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Messages - Michael Hauber

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1
Arctic sea ice / Re: The 2019 melting season
« on: June 13, 2019, 02:09:20 AM »


Strong melting conditions mostly on the Russian side, but also a fairly significant incursion of heat north of Greenland, but not nearly as extensive an area.  But a large area of cooler conditions with minimal surface melt.

Forecasts suggest the cool zone will shrink to a thin area on the American side.  Cooler conditions will continue and maybe expand on the Atlantic side, but with a great deal of wind/storminess. 

2
Arctic sea ice / Re: The 2019 melting season
« on: June 12, 2019, 11:12:47 AM »
Thats a pretty serious cyclone forecast at about 72 hours, bottoming out at 966 by GFS and 972 on EC, and a fairly large circulation.  With the ongoing hot weather it looks like we are already on the strongest start to melt season in Laptev sector, or at least close to it.  So adding this to the mix could be rather significant.  I don't think the ice is as vulnerable to flash melting as it was in GAC 2012, at least in Laptev and Arctic Basin.  Barents and Kara would be more vulnerable.  Not sure what (if anything) the islands will do to reduce impact - blocking waves etc.

3
Arctic sea ice / Re: The 2019 melting season
« on: June 11, 2019, 08:54:27 AM »
A tale of two Arctics.  Warm air has pushed into Siberian and Laptev sectors in a big way with serious surface melting.  Beyond that the Arctic is mild with minimal surface melting.  Beaufort amazes me with many large floes and little to no small floes - Little visible sign of melting but plenty of open water.

Forecasts show a strong temperature contrast with the coolest air still at -8C at 850HP according to GFS, and the warmest air above +12C.  Definitely one of the larger temperature contrasts I've seen.

4
Not as good a start as 2012, but not that far behind, and 7 years of global warming since then, so I vote 3-3.5 to roughly equal 2012.  I think I've been voting most years for beating or equalling 2012 so.....

5
Arctic sea ice / Re: The 2019 melting season
« on: June 08, 2019, 06:39:28 AM »
Channel 3-6-7 has no problem seeing wet surfaces on the thinnest of ice.  Have a look at the url=https://worldview.earthdata.nasa.gov/?p=arctic&l=MODIS_Terra_CorrectedReflectance_Bands367,VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2019-06-07-T00%3A00%3A00Z&z=3&v=-2661509.2245357623,1060293.7737951968,-1262725.2245357623,1710533.7737951968]Bering Strait[/url] at the moment.  Very thin ice, clearly on its last legs and fractured into individual floes to small to be spotted individually is still clearly red and wet on the surface. 

I do also look at Microwave imagery for evidence of melt ponds, but that is much less sensitive and picks up only strong surface melt ponds.  Too early to spot anything this year or other years as at this date using this method, and from past experience thick ice can hold deeper melt ponds that show up much better on this method, with occasionally fast ice nearly disappearing from sensor view due to the amount of melt water it can hold on top.  In contrast I have very rarely spotted melt ponds  using Jaxa near the edge of the ice field, and its usually only early in the season that melt ponds can be seen in such imagery as the ponds drain later in the season.

6
Arctic sea ice / Re: The 2019 melting season
« on: June 07, 2019, 09:54:22 PM »
I think one of the things slowing down surface melt is that the high pressure is shallow and not reflected in the uppers.  So plenty of sunshine, but no warming from forced air decent from an upper ridge.  Delayes surface melting means lots of the sunshine is bouncing of shiny ice.  Also a decent portion of the Arctic is covered by two low pressure systems.  These low pressure systems have stronger upper signatures and weaker surface signatures.  So less surface winds, dispersion, ekmann pumping.  But stronger uppers means more cloud and reflecting sunshine away from the ice.  The Siberian low seems to be a bit cut off and not drawing in any substantial warm air, whereas the Laptev low is connected to a strong mass of warm air over Russia and pulling in quite a lot of warm air into Laptev, where substantial surface melt is visible.

7
Arctic sea ice / Re: The 2019 melting season
« on: June 07, 2019, 01:39:40 AM »
Here is a tentative ranking of subjective whiteness from whitest to bluest/greenest for June 5th from 2000 to 2019, based on https://go.nasa.gov/2WWvSva these Worldview settings.

1st (lightest): 2004
2nd: 2000
3rd: 2003
4th: 2009
5th: 2006
6th: 2018
7th: 2002
8th: 2008
9th: 2014
10th: 2013
11th: 2001
12th: 2017
13th: 2010
14th: 2005
15th: 2015
16th: 2011
17th: 2019
18th: 2007
19th: 2016
20th (darkest): 2012

I agree that 2019 is behind 2016 and 2012, based on what I've looked at with 3-6-7 channels (haven't looked at 07).  Current forecasts cook some parts of the Arctic towards the edge, with large parts and much of the core staying on the cooler side.  One run of GFS forecast a serious cooking over a large portion of the Arctic, but most other forecasts don't.

Current forecasts take us to mid June, with melt momentum above average at best, and certainly not exceptional enough to be a serious challenge to the top contenders.  This applies to surface melt only, and not whatever is going on below the surface, although surface temps are going to influence bottom melt.  And as the world has warmed up since 2012 and 2007 there is much more scope to catch up, without a fast start on the surface.

EC 850hp 96 hours valid 12z Jun 10.  Selected as one of the coolest dates in the current forecast.


8
Arctic sea ice / Re: Do we make too much of 2012 ?
« on: June 07, 2019, 01:19:16 AM »
But do we make too much of 2016, because of ENSO?
Some people do.  But that's what happens in pretty much any discussion.

No, we just make graphs like this one:
Good graph.

We don't make too much of anything. We just compare, compare, compare, and try to make sense of things.
And a good job.


9
Arctic sea ice / Re: The 2019 melting season
« on: June 06, 2019, 12:54:29 AM »
One thing I notice about the forecast is that there is a mix of strong warm air incursions, and a low pressure system swirling a substantial cool and cloudy pool around the arctic.  I'd say that makes the forecast only moderately bad, maybe even average compared to recent years.  Unless that low spins up enough to cause significant stirring/divergence of the ice, but generally it seems to stay week enough to be good for the ice and not destructive.

A point on the dipole.  There does seem to be a pattern resembling a dipole, but it doesn't seem to be achieving a lot.  Air near Bering region isn't that warm, so there isn't a lot of heat being sucked in by the dipole.  A lot more heat being sucked in from middle Russia by the warm front sector of low pressure towards Laptev.  I suspect that el nino actually helps arctic ice a little.  With an el nino zonal variation in the north Pacific weakens and warm air stays more in the tropics.  With La Nina more likely to have high pressure in NE, and low pressure in NW drawing warm air towards the Bering region.  Then if there is a dipole it will be sucking on much warmer air.

10
Arctic sea ice / Re: Do we make too much of 2012 ?
« on: June 06, 2019, 12:38:02 AM »
Maybe we make too much of Arctic ice.  Look at the global temperature trend, that's what matters.

Otherwise the Arctic ice is an interesting aspect of AGW, and when we beat 2012 an interesting question in its own sake.

11
Arctic sea ice / Re: Global sea ice area and extent data
« on: June 05, 2019, 01:38:52 AM »

I wonder what, in a purely objective world, with no emotional commitment to hypotheses of warming, whether a scientific ( or indeed lay ) observer would make of such a trend.

No one is truly objective with no commitment to a particular hypothesis.  But I can at least claim to have been accused of being a denier in this forum on multiple occasions, whatever that may be worth in your opinion.

My opinion on the overall global sea ice trend is that it is pretty much what you expect in a world that is warming at a rate close to what was predicted some 40 years ago.  If you want to look at questions of whether the world is warming or not look at the global temperature trend, and not sea ice, which reflects temperature over a limited portion of the globe, and is also influenced by winds etc.  Its not a particularly important stat, and more interesting might be combined sea ice + snow cover, which then relates to global albedo, and one of several important feedbacks on global temperature change.  But important or not it is still interesting to look at from time to time.

12
Arctic sea ice / Re: The 2019 melting season
« on: June 05, 2019, 01:17:46 AM »
June 4 Channel 3-6-7.  Significant amount of red showing in Laptev area.  I'd say 2012, 2015 and 2016 all have more red (Arctic wide) as at June 4 than 2019.  Hard to be sure about 2012 due to cloud cover, but given the events of that year I'm more bullish guessing on red below the clouds for that year.  Red reflects surface melting.


13
Arctic sea ice / Re: The 2019 melting season
« on: June 03, 2019, 12:37:03 AM »
I like channel 3-6-7 for diagnosing surface melt conditions.  Current View shows that although the Beaufort has low ice, the surface is quite cool with pretty much no surface melting.  Not much surface melting visible elsewhere in the Arctic, maybe a slight hint in Laptev/Siberian sector.  It wouldn't suprise me if Kara is melting under all that cloud.

In contrast 2012 had significant surface melting visible on the Pacific edge at this date.  By the 6th June surface melt had expanded to much of the Russian half of the Arctic. 

My reading of the current forecast is that while there is a decent high pressure in place, there isn't a whole lot of flow into/out of the Arctic, and the uppers are on the cool side.  Current situation is comparable to 2012, and certainly not significantly worse.  Surprising to me that we are 7 years on and yet to break the 2012 record.  Weather needs to get a hurry on or the strong melt conditions in early to mid June will open up a substantial lead in surface melt for 2012 in my opinion.

14
Arctic sea ice / Re: The 2019 melting season
« on: May 24, 2019, 01:32:41 AM »
For those interested in what happened in the Beaufort, back in 2016 (so as to compare to this year's siutation), I wrote about it extensively on the ASIB. Here's a blog post from May 21st, with links to previous blog posts in the first paragraph.

The maps look very similar, so much so that one would be tempted to think there is something causing the ice to stay glued to the coast, all the way up to Utqiaġvik. But there's no "Chukchi polynya" now, with open water all the way to the Pacific and far into the Chukchi, meaning there is less ice to be blown back towards the coast, should the winds turn.

And the winds are another similarity. Both the weather forecast back then and the one this year show a change in the set-up that caused the early Beaufort opening, around the same time. However, this year there may be a return to that set-up next week.

So, wondering if there will be open water all along the Alaskan-Canadian coast before July this year...

My guess there are two factors behind this 'ice bridge'.  First there seems to be more fast ice on the coast - presumably the sea bed is shallow and/or perhaps currents favour colder water below the ice.  Second I suspect the beaufort gyre and shape of the coast line combine.  Ice I think tends to move away from the coast towards Chukchi and towards CAA, but towards the coast near this ice bridge.  As soon as temps warm enough that ice can't form these two areas become ice free as ice moves away from the coast, but the ice bridge area needs temps to warm enough that substantial ice in the Beaufort at large is melted and there is no longer enough ice to move towards the coast.



(using paint so hard to get a nice curve to better illustrate the ice flow)

15
Arctic sea ice / Re: The 2019 melting season
« on: May 23, 2019, 12:05:05 AM »
Here is a recent photo of sediment.



From Cat 6 blog.

Of course not all sediment will look exactly the same.

16
Consequences / Re: World of 2030
« on: April 29, 2019, 06:20:20 AM »
Global temperatures about 0.2 degrees C warmer than now.  As the warming is not uniform some areas maybe be 0.4 warmer than now.

Sea level rises to be about 3cm higher than now.  Even under the most alarmist predictions of ice sheet collapse unlikely to be more than 5cm.

Frequency of hurricanes etc to be statistically indistinguishable from now.

Climate change deniers who predicted a reversal of the steady warming trend in the 00s, then the 10s, will ignore the failure of cooling to arrive in the 20s and predict it for the 30s.

Catastrophists who predicted a major acceleration of the warming trend in the 00s, then the 10s will ignore the failure of catastrophe to arrive in the 20s and predict it for the 30s.

Food security?  Climate change will steadily erode our ability to supply food.  The worlds population will steadily grow.  Science will steadily improve our ability to supply food.  At some stage food production might fall short of demand and cause serious problems for society.  Hard to predict whether it will be this decade (how much will advances in science, that is learning to do stuff we don't know how to do know help us out?), but considering the number of golf courses, non productive ornamental gardens and protected wilderness parks on the planet I think we might have a way to go yet.  Of course when these are being converted to agriculture because we need to eat its probably too late to avoid the food crisis.

17
Arctic sea ice / Re: Are 3 dimensions better than 2?
« on: April 05, 2019, 05:56:51 AM »
There are two parts to the Arctic.  One part where there is too much heat during the year for ice to survive the melting season, and another part where there is not enough heat during the year to melt the ice.  Extent is the best measure of the shrinking of the zone in which ice can survive, and best measure of the long term trend in reducing the ice, and best predictor of when we will go ice free.  Those who were extrapolating volume/thickness loss around 10 years ago were predicting ice free by about now.  Those who were extrapolating extent predicted that we wouldn't be.  Looks to me like the predictions based on extent were better.

Thickness remembers recent conditions, and encodes information on how warm that part of the Arctic is.  If thickness is very low, that suggests recent temperatures have been warmer, and it is more likely that the ice won't last this specific season.  Thickness is the most important measure for predicting short term changes in ice extent and whether ice will survive the coming melt season.

18
Consequences / Re: Weird Weather and anecdotal stories about climate change
« on: November 29, 2018, 02:22:38 AM »
The Sydney floods (plus gales and hail and fairly cold conditions, none of which were exceptional but still unusual), Intense heat in Cairns, serious bushfires, dust storms yesterday, dust storms mentioned a week or so ago in this thread.  All related to the same pattern of an unusual sequence of low pressure systems through Australia and out into the Pacific, which may be related to Southern Polar Vortex issues.

19
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 29, 2018, 02:14:07 AM »
Trivia break motivated by some recent controversy:

The specific heat of rock/soil is significant.  For granite it is about 20% of that of water by weight.  But granite is 2.75 x the density of water, so over 50% of the heat capacity of water.  The soil and rock below us cannot absorb as much water as the ocean, but it still can absorb quite a lot.  The importance of the ocean's ability to absorb heat is not just its specific heat capacity, but the rate that the heat can mix down below the surface (and then mix back up again).  In contrast the soil and rock pretty much does not mix up or down except in very unusual circumstances, and heat can only move in or out through conduction, and not be convection.

Heat absorbed by the ground can have quite a significant impact on weather as the Brown Ocean effect

20
Antarctica / SH Polar Vortex
« on: November 23, 2018, 06:34:28 AM »
Also posted in weird weather thread in consequences.

Furthermore there is a remarkable string of strong low pressure systems belting across Australia and well into the Pacific.  Got some members of the weatherzone forum scratching our heads not sure what to make of it.  The pattern might have implications for ENSO, as I think its part of why a significant WWB is forecast to commence shortly.

I've been doing some hunting around to see if I can explain it as some sort of polar vortex variation.  Due to this forum I know more about the northern polar vortex than the southern which impacts on my weather.  Of course Antarctica hasn't had no real trend towards reducing sea ice, but has had a couple years of fairly low values.  Start of a similar change in SH to what has happened in NH?  Maybe some connection to changes in the Ozone hole....

Does anyone follow the SH polar vortex much and know if anything is going on that might explain part of this weird weather?

21
Consequences / Re: Weird Weather and anecdotal stories about climate change
« on: November 23, 2018, 06:31:22 AM »
Australia Dust Storm: Health Warning As Skies Change Colour 
https://www.bbc.com/news/world-australia-46298309

A giant dust storm has blanketed communities across south-east Australia, turning skies orange and raising concerns about air quality.

Authorities issued a public health alert for Sydney on Thursday as the 500km-wide (310 miles) dust band began to reach the city.

... The problem has been exacerbated by a drought that has affected the entire state of NSW since August, according to Australia's Bureau of Meteorology.



Dust storms occur from time to time in Australia.  But normally in late winter, and not late Spring.  (edit I did a bit of googling and contrary to my impression Nov is peak dust season in Sydney)  Furthermore there is a remarkable string of strong low pressure systems belting across Australia and well into the Pacific.  Got some members of the weatherzone forum scratching our heads not sure what to make of it.  The pattern might have implications for ENSO, as I think its part of why a significant WWB is forecast to commence shortly.

I've been doing some hunting around to see if I can explain it as some sort of polar vortex variation.  Due to this forum I know more about the northern polar vortex than the southern which impacts on my weather.  Of course Antarctica hasn't had no real trend towards reducing sea ice, but has had a couple years of fairly low values.  Start of a similar change in SH to what has happened in NH?  Maybe some connection to changes in the Ozone hole....

22
Arctic sea ice / Re: The 2018/2019 freezing season
« on: November 16, 2018, 06:38:10 AM »
A guy at NASA just came out with a report saying we will have unusually cold weather starting in about 6 weeks because of persistent lack of sunspot activity. This low has been predicted for years and we’ll see how it affects earth temperatures. Who know but maybe we will get heavy freezing this year over the arctic and see a much needed recovery to ice such as we haven’t seen for decades.

If there is to be such a recovery we need two things: very strong and persistent ice formation this freezing season and cool 2019 with slow ice melt to preserve ice going into next year’s freeze.

Sorry for the late response but I've been a bit bored with Arctic Ice lately.  Google for 'NASA cold weather satellite' finds a few media articles in the last few days.  The daily mail makes this claim and is nice enough to link a source.  The prediction was made in September and here is the key quote:

Quote
“We see a cooling trend,” says Martin Mlynczak of NASA’s Langley Research Center. “High above Earth’s surface, near the edge of space, our atmosphere is losing heat energy. If current trends continue, it could soon set a Space Age record for cold.”

They refer to the thermosphere - which starts about 80km above the surface.  Interesting but probably not at all relevant to surface conditions.

23
Arctic sea ice / Re: The 2018 melting season
« on: September 21, 2018, 01:59:17 AM »

If you like the cold, go to Central Canada North of 60,
If you want to stay warm, go to Central Siberia as far north as you like.


Or If you like it warm go to Hawaii.  If you like the cold go to Central Siberia.  But stay away from North Central Canada as no one could possibly like it that cold lol. 

24
Arctic sea ice / Re: The 2018 melting season
« on: September 13, 2018, 03:31:24 AM »
I've had a look at the area I thought may have been new ice a few days ago.  Hard to tell due to cloudiness, but it seems that the area filled with ice over the last few days, but it is large floes clearly not newly formed, and there is no sign of fresh thin ice between the floes.  If any new ice had formed I think it melted again.

Having a bit more of a hunt around today I'm reasonably confident that I've found a large crack north of Ellesmere Island that has partially filled with freshly frozen new ice.  here.

Freezing season has begun, although I'd say there is still far more melting than freezing at this moment.

25
Consequences / Re: Hansen et al paper: 3+ meters SLR by 2100
« on: September 12, 2018, 03:32:57 AM »


Perhaps the authors ignored the fact that due to the fingerprint effect a collapse of the WAIS would have very little impact on sea level change in the Mediterranean (see the attached image).

Your image shows that sea level change in the Mediterranean is a little above the global average.

I guess there is a reason I almost never look at these threads lol.

26
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: September 10, 2018, 02:45:13 AM »

Early days yet, Oren -  Getting Excel to change the ranges to sum automatically as the date changes is the one trick I have not yet cracked. (Using the date to change everything else has been pretty straightforward). Maybe my index goes into cold storage until the end of the year.



Put dates in column a, values in column b, first date in c1, last date in d1.  Formula: sumifs(b:b,a:a,">=" & c1,"<=" & d1) will add up everything between those dates.  Just watch for potential problems such as converting 8/2/2018 from 8th Feb to 2nd Aug.

27
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: September 08, 2018, 12:52:46 AM »
On the longer term trends, tamino has a couple interesting post.  In 2015 he find evidence of a statistically significant change in trend over the last 10 years.  In 2017 he doesn't.  I think its borderline.  I think claims of a genuine recovery or halt of ice melt in the last 10 years are nonsense.  But claims that things may have slowed down (perhaps following a Gompertz curve) are reasonable and cannot be easily dismissed as noise.  I'd suggest that the long term linear trend is probably the best description of what is happening, and the recent slow down is an interesting talking point.

28
Arctic sea ice / Re: The 2018 melting season
« on: September 06, 2018, 01:38:20 AM »
Can't pick anything that looks like fresh ice where the Russian maps says.  But further east.  Maybe new ice?  To the right of the big island.  Hazy stuff that wasn't there yesterday, and if you put channel 3-6-7 it is redish, and not white like the clouds.

29
Arctic sea ice / Re: The 2018 melting season
« on: September 04, 2018, 11:33:26 PM »
Not sure if this is the correct thread; forgive me if it is not!

What happened to the predictions of a GAC from the last week of so?

There is still a pretty decent cyclone going on around Laptev/Barents.  Not far off the intensity forecast a while back.  Pretty large system getting up towards the GAC 2012 size, but a fair gap in intensity.

The forecast Friv and I commented about just a day or so ago of a huge heat influx has moderated.  The forecast had a perfect alignment of strong high and low plunging a strong warm front in between directly into the Arctic.  The alignment has shifted a bit and the warm front now strikes a fairly glancing blow.  Until the next model run....

30
Arctic sea ice / Re: The 2018 melting season
« on: September 04, 2018, 03:13:38 AM »
The current GFS forecast towards the end of the 7 day period is quite spectacular in the ESS direction.  Could give the ice there a real smash if it comes off, but reliability of stuff at 5 days + and all that.....

Not much prospects of further melt from above for this season on the Atlantic side though.

31
Arctic sea ice / Re: The 2018 melting season
« on: August 29, 2018, 11:01:54 PM »

I don't think it is fair to say this year was GAC-less, the June event was about as impressive as 2012, it just happened far earlier in the melt season.

The June event was close when considering minimum pressure.  Not very close when considering size of circulation, or duration.

32
Arctic sea ice / Re: The 2018 melting season
« on: August 29, 2018, 12:02:07 AM »
MODIS 3-6-7 channel shows nearly total cloud cover of the Arctic, but what shows in between the clouds suggests that the surface is mostly frozen and that the surface melting season is mostly over.

A thought on the current cyclone, forecast to continue for the forseeable future.  SSTs are close to their seasonal max now, mixing and winds will cool them faster (but clouds keep the heat in).  But mixing may also push some of the heat below the surface to impact the start of the freeze season.  In contrast if the heat is left undisturbed near the surface in calm conditions it might be lost much quicker as Arctic night falls.  Ekman pumping will produce upwelling mostly in the central ice pack and presumably this will need to be balanced by downwelling somewhere in the Arctic fringes which might also push heat below the surface.

33
Arctic sea ice / Re: The 2018 melting season
« on: August 28, 2018, 01:16:59 AM »
Forecasts have a decent low pressure system taking over the Arctic, and air temperatures cooling.  A substantial, but not yet dominant area of -8 degrees at 850hp is now evident, which is roughly the temp at which surface melt stops.  I'd agree that the surface melt season is ending, which is fairly normal for this time of year, and we will see how much bottom melt continues with the help of some stirring and mixing from the low pressure system.  While not the most intense low pressure system, it does look to be quite a decent size.

p.s. just because I've mentioned the melt season ending doesn't mean I'm lobbying for the creation of a freeze season thread.  Although on that topic I've always though using calendar dates might head off the discussions of when the new melting or freezing season thread should start.  So instead of 2018/2019 freezing season have Oct 2018 to Apr 2019 general discussion or similar.

34
Arctic sea ice / Re: The 2018 melting season
« on: August 23, 2018, 01:30:18 AM »

In very short.  YES solar fluctuation does have an impact.  NO, that impact is not significant, but it is there and it is measurable.

Bordering on overly pedantic quibbling over definitions, and hopefully not crossing the line: I'd say anything there and measurable is significant.  For instance Collins dictionary definition

Quote
A significant amount or effect is large enough to be important or affect a situation to a noticeable degree.

Perhaps it depends on context, if you are trying to carefully analyse climate and build a model of everything going on then solar input is big enough that it should be included in the model (and  has been in at least some that I know of), and is therefore significant.  If you want to explain what is currently happening with climate to a layman who doesn't want to get bogged down in all the details than solar influence is small enough to be ignored and so not significant.

edit:  And a big issue with solar is possible regional changes brought about by circulation changes.  For instance part of the little ice age issue is that the cooling was strongest in regions not far from the Arctic, tied into changes to Atlantic Oscillation that may be linked to solar activity.  Quick google search finds this paper.  It is possible that low solar activity may lead to reductions in sea ice due to regional cooling in Europe etc balanced partly by regional warming in Arctic.

35
Arctic sea ice / Re: The 2018 melting season
« on: August 21, 2018, 01:40:22 AM »

How? It's in a distorted cylinder projection, doesn't go above 80ºN and is unreadable/unreliable there, plus it would have to be cut down to comparable ice covers which isn't practical without having the data in polar stereographic projection. Are the grid cells really of adequate resolution for the Arctic seas and islands -- I can barely make out Greenland.

[/quote]

How?  By opening your eyes and having a look.  It might not be as pretty or as easy to read as the newer charts, but the comparison is still very obvious that 2007 had a lot more warm ocean surface than this year.  Stands to reason as 2007 started with substantial amounts of thick multi-year ice, this year followed on from the warmest winter ever, and the multi-year ice basically gone.  But conditions in 2007 melted more ice than the conditions this year.

36
Arctic sea ice / Re: The 2018 melting season
« on: August 20, 2018, 11:13:31 PM »
SSTs look quite tame to me.  Compare current to 2007

In 2007 the warm ocean seemed to retard freeze for a few weeks with -ve anomalies on area dropping quite a lot (nearly 1m sq km from memory) in the few weeks after minimum.  After that freeze went rapidly and made up most of the lost ground within a few more weeks.

37
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: August 17, 2018, 11:22:17 PM »
Putting out the data on a daily basis is interesting, and despite the odd offhand comments to the contrary, most people seem to feel it has value.

But now as the season comes to an end, the question the data asks me is - "what was the story this melting season?" Of course the story ain't over yet but using graphs I would like to tell - as I see it - the story so far. I see it as a tale of two ends - the Pacific and the Atlantic, and may take some time as I look through the data.

At the beginning I thought(as did many others?) it was going to be all about the Pacific end. NOAA / NASA said it was that end that had the highest temperature anomalies (for several years), and low and behold, the Bering Sea Ice collapsed in front of our eyes.

I think a lot of people did expect big things on the Pacific side.  One thing though is that PIOMAS data at end of May showed that Siberia/Laptev ice was about the thickest of any recent years, with Beaufort being more typical and ice towards Greenland being on the thin side.  In some ways I thought there was potential for an all or nothing year this year - a savage melt season would have still taken out the thicker ice towards Russia, and attacked the thinner ice towards Greenland.  But an average melt season, or possibly poor melt season with slow start and stronger melt weather in August, allowed lots of this thicker ice to survive (so far).

38
Arctic sea ice / Re: The 2018 melting season
« on: August 09, 2018, 10:58:12 PM »
Seems that the big high pressure dome over the Laptev side of the Arctic is now starting to wind down.  No sign of massive ice loss as predicted by some of the more exciteable posters in this thread.  Models seem to want to build a significant low so we'll see what the heat and stir method can achieve.  I do think the ice in that area is on the strong side of what can be expected in this age of ice everywhere weaker, and the results might be similar to the recent Beaufort plunge - moving up through the pack a bit, but by no means leaving it in the dust.  We are getting into the shoulder season with strong but definitely declining solar input so the slow down due to cloudiness won't be as significant as for low pressure systems earlier in this season.

39
But this is OT as to the CAB surface going 'black' in the winter due to climate change.

True, but my point is that people are proclaiming Truth when it isn't even yet clear they are working with a viable Theory.

I'd like to hear suggested mechanisms, not obeyance to the Great Modelling Gods.

Strawman.  Models are not truth, no one has claimed that they are.

I'd say anyone who think that Arctic ice can disappear this century during winter lacks a viable theory and the challenge is to come up with a better method than the models of predicting future sea ice conditions.

40

I'm just strongly opposed to using current models to project "centuries" given that we can't really claim to even know what's going to happen with the seasonally ice free arctic in the decades after. And as a result, how could the models do any better?

Multi-century model projections are obviously problematic.  Is there a better alternative?  (I don't think so)  Or do we just avoid talking about the issue altogether?

41

Yes, of course, if it remains at -20°C and that the AML survives.

There is evidence that you start to get 1000m convection cells forming when the AML breaks down, say because of the lack of summer ice, and that would certainly cause enough heat to be transported to the cloudy dark rainy Arctic to keep it ice free.

https://link.springer.com/article/10.1007/s00382-017-3849-9

Reduce the FDD days enough, add enough heat in the atmosphere and the ocean and add convection to the top 1000m of the Arctic? Perhaps that would be enough heat to keep it ice free during the long cold Arctic night. 

How long will that take?.  Also consider shallow shelves on Laptev  Convection and warm currents might maintain ice free at north pole right through winter, but Laptev being shallow and protected from warm currents, and adjacent to cold land mass will take longer.  Consider current situation in Antarctica and north Pacific.  What is AML?  Something to do with stratification of Arctic?  Antarctica and North Pacific don't have this and manage to get ice in winter.  Just needs to be cold enough, so it depends on how long it stays cold enough.  Judging by model projections I'd say best guess is it will stay cold enough for centuries.

42
How many centuries does paleontology tell us it took to go ice free last time the earth was this warm and warming at this rate?

How warm was it last time paleontology told us it was ice free in winter?  I could look it up myself, but maybe those who want to appeal to paleontology should do the work?  Also +x degrees at equilibrium will be different from +x degrees while rapidly warming.  During rapid warming the land warms significantly faster than the ocean surface, and the ocean surface warms faster than the subsurface.  Both will make a big difference as to whether the ocean can resist several months of winter darkness/cold without freezing.  Arctic ocean surface might be an exception, but moreso in summer.  Outside Arctic is still going to warm slower than land and make a difference to how much heat is brought in by currents.

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Even volume? Even volume? You are aware the world does occur in 3D, right? How could you prefer extent more than volume?

I think I explained it just fine in my last post.  Is there some part of it you didn't understand.

There is a place for it, but the top indicator has to be volume...cuz it is, like,  the actual amount. Takes a certain amount of energy to melt a certain volume of ice.

Winter maximum isn't about melting ice, it is about conditions being cold enough for sea water to freeeze.

Speaking of madness...saying "well this is what is going to happen cuz a  few models say so..." is effectively like pontificating about what would happen in a zombie outbreak cuz thats what happened in Fortnite or Call of Duty waves. How good do you believe the models are? Can any models tell me what the weather will be like in a month?

Climate deniers don't like what the models say so run exactly the same argument.  Seems you don't like what the models are saying and so are running exactly the same argument.  This is a science based forum and not Watts Up with That.  The models are certainly imperfect, but whats a better method for predicting the future? 

44

How does the model maintain the cold halocline layer despite the lack of sea ice cover?

You're talking about a model of arctic sea ice decline, not a model of a blue ocean event.  We have no clue what that looks like, but the hypotheses floating around suggest papers in the next couple of years that begin to test the subject.  Models of arctic sea ice disappearance may be able to be sourced in such discussions right about the time it's happening right in front of our eyes.

I'm sure the model programmed by Arctic experts does a better job of predicting the influence of the cold halocline on sea ice than the guesses of members of this forum.

45
Ice free in winter is not going to happen in the next few centuries.


Ice free in winter already began happening in 1900.

My statement is probably going to end up being closer to reality than Michael's.

Based on what evidence?  Even the models that overestimate current ice loss do not get below 10m sq km of ice in winter by the end of this century.  I'd trust models over extrapolating a trend.  And extrapolating extent over extrapolating volume.  It is not how thick the ice is that determines ice free winter - it is the extent of ocean that is cold enough in the coldest part of winter to support the formation of ice.  Even extrapolating volume gives us another century until ice free winter.

46
Ice free in winter is not going to happen in the next few centuries.


47
Arctic sea ice / Re: The 2018 melting season
« on: August 04, 2018, 12:47:30 AM »
Quote
Even after a summer BOE, ice will still form in the Arctic during the dark, polar winter for many decades
So, this being merely 2018, it surely follows that Svalbard-FJL-SZ corridor froze over this winter?

Except it never came close. And this year was only a continuation of a long-term regional trend, not a variational swing attributable to unusual weather, cycle, oscillation, phase or teleconnection event.


Big difference between this region with deep water, and directly in the path of one of the warm currents from the Atlantic.  Compare to say Laptev with shallow shelfs and no direct exposure to warm Atlantic waters.  I note also that in this corridor the edge of the ice is pretty much in the same spot as it was at maximum.  Not exactly representative of general Arctic sea ice behaviour.

48
Arctic sea ice / Re: 2018 sea ice area and extent data
« on: August 02, 2018, 01:33:09 AM »
Massive drop in NSIDC SIE (253K, following 211K yesterday), second lowest on record now, causing massive uptick in compactness. Glitch or real?

I don't think the conditions in the Arctic were suddenly so much worse than the previous few days so at to more than double the rate of melt. 

If sensor variations can cause ice to be measured at 50k more or less on the day, then the sensors are working well, and measuring ice to about 1% accuracy (when area/extent is near 5m).  But then if daily losses are near 100k, and sensors switch from an overestimate of 50k to an underestimate of 50k, then sensors are reporting twice as much ice lost for the day as actually occurred.

49
Arctic sea ice / Re: When will the Arctic Go Ice Free?
« on: August 02, 2018, 01:02:39 AM »

If we are currently experiencing the effects of warming from CO2 emissions up to 2008 (to slightly simply things), then 380 ppm should correspond to about 1C temperature rise. SO SO SO SO SO WRONG. Last time concentrations were that high was a few million years ago and the temperature was significantly higher, sea level was significantly higher, and there wasn't any significant ice in the northern hemisphere. More recently, the co2 to temperature correlation would suggest at least 5C of warming from a 280 to 380 increase.

The graph you supplied is for temperature at Vostok (Antarctica) not global temps.  Also note that the primary temperature driver over this period was orbital changes - and then the temp changes drove CO2, and Co2 provided an additional feedback to warming.  So 5C in Antarctica is reduced by about half to get a global value, and then further reduced by however much of the warming was caused by orbital changes.

50
Arctic sea ice / Re: The 2018 melting season
« on: August 01, 2018, 12:36:01 AM »
Towards Siberia  looking far more solid than same date 2012

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