<snip>
I'm interested in exploring the relationship / correlation between water temp and depth. If you're game we can try that. If not, also OK.

The flow of geothermal heat is pretty consistent, and very, very small... on the order of only 87 MILLIwatts per square meter.  You'll get some higher concentrations in active geothermal/volcanic zones, but that's the average over all.

That's the reason why you get 100s of meters of permafrost in Arctic zones because the heat flow is to low to prevent it from forming until reaching a depth where the thermal balance is reached between water freezing and heat loss.  If the Arctic were in permanent darkness (e.g. if the Earth were tidally locked with the sun), that freezing zone would extend down through most of the crust.

What keeps things locking up further during Polar night is heat flows from outside of the region bringing in heat to offset loss from the top of the atmosphere.

Permafrost on ocean shelves like the ESS is actually an artifact left over from the last glaciation, when the shelves in question were exposed.  Clathrates which have formed do so naturally, and can form at fairly high temperatures, as pressure is a factor in their formation - there's actually a lot of them at depth in the Gulf of Mexico for example, as you have methane release, low temperatures and very high pressure..

The melting of both (clathrates and sub-sea level permafrost) is driven much more by heat carried by water on the shelves, captured during the melt season, or imported by currents, and is understandably low considering the usual low temperature of sea water, which is low enough that pure water ice won't melt if it is protected against intrusion by salt.

So, all in all, you really aren't going to get any heat input from Geothermal sources in the Arctic worth mentioning as contributers to any melt we see.
This space for Rent.

Stephan

  • Grease ice
  • Posts: 606
    • View Profile
  • Liked: 127
  • Likes Given: 89
Re: "Stupid" Questions :o
« Reply #2258 on: July 16, 2019, 07:34:05 PM »

And each molecule of dissolved methane will, by biological processes, consume two molecules of oxygen.  Oxygen is a scarce commodity in the oceans.  Methane release anywhere in the oceans can exacerbate ocean hypoxia.  What happens when the cold, oxygenated waters that leave the arctic at depth (to replenish oxygen in the whole Atlantic ocean) cease being oxygenated?

Is there any evidence or measurements of the oxygen content of ESS/Chukchi shelf waters where a lot of CH4 is supposed to escape from the sea floor into the sea water, at first dissolved and then oxidised?

UCMiami

  • New ice
  • Posts: 73
    • View Profile
  • Liked: 24
  • Likes Given: 37
Re: "Stupid" Questions :o
« Reply #2259 on: July 17, 2019, 09:22:47 PM »
Hoping someone can point me to a detailed map of the boundaries of the various 'arctic seas' - specifically the boundary between the Hudson the Baffin and the CAA - Foxe Basin and the Hudson Strait belong in which 'sea'?

Thanks

philopek

  • Frazil ice
  • Posts: 254
    • View Profile
    • Nutrition Secure Solutions
  • Liked: 89
  • Likes Given: 30
Re: "Stupid" Questions :o
« Reply #2260 on: July 17, 2019, 09:38:21 PM »
Hoping someone can point me to a detailed map of the boundaries of the various 'arctic seas' - specifically the boundary between the Hudson the Baffin and the CAA - Foxe Basin and the Hudson Strait belong in which 'sea'?

Thanks

They're almost identical but still, therefore thought to post both to cover m.a.

oren

  • Young ice
  • Posts: 4180
    • View Profile
  • Liked: 679
  • Likes Given: 1191
Re: "Stupid" Questions :o
« Reply #2261 on: July 17, 2019, 09:44:43 PM »
And of course, the "CT" map used by Wipneus. Though I believe Hudson Bay demarcation is the same - Hudson Strait and Foxe Basin both belong in it.


UCMiami

  • New ice
  • Posts: 73
    • View Profile
  • Liked: 24
  • Likes Given: 37
Re: "Stupid" Questions :o
« Reply #2262 on: July 17, 2019, 10:52:29 PM »
Philopek and Oren - thanks so much - it is exactly as I suspected but didn't want to make a fool of myself. Interesting to note that there is a significant difference in the southern extent of CAB toward Canada, Alaska, and Asia between the wipneus map and the other two - probably explains the difference in CAB area between various graphs displayed on other threads

Do either of you know of where I could find total surface area numbers for the various seas based the different definitions.

oren

  • Young ice
  • Posts: 4180
    • View Profile
  • Liked: 679
  • Likes Given: 1191
Re: "Stupid" Questions :o
« Reply #2263 on: July 17, 2019, 11:04:27 PM »
For the inner seas total surface area I use the max of the annual extent for each region. The data files for NSIDC and UH can be found on arctischepinguin. I have no numbers for the outer seas.

binntho

  • Grease ice
  • Posts: 760
    • View Profile
  • Liked: 186
  • Likes Given: 52
Re: "Stupid" Questions :o
« Reply #2264 on: July 19, 2019, 07:44:43 AM »
Per Windy.com, several regions receiving snow at the moment.

ESS, Chuchki and CAB.
Not sure how reliable that is. If you check accumulated rain for the same areas, you see rain. So perhaps some sleet?

Now for the stupid question:

I seem to remember that in the far north, the clouds that produce precipitation can be either frozen or not - i.e. they contain either ice crystals or water droplets.

Whether an area with temps hovering around freezing receives rain or snow from a given cloud is to a large extent dependent on the state of liquid in that cloud.

I was hoping that somebody with the necessary knowledge could confirm or refute this, and perhaps also say something about the likelyhood of snow / rain falling at different times in the Arctic, irrespective of the temperatures being slightly above or below zero Centigrades.

Threebellies

  • New ice
  • Posts: 3
    • View Profile
  • Liked: 0
  • Likes Given: 1
Re: "Stupid" Questions :o
« Reply #2265 on: July 21, 2019, 01:04:48 AM »
I figured this was an appropriate place to ask this question. Perhaps there a fields within literature I am unaware of, and this is viewed perhaps from a mass balance/out of the realm possibility by Article climatologists and sea ice specialists.

However, my question in general is this: Antarctica is a large mass of grounded ice surrounded by sea ice where it can seasonally be sustained. One would presume this is a natural thing the ice sheets cause: formation of peripheral sea ice which supports the overall land based ice sheet system in a very broad sense.

In the case of the Arctic, where is such an ice sheet to be found? I suppose there are a few I’ve caps on islands in Svalbard, the CAA, and perhaps some Russian Arctic islands. In large part, however, the literal elephant in the Arctic is Greenland. It has the only real ice sheet type geological formations somewhat like Antarctica, in the Arctic.

Does the amount of fresh minty water, glaciers and other large bergs of ice which get calves off of (or pushed perhaps) Northern Greenland (and Greenlandic shores >80 north in latitude) have a large impact in the existence and overall formation of ice at latitudes greater than 80, 90 degrees? The Artic isn’t a terribly large, deep ocean. Perhaps Greenland “feeds” the CAB and by extension, peripheral Artic seas in such a way that even inputting tons and tons of energy into the system (as we’re doing) isn’t enough to offset the rush of cold water perfectly primed for freezing and or Greenlandic ice into the Arctic Ocean?

Does Greenland act like a whole bunch of ice cubes in an otherwise somewhat closed Artic system, allowing cold conditions and ice to persist longer into the future, in waters we may have presumed would warm?

In the same way the area southeast of Greenland in the Fram strait to the west and southwest of Iceland is one of the few areas expected to drop in temperatures over the coming years (presumably from tons of Greenland melt), wouldn’t largely equivalent amounts of water be likely being shed in the north perhaps where melting seasons are much shorter, and despite rising temps in those coastal areas of Greenland in the north already(~20 deg C in July 2019) mean the water there at best will always hover near freezing, so long as Greenland is shedding ice and fresh, minty water by the gigatons?

Input is greatly appreciated, especially if someone could roughly show me mass balances of those areas and prove to me that oceanic conditions are largely the driver for the existence of the >80 deg polar Arctic ice cap each year.

The onset and relationships between Arctic and Greenlandic melt seasons, are they so easily dismissed and ignored because of very good reasons?

https://arctic.noaa.gov/Report-Card/Report-Card-2016/ArtMID/5022/ArticleID/277/Greenland-Ice-Sheet

Even tertiary reading of articles such as above show that the 2012 melt season and following year were crazy in Greenland, almost as if it were feeding its Arctic pal, the sea ice.

be cause

  • Grease ice
  • Posts: 806
  • Citizenship .. a Lurker gets asylum
    • View Profile
  • Liked: 182
  • Likes Given: 169
Re: "Stupid" Questions :o
« Reply #2266 on: July 21, 2019, 07:42:12 PM »
Any news of Piomas ?
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 ...

philopek

  • Frazil ice
  • Posts: 254
    • View Profile
    • Nutrition Secure Solutions
  • Liked: 89
  • Likes Given: 30
Re: "Stupid" Questions :o
« Reply #2267 on: July 21, 2019, 09:43:13 PM »
Any news of Piomas ?

Summer holidays, reduced staff or WIP is on holiday.

Whatever it is, i'm looking forward to that as well because i expect a big negative surprise for many.

BTW i'm expecting a few multi-century drops during the next 2-3 weeks. there is quite a lot of around 50% concentration ice relatively far south and a few days of sunshine and warm winds with decent waves will finish that off below the 15% threshold.

If it were mid to end august it would be a 50:50 thing but at this time of the year i fear that
it will happen, else we would have to reconsider the accuracy of all the maps we're using.

petm

  • Grease ice
  • Posts: 589
    • View Profile
  • Liked: 269
  • Likes Given: 21
Re: "Stupid" Questions :o
« Reply #2268 on: July 21, 2019, 10:01:46 PM »
It has been stated in the melting thread that there's a possibility of a huge high pressure ridge forming over the Arctic Ocean, and that if it happens it will be very bad for the ice.

But would a huge high pressure ridge be bad for ice retention, and why? Just because insolation is still high for a few more weeks? But wouldn't it also bring an end to the winds? Wouldn't big storms be worse?

philopek

  • Frazil ice
  • Posts: 254
    • View Profile
    • Nutrition Secure Solutions
  • Liked: 89
  • Likes Given: 30
Re: "Stupid" Questions :o
« Reply #2269 on: July 21, 2019, 10:09:43 PM »
It has been stated in the melting thread that there's a possibility of a huge high pressure ridge forming over the Arctic Ocean, and that if it happens it will be very bad for the ice.

But would a huge high pressure ridge be bad for ice retention, and why? Just because insolation is still high for a few more weeks? But wouldn't it also bring an end to the winds? Wouldn't big storms be worse?

IMO it will help to kill the reminder below 75N that is currently around 50% concentration but it will help to retain ice above 80N because the sun is losing it's power up there rapidly by the day.

There may be about 1 week max of damaging insolation, i can't tell exactly.

BTW the same question you asked in the MST came to me the moment i was reading all the exited posts that, if it were mid june to mid july, were true, but people get used to keywords and key-events, often forgetting that the high season for a specific pattern is over or at least reduced and almost over.

I did not ask the question because i follow this forum over many many years and i'd have been surprised if no-one of the dooms-dayers had jumped on it the way it happened.

You know, some people are here for entertainment and killing time obviously and they need ACTION, else they get bored and get mute for days and weeks until the next CHANCE of WHOWS is raising at the horizon.

It is and was a legit question and i'm glad you asked while it's sad that one has to refrain from asking such questions to not get bashed and involved an back and forth bickering.

Limited minds are mostly at the same time stubborn, eager not to lose their face and FAITH ;)




petm

  • Grease ice
  • Posts: 589
    • View Profile
  • Liked: 269
  • Likes Given: 21
Re: "Stupid" Questions :o
« Reply #2270 on: July 21, 2019, 10:25:38 PM »
It has been stated in the melting thread that there's a possibility of a huge high pressure ridge forming over the Arctic Ocean, and that if it happens it will be very bad for the ice.

But would a huge high pressure ridge be bad for ice retention, and why? Just because insolation is still high for a few more weeks? But wouldn't it also bring an end to the winds? Wouldn't big storms be worse?
BTW the same question you asked in the MST came to me the moment i was reading all the exited posts that, if it were mid june to mid july, were true, but people get used to keywords and key-events, often forgetting that the high season for a specific pattern is over or at least reduced and almost over.

Exactly.

I can't help but continuing to mull over the 2012 GAC, which exactly coincided with that year's 2D curves (extent, area) beginning to diverge from basically tied for lowest to way lower. I have read the objections about the GAC not being the main cause, but remain skeptical. It seems plausible to me that the worst thing for the ice this time of year (or at least in a couple weeks), now that the pack is fully mobile with plenty of warm water and air nearby, would be storms*. Yes, this is simplistic thinking and I'm no meteorologist, but on the other hand the "high pressure is bad" trope is no more sophisticated. Which is why I asked.

* Given a sufficient setup, which we seem to have this year as in 2012.

« Last Edit: July 21, 2019, 10:30:41 PM by petm »

Steerpike

  • New ice
  • Posts: 9
    • View Profile
  • Liked: 5
  • Likes Given: 10
Re: "Stupid" Questions :o
« Reply #2271 on: July 21, 2019, 10:34:42 PM »
I would imagine an upper air High would also lead to significant divergence (air descending and warming as it does), giving rise to higher surface temperatures, but this may be impeded by a surface temperature inversion due to the cold ice. However, I agree, as insolation is a month past its peak, a GAC would probably be more damaging - unless the High is part of a dipole, feeding in warm air from a heatwave on land.
“I come for sanctuary. I am a rebel. I am at your service as a dreamer and a man of action.”

bluice

  • Frazil ice
  • Posts: 108
    • View Profile
  • Liked: 28
  • Likes Given: 130
Re: "Stupid" Questions :o
« Reply #2272 on: July 21, 2019, 10:43:11 PM »
Although insolation is past it’s peak it is still high. I suppose high pressure with warm air mass in late July & storm later in August would be the weather to break records.
In PIOMAS we trust

uniquorn

  • Nilas ice
  • Posts: 1256
    • View Profile
  • Liked: 567
  • Likes Given: 110
Re: "Stupid" Questions :o
« Reply #2273 on: July 22, 2019, 12:10:55 AM »
Difficult to say what will be worse but clear weather is not best.

RoxTheGeologist

  • Frazil ice
  • Posts: 432
    • View Profile
  • Liked: 99
  • Likes Given: 81
Re: "Stupid" Questions :o
« Reply #2274 on: July 22, 2019, 12:18:20 AM »
It has been stated in the melting thread that there's a possibility of a huge high pressure ridge forming over the Arctic Ocean, and that if it happens it will be very bad for the ice.

But would a huge high pressure ridge be bad for ice retention, and why? Just because insolation is still high for a few more weeks? But wouldn't it also bring an end to the winds? Wouldn't big storms be worse?
BTW the same question you asked in the MST came to me the moment i was reading all the exited posts that, if it were mid june to mid july, were true, but people get used to keywords and key-events, often forgetting that the high season for a specific pattern is over or at least reduced and almost over.

Exactly.

I can't help but continuing to mull over the 2012 GAC, which exactly coincided with that year's 2D curves (extent, area) beginning to diverge from basically tied for lowest to way lower. I have read the objections about the GAC not being the main cause, but remain skeptical. It seems plausible to me that the worst thing for the ice this time of year (or at least in a couple weeks), now that the pack is fully mobile with plenty of warm water and air nearby, would be storms*. Yes, this is simplistic thinking and I'm no meteorologist, but on the other hand the "high pressure is bad" trope is no more sophisticated. Which is why I asked.

* Given a sufficient setup, which we seem to have this year as in 2012.



The earths outgoing energy (Wm2) on average is 239, so when the incoming radiation drops below that, you'd expect temperatures to drop and eventually for ice to form.
https://en.wikipedia.org/wiki/Earth's_energy_budget

It looks like the north pole drops below that sometime in late august. If you have less reflection from clouds in July it means that the ice and oceans are absorbing extra energy through insolation then they are losing. More energy = more ice melted.

In late July the energy absorbed is still as high as 60°N and almost as high as 30°N. That's pretty nice and toasty.

philopek

  • Frazil ice
  • Posts: 254
    • View Profile
    • Nutrition Secure Solutions
  • Liked: 89
  • Likes Given: 30
Re: "Stupid" Questions :o
« Reply #2275 on: July 22, 2019, 12:30:41 AM »
Great to see all the super replies on the topic about the impact of clear skies in august.

All the knowledge provided only proves how valid and good the question was.

A good day for many user's learning curve, at least for  mine

Villabolo

  • New ice
  • Posts: 46
    • View Profile
    • Global Warming Basics
  • Liked: 4
  • Likes Given: 14
Re: "Stupid" Questions :o
« Reply #2276 on: July 22, 2019, 01:03:46 AM »
I apologize if my question veers off of the discussion of this thread but I couldn't find anywhere else to post it. I don't know if it's a stupid to ask but...

Is it possible to produce bio char in a repurposed coal power-plant?

Michael Hauber

  • Grease ice
  • Posts: 836
    • View Profile
  • Liked: 46
  • Likes Given: 11
Re: "Stupid" Questions :o
« Reply #2277 on: July 22, 2019, 02:06:38 AM »
It has been stated in the melting thread that there's a possibility of a huge high pressure ridge forming over the Arctic Ocean, and that if it happens it will be very bad for the ice.

But would a huge high pressure ridge be bad for ice retention, and why? Just because insolation is still high for a few more weeks? But wouldn't it also bring an end to the winds? Wouldn't big storms be worse?

2007 - dominated by high pressure - record melt
2010/2011 - early high pressure domination, switching to more low pressure, early record melt rate stalling.  Later in 2011 due to later switch in 2011.
2012 - mix of high pressure and low pressure - record melt.
2013 - persistent low pressure - much less melt.

High pressure is more likely to work with Beaufort Gyre and move ice towards Atlantic, allows more solar heating, can only occur if upper polar vortext is broken down so allows more warmth imported in mid to upper levels, results in sinking air which warms that warmer mid/upper level air further and pushes it towards the surface.

Low pressure and winds mix heat around.  I think some low pressure as we saw in 2012 can be bad for the ice, but only if there is some heating as well, otherwise you get the 2013 result.

Climate change:  Prepare for the worst, hope for the best, expect the middle.

Sterks

  • Guest
Re: "Stupid" Questions :o
« Reply #2278 on: July 22, 2019, 08:29:32 AM »
It has been stated in the melting thread that there's a possibility of a huge high pressure ridge forming over the Arctic Ocean, and that if it happens it will be very bad for the ice.

But would a huge high pressure ridge be bad for ice retention, and why? Just because insolation is still high for a few more weeks? But wouldn't it also bring an end to the winds? Wouldn't big storms be worse?

2007 - dominated by high pressure - record melt
2010/2011 - early high pressure domination, switching to more low pressure, early record melt rate stalling.  Later in 2011 due to later switch in 2011.
2012 - mix of high pressure and low pressure - record melt.
2013 - persistent low pressure - much less melt.

High pressure is more likely to work with Beaufort Gyre and move ice towards Atlantic, allows more solar heating, can only occur if upper polar vortext is broken down so allows more warmth imported in mid to upper levels, results in sinking air which warms that warmer mid/upper level air further and pushes it towards the surface.

Low pressure and winds mix heat around.  I think some low pressure as we saw in 2012 can be bad for the ice, but only if there is some heating as well, otherwise you get the 2013 result.
+++

Sterks

  • Guest
Re: "Stupid" Questions :o
« Reply #2279 on: July 22, 2019, 09:25:28 AM »
It has been stated in the melting thread that there's a possibility of a huge high pressure ridge forming over the Arctic Ocean, and that if it happens it will be very bad for the ice.

But would a huge high pressure ridge be bad for ice retention, and why? Just because insolation is still high for a few more weeks? But wouldn't it also bring an end to the winds? Wouldn't big storms be worse?
A good explanation of what comes if only for a short period of time (not clear how gonna last)

https://www.americanwx.com/bb/topic/48618-arctic-sea-ice-extent-area-and-volume/?page=47&tab=comments#comment-5285900

binntho

  • Grease ice
  • Posts: 760
    • View Profile
  • Liked: 186
  • Likes Given: 52
Re: "Stupid" Questions :o
« Reply #2280 on: July 22, 2019, 09:57:29 AM »
Insolation falls down to equatorial levels in the first week of August, and keeps dropping like a stone towards the Equinox.

So I guess that clear skies during the next 10-15 days are bad for the ice.

Steerpike

  • New ice
  • Posts: 9
    • View Profile
  • Liked: 5
  • Likes Given: 10
Re: "Stupid" Questions :o
« Reply #2281 on: July 22, 2019, 09:58:11 AM »
It has been stated in the melting thread that there's a possibility of a huge high pressure ridge forming over the Arctic Ocean, and that if it happens it will be very bad for the ice.

But would a huge high pressure ridge be bad for ice retention, and why? Just because insolation is still high for a few more weeks? But wouldn't it also bring an end to the winds? Wouldn't big storms be worse?

2007 - dominated by high pressure - record melt
2010/2011 - early high pressure domination, switching to more low pressure, early record melt rate stalling.  Later in 2011 due to later switch in 2011.
2012 - mix of high pressure and low pressure - record melt.
2013 - persistent low pressure - much less melt.

High pressure is more likely to work with Beaufort Gyre and move ice towards Atlantic, allows more solar heating, can only occur if upper polar vortext is broken down so allows more warmth imported in mid to upper levels, results in sinking air which warms that warmer mid/upper level air further and pushes it towards the surface.

Low pressure and winds mix heat around.  I think some low pressure as we saw in 2012 can be bad for the ice, but only if there is some heating as well, otherwise you get the 2013 result.

Indeed. The key is how much preconditioning has occurred (and that includes both short term - i.e. broken and more dispersed ice from current year - and long term - i.e. thinner ice). A hurricane can pass over solid ice and do nothing, whereas a moderate storm passing over broken ice can kill it quickly due to dispersion into warmer water and mixing of surface with warmer and saltier water from depth.
“I come for sanctuary. I am a rebel. I am at your service as a dreamer and a man of action.”

deconstruct

  • New ice
  • Posts: 54
    • View Profile
  • Liked: 24
  • Likes Given: 15
Re: "Stupid" Questions :o
« Reply #2282 on: July 22, 2019, 12:32:45 PM »
The earths outgoing energy (Wm2) on average is 239, so when the incoming radiation drops below that, you'd expect temperatures to drop and eventually for ice to form.
https://en.wikipedia.org/wiki/Earth's_energy_budget
That is way to oversimplistic. The 239 Wm² of outgoing radiation is on average for the whole earth the whole year. But low latitude emit much more, than high latitudes on average, because it simply is warmer. When it is warmer, the outgoing radiation also increases, and vice versa. Then the 239 Wm² cover all from clouds to the surface. Then a lot of heat is transported through convection of air as well as through ocean currents and a lot of heat is buffered by the oceans, which will warm in summer and release that heat back in winter.

If ice would form anywhere simply because the average insolation on the ground would drop below 240 Watt/m², you would have a frozen Atlantic ocean down to 40° North, so the UK or New York woud see sea ice, which obviously isn't true.

Insolation in the Arctic even at the pole is till mid August still higher, than it is in winter e.g. in Los Angeles (33°N) or in North Carolina (35°N), where it is pretty warm even in winter.

Currently the insolation in the Arctic even at the pole is higher than on the Equator. So IMO a week of high pressure with a lot of sun will not be a good thing for the ice and I suppose that it would lead to massive melt in many areas. Additionaly, depending on the location of the high pressure system, that could also lead to a lot of ice being exported through Fram strait or just pushed out around Franz Josef Land into warmer Atlantic waters where it would melt out.

IMO the worst thing that could happen would be, that we would see 2 weeks with a lot of sunshine and insolation (while we are still near the insolation peak), which would thin the ice a lot more, and then a heavy storm in the second half of August which would slash that remaining ice.

Rich

  • Guest
Re: "Stupid" Questions :o
« Reply #2283 on: July 22, 2019, 02:18:49 PM »
I'm wondering if anyone would like to check my math here. I'm trying to calculate the total area N of 80N.

The area of a circle is pi * r squared.

For pi, I'm rounding to 3.142

I believe each degree corresponds to 60 nautical miles of 2,025 yards. I convert that to miles by dividing by 1,760 and then to km by multiplying by 1.609 before squaring.

I get 3.142 * ((60 * 10 * (2,025 / 1,760) * 1.609)) squared ~ 3.877M km2.

Phil.

  • Frazil ice
  • Posts: 314
    • View Profile
  • Liked: 20
  • Likes Given: 0
Re: "Stupid" Questions :o
« Reply #2284 on: July 22, 2019, 02:30:58 PM »
Rather than the Earth's average emission the value for ice at 0ºC would be more appropriate, which I make ~315W/m^2.  So as long as incoming exceeds that you'd expect melt, of course that depends on the reflectivity of the surface, melt ponds etc.

Phil.

  • Frazil ice
  • Posts: 314
    • View Profile
  • Liked: 20
  • Likes Given: 0
Re: "Stupid" Questions :o
« Reply #2285 on: July 22, 2019, 02:37:52 PM »
I'm wondering if anyone would like to check my math here. I'm trying to calculate the total area N of 80N.

The area of a circle is pi * r squared.

For pi, I'm rounding to 3.142

I believe each degree corresponds to 60 nautical miles of 2,025 yards. I convert that to miles by dividing by 1,760 and then to km by multiplying by 1.609 before squaring.

I get 3.142 * ((60 * 10 * (2,025 / 1,760) * 1.609)) squared ~ 3.877M km2.

It's a segment of a sphere not a circle so the area is given by {\displaystyle A=2\pi r^{2}(1-\cos \theta )}
where theta is 10º in this case.
Sorry equation didn't display correctly:
A=2*pi*r^2*(1-cos(theta))

sailor

  • New ice
  • Posts: 51
  • I avoid polynya
    • View Profile
    • www.atomarxviento.com
  • Liked: 22
  • Likes Given: 17
Re: "Stupid" Questions :o
« Reply #2286 on: July 22, 2019, 02:40:06 PM »
I'm wondering if anyone would like to check my math here. I'm trying to calculate the total area N of 80N.

The area of a circle is pi * r squared.

For pi, I'm rounding to 3.142

I believe each degree corresponds to 60 nautical miles of 2,025 yards. I convert that to miles by dividing by 1,760 and then to km by multiplying by 1.609 before squaring.

I get 3.142 * ((60 * 10 * (2,025 / 1,760) * 1.609)) squared ~ 3.877M km2.
It sounds about right.
The area above 80 N can be nicely approximated by "flat earth" assumption, I don't see the deviation in area with respect to the real curved surface to be a big issue in the angle is 10 degrees.
So I take 600 nmi = 1111 km
 A = pi * r2 = 3.14159 * 1111^2 km2
and I get the same result.
On the thin ice of modern life

binntho

  • Grease ice
  • Posts: 760
    • View Profile
  • Liked: 186
  • Likes Given: 52
Re: "Stupid" Questions :o
« Reply #2287 on: July 22, 2019, 02:51:46 PM »
3.877M km2.
Phil posted one of the many formulas for working this out, A=2*pi*r^2*(1-cos(theta)) where theta is 10 degrees and r = 6,371km.

So A = 2 * 3.14159265359 * 6371 * 6371 * (1 - 0.98480775301)
= 6.28318530718 * 40,589,641 * 0.01519224699
= 3,874,512.719038965

In other words, if the Earth were an exact sphere (which it isn't) the area north of 80 degrees is slightly more than 3.875 M km2 which isnt't all that far off your number Rich.

Which makes me wonder how the Arctic Ocean can be in excess of 14 M km2, I'd have thought they would be of similar size?

binntho

  • Grease ice
  • Posts: 760
    • View Profile
  • Liked: 186
  • Likes Given: 52
Re: "Stupid" Questions :o
« Reply #2288 on: July 22, 2019, 03:05:31 PM »
I think I'll have to caveat my last comment. The Central Arctic Basin holds a maximum of 4.4 million km2, and is (sizewise) not far from the north of 80 degrees area.

Arctic ice in total reaches, at maximum, some 15 million km2 and obviously covers a lot more than only the area north of 80 degrees.

Rich

  • Guest
Re: "Stupid" Questions :o
« Reply #2289 on: July 22, 2019, 03:26:00 PM »
 Thanks for the QA Binntho.

I'm thinking about analyzing the CAB by subdividing it into sections like a pizza or a clock.

If we divide into 12 sections of 30 degrees each with the pole at the center, we get ~ 320K km2 in each slice. 240 K km2 in the 80-85N zones, 80K km2 in the 85-90N zones.

gerontocrat

  • First-year ice
  • Posts: 5812
    • View Profile
  • Liked: 962
  • Likes Given: 18
Re: "Stupid" Questions :o
« Reply #2290 on: July 22, 2019, 04:18:02 PM »
I think I'll have to caveat my last comment. The Central Arctic Basin holds a maximum of 4.4 million km2, and is (sizewise) not far from the north of 80 degrees area.

Arctic ice in total reaches, at maximum, some 15 million km2 and obviously covers a lot more than only the area north of 80 degrees.

If you mean the Central Arctic Sea / Basin as defined by NSIDC it has an area of 3.2 million Km2 and is defined by North of 80 except that little slices are chopped off as its edges with the other seas are straight lines not following the 80 circle. It is also less than the area of 80+ North of 3.875 million Km2 because of a slice of land (North Greenland).

The CAB used by Wipneus in some of his stuff is 4.4 million km2, about the same as in the analyses by the late, lamented Cryosphere Today (RIP). I think it is basically the NSIDC Central Arctic Sea + Beaufort + CAA ??

I only ever use the NSIDC sea boundaries. I believe you can blame Meier and Stroeve who dreamt them up for their 2007 paper "Whither Arctic Seas?" for which they created the mask file still in use today (which I will crack one day tho I will have to learn a bit of Python).
_________________________________________________________-
C'mon, you people, less of the meta principles and big ideas and more basic data, like how big is the Arctic Ocean, how big are the individual seas compared with the land area of  Russia, Canada etc
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

RoxTheGeologist

  • Frazil ice
  • Posts: 432
    • View Profile
  • Liked: 99
  • Likes Given: 81
Re: "Stupid" Questions :o
« Reply #2291 on: July 22, 2019, 06:50:31 PM »
The earths outgoing energy (Wm2) on average is 239, so when the incoming radiation drops below that, you'd expect temperatures to drop and eventually for ice to form.
https://en.wikipedia.org/wiki/Earth's_energy_budget
That is way to oversimplistic. The 239 Wm² of outgoing radiation is on average for the whole earth the whole year. But low latitude emit much more, than high latitudes on average, because it simply is warmer. When it is warmer, the outgoing radiation also increases, and vice versa. Then the 239 Wm² cover all from clouds to the surface. Then a lot of heat is transported through convection of air as well as through ocean currents and a lot of heat is buffered by the oceans, which will warm in summer and release that heat back in winter.

If ice would form anywhere simply because the average insolation on the ground would drop below 240 Watt/m², you would have a frozen Atlantic ocean down to 40° North, so the UK or New York woud see sea ice, which obviously isn't true.

Insolation in the Arctic even at the pole is till mid August still higher, than it is in winter e.g. in Los Angeles (33°N) or in North Carolina (35°N), where it is pretty warm even in winter.

Currently the insolation in the Arctic even at the pole is higher than on the Equator. So IMO a week of high pressure with a lot of sun will not be a good thing for the ice and I suppose that it would lead to massive melt in many areas. Additionaly, depending on the location of the high pressure system, that could also lead to a lot of ice being exported through Fram strait or just pushed out around Franz Josef Land into warmer Atlantic waters where it would melt out.

IMO the worst thing that could happen would be, that we would see 2 weeks with a lot of sunshine and insolation (while we are still near the insolation peak), which would thin the ice a lot more, and then a heavy storm in the second half of August which would slash that remaining ice.


Here's the OLR for July, close to 225 - I did simplify to make the point that the incoming radiation is much higher than outgoing, so clear sky in July has a positive energy balance. It seems that the July OLR is pretty close to the earths average :).

http://cimss.ssec.wisc.edu/wxwise/homerbe.html



philopek

  • Frazil ice
  • Posts: 254
    • View Profile
    • Nutrition Secure Solutions
  • Liked: 89
  • Likes Given: 30
Re: "Stupid" Questions :o
« Reply #2292 on: July 22, 2019, 07:51:23 PM »
Here's the OLR for July, close to 225 - I did simplify to make the point that the incoming radiation is much higher than outgoing, so clear sky in July has a positive energy balance. It seems that the July OLR is pretty close to the earths average :).


Thanks, great contribution.

I think there was quite common sense that in July this is as you just proved. the question was more when this will change and how fast.

Some mentioned several weeks, I'm in the ballpark of 2 weeks, +/- something and others asked about 2-3 days out.

The latter is now clearly answered thanks to the information you just posted.

oren

  • Young ice
  • Posts: 4180
    • View Profile
  • Liked: 679
  • Likes Given: 1191
Re: "Stupid" Questions :o
« Reply #2293 on: July 22, 2019, 10:40:15 PM »
Thanks for the QA Binntho.

I'm thinking about analyzing the CAB by subdividing it into sections like a pizza or a clock.

If we divide into 12 sections of 30 degrees each with the pole at the center, we get ~ 320K km2 in each slice. 240 K km2 in the 80-85N zones, 80K km2 in the 85-90N zones.
Unless you can analyze the gridded data files for area extent and volume like Wipneus does, the analysis will not get you far.
If you can, then I would suggest a different slicing, according to geography and sea ice behavior.
I think of four parts to the CAB:
Pacific CAB - facing the Beaufort and Chukchi. Opens early during Pacification years.
Siberian CAB - facing the ESS and Laptev. Opens early during big Laptev bite and Siberian heateave years.
Atlantic CAB - facing the Kara and Barents and the Fram/Greenland Sea, thinner than the others. Opens early during Atlantification years, sometimes even during winter and spring.
Core CAB - facing the eastern CAA and north Greenland, and including the Pole. Thickest ice. Rarely opens at all except at the margins.
I once drew a map with rough demarcations. I will try to dig it up.

Rich

  • Guest
Re: "Stupid" Questions :o
« Reply #2294 on: July 22, 2019, 11:47:03 PM »
Thanks for the input Oren. You really deserve some kind of recognition for being an all-around great contributor here at ASIF. In sports, they have a positive term for someone who contributed to the overall chemistry of a team and makes it a winner. They call that person the "glue guy". As in, they provide the glue that holds things together. I have you pegged as the ASIF glue guy.

I don't think I have any lofty aspirations of being able to reconcile any analysis empirically with what others are doing. As a devoted minimalist, there are limits to what one can accomplish w/o a PC.

What I am interested in doing is understanding the monolith known as the CAB and subdividing it to better understand it.

The divisions you suggested seem very logical.

I'll give you an example of what I was imagining in the way of analysis....

Let's say we use the clock analogy. 6 and 12 o'clock separate east from west. 6 o'clock is at W side of Ellesmere and 12 is the islands separating Laptev from Kara.

One o'clock would be pointing at the Kara. At this point the Kara is interesting and different from other parts of the larger Atlantic CAB in that the SST's are higher in the vicinity of the CAB. That might make a case for projecting higher losses in the rest of the season than the 2 o' clock slice (Barents) or 3 o'clock slice (Greenland Sea / Fram).

As we look to the future, there is obviously a great deal of interest here in discussing things associated with ice minima and that becomes more and more about the CAB. I think it benefits the forum to cultivate more intra-CAB understanding. The giant NSIDC single bucket doesn't cut it IMO.

Anyway.. thanks for your input. It's always welcome.

Shared Humanity

  • Young ice
  • Posts: 3816
    • View Profile
  • Liked: 318
  • Likes Given: 37
Re: "Stupid" Questions :o
« Reply #2295 on: July 23, 2019, 01:01:09 AM »
Thanks for the QA Binntho.

I'm thinking about analyzing the CAB by subdividing it into sections like a pizza or a clock.

If we divide into 12 sections of 30 degrees each with the pole at the center, we get ~ 320K km2 in each slice. 240 K km2 in the 80-85N zones, 80K km2 in the 85-90N zones.

Better to evaluate the CAB based on bathymetry.

Rich

  • Guest
Re: "Stupid" Questions :o
« Reply #2296 on: July 23, 2019, 02:36:07 AM »

Better to evaluate the CAB based on bathymetry.

Do you think there's enough contrast there?

On the Atlantic side, there are shallow ridges that extend to ~ 83N and immediately adjacent to the CAA it's also shallow, but not necessarily too relevant.

Beyond that it's deep and deeper.... a nice seque to my next stupid question:

Does it make a difference if the water is 500m deep vs 2,000m deep in terms of impact on ice melt?

oren

  • Young ice
  • Posts: 4180
    • View Profile
  • Liked: 679
  • Likes Given: 1191
Re: "Stupid" Questions :o
« Reply #2297 on: July 23, 2019, 03:36:50 AM »
What I am interested in doing is understanding the monolith known as the CAB and subdividing it to better understand it.

The divisions you suggested seem very logical.

I'll give you an example of what I was imagining in the way of analysis....
Thanks for the feedback.
I managed to find the crude map I was referring to, and the post from last year in which I explained the logic behind it. Looking back on it, the Pacific CAB sector should probably be a bit thicker.
The big challenge is once someone adopts this map, there is not much one can do in terms of quantitative analysis (such as area per sub-region, volume per sub-region), unless one can do the number-crunching of taking the gridded data files and filtering them by sub-region according to the new demarcations. That I have not been able to do, though it's theoretically possible (I can program crudely, have a PC, and don't dislike number crunching). An attention deficit issue coupled with lack of time I suspect.

FishOutofWater

  • Grease ice
  • Posts: 741
    • View Profile
  • Liked: 270
  • Likes Given: 108
Re: "Stupid" Questions :o
« Reply #2298 on: July 23, 2019, 04:18:38 AM »
Here's a more informative way to look at the central Arctic - a sea surface height map. There are strong SSH gradients across the central Arctic indicating strong flow of water and ice. This year the transpolar drift has been strong and has run right through the central Arctic. The areas in the central Arctic basin with high SSH store fresh water and the areas with low SSH are dominated by cold salty water.

Paddy

  • Grease ice
  • Posts: 549
    • View Profile
  • Liked: 19
  • Likes Given: 29
Re: "Stupid" Questions :o
« Reply #2299 on: July 23, 2019, 12:41:06 PM »
A year or two back, someone on this forum was tracking the number of days which were at a record low per year. Is anyone still tracking this at the moment?