Poll: Where will the last Arctic Sea Ice be located?

[Tor Bejnar]

Where will the center of the last Arctic Sea Ice (ASI) be located, at the time of 1st 'ice-free' Arctic?

First, some definitions/rules:

* Ice-free Arctic means less than 1,000,000 sq. km. ASI extent as determined by any mainstream organization followed on the "Sea ice area and extent data" thread(s) that year (e.g., JAXA or NSIDC if it happened this year [but it won't happen this year]).

* The "winning" location(s) will be determined by community discernment.  See the map below for most area boundaries.  There may be co-winners. (1M sq.km. would just about fit in any of the 4 areas mapped below, but in real life will cross boundaries.)

* Maximum votes per user:  two (2).  If there were two major disconnected areas of ice, one might be north of Alaska and the other in the Greenland Sea, or maybe the last ice is a lozenge shape whose center is clearly off the coast of a pair of neighboring areas (e.g., Prince Patrick and Ellesmere Island regions).  There might be an hourglass look with the two lobes over non-neighboring areas.  If there are multiple lobes, each with their own center, the biggest two count.  If the center is north of Greenland and covers the North Pole, etc., etc.  If there is lots of ice in the CAA at the time, then it counts.

* You may not change your vote.

* You don't get to see how others voted until you vote.  Some people may discuss how they voted, of course, and you can see elsewhere where the ice is when there is 3 or 4 million sq. km. of ice left (or see my next post).

* Poll will be open for about 10 months.  You can vote now or wait until June 2021.  I don't expect the Arctic to go ice free before then!  (In fact, I hope option #7 wins, but I don't think it will.)

[Tor Bejnar]

A much better map than what I created June 15, 2015 (above)!

Mind you, by an ironic conincidence, "less than 1 million km2 of ice extent"  is almost exactly 15% of the average 1990s summer minimum...

Ha, I was wondering about that. Thanks, Peter. [...]

I like to say 'ice-free for all practical purposes', after hearing Walt Meier putting it like that once.

Someone has almost certainly already done this, but I don't know where, so I re-invented this wheel...

Here's a map showing what 1.0 million, 0.5 million, and 0.1 million km2 of ice extent could look like.  It's based on the grid cells with the maximum concentration in NSIDC September maps for the years 2008-2016.  My assumption is that ice will last longest in grid cells where Sept concentration is consistently the highest over the past decade.

[edit:  see map below]

If someone knows of a better version of this analysis here or elsewhere, please let me know!

Looking at the map, I'd say that 1 million km2 is actually a bit high for an "ice-free" threshold, personally.   

Recent maps of the Arctic ice, however, may suggest Ned's 2017 assumption won't pan out.

[Sebastian Jones]

Judging from this summer's ice movement, the last of the arctic ice will be in the Beaufort.

[Paddy]

I'm no expert, but I think that north of Greenland seems likely.  Often some thicker ice gets stuck there, and there's more glaciers shedding icebergs into that area than the rest of the arctic ocean put together.

[oren]

Judging from this summer's ice movement, the last of the arctic ice will be the patch south of Severnaya Zemlya...

[Tor Bejnar]

LOL, Oren!
Maybe the last of the ASI will be in cores stored at the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research in Bremerhaven, Germany!  (Wait, for most of the ASI be to stored as cores, the first less than 10⁶ km² extent year would have to also be a BOE .)

[igs]

West of Banks Island.

What counts IMO is not where the ice mostly is now, but where it mostly is drifting to and that is from north-west of CAA down to beaufort and once it will be the only small rest of remaining ice it will be driven down that path by currents and winds like it is now, just a bit quicker while the area north of it will be ice free for the same reason.

CAA may hold some ice but then we shall have to zoom in to max and use a magnifying glass.

[Bruce Steele]

That part of the pole hole 85 north that is under-lane by the Makarov Basin and the Fletcher Plain.

[binntho]

Interesting poll, but I am unable to vote since I am not seeing any option that fits what I think will happen once the ice goes under 1m km2.

In my view, once we get below a certain threshold, the rest of the ice will be dispersed and blown all over the place.  I don't expcect there to be any "center" to the remaining ice, but if it so happened that all the ice was continuous then it would also be moving very rapidly, and it's location totally dependent on the general wind direction of that melt season.

[Tony Mcleod]

...it would also be moving very rapidly, and it's location totally dependent on the general wind direction of that melt season.

True for all options except one: 'within the Canadian Arctic Archipeligo', which is why I chose it.

[crandles]

...it would also be moving very rapidly, and it's location totally dependent on the general wind direction of that melt season.

True for all options except one: 'within the Canadian Arctic Archipeligo', which is why I chose it.

If it was last 0.1m km2 then this would make sense to me. But I find it hard to imagine as much as .5m within archipeligo so with last 1m most is going to be outside.

I voted for after 2035, the scientists seem to have agreed on slowing rate of loss. When was the last time it wasn't boringly on/near the low edge of past years? 2012 maybe?

[Paul]

It's a funny one because I think it depends on the weather where the last bits of ice will be.

If you get a summer of the classic dipole, one would imagine the north coast of Greenland as ice will keep on being pushed into that area.

However if you get a summer where you don't get a true dipole but lots of reverse winds through fram, then the north coast of Greenland could become ice free as the fohen affect melts the ice and the remaining ice could be more nearer the CAA.

The currents would suggest it should be the north of Greenland as that image above shows but as we seen this summer, the ice is getting thinner and thinner.

Of course theres a possibility we may get a BOE but still have ice at the pole. I think Paul Beckwith kinda had a theory on that.

[binntho]

...it would also be moving very rapidly, and it's location totally dependent on the general wind direction of that melt season.

True for all options except one: 'within the Canadian Arctic Archipeligo', which is why I chose it.

If it was last 0.1m km2 then this would make sense to me. But I find it hard to imagine as much as .5m within archipeligo so with last 1m most is going to be outside.

I voted for after 2035, the scientists seem to have agreed on slowing rate of loss. When was the last time it wasn't boringly on/near the low edge of past years? 2012 maybe?

I don't see what the "archipeligo" has to do with my posting, but then again there are many things in this world that I don't understand.

But I'm pretty sure we'll see BOE before 2035 and I am wondering what scientists you are thinking of that have "agreed" on anything, let alone on slowing rate loss.

[Dallana]

But I'm pretty sure we'll see BOE before 2035 and I am wondering what scientists you are thinking of that have "agreed" on anything, let alone on slowing rate loss.

While the ice-loss could decrease in absolute numbers (only could) it will accelerate in relative numbers / percentage IMO.

After all the less ice and the less thick ice there will be, the warmer the sorounding waters will become, the warmer the air inflow will become and the more of the sunlight will penetrate the remaining thin and fragmented ice.

[oren]

Welcome, Dallana.

[Shared Humanity]

In some research lab's freezer. 

[crandles]

...it would also be moving very rapidly, and it's location totally dependent on the general wind direction of that melt season.

True for all options except one: 'within the Canadian Arctic Archipeligo', which is why I chose it.

If it was last 0.1m km2 then this would make sense to me. But I find it hard to imagine as much as .5m within archipeligo so with last 1m most is going to be outside.

I voted for after 2035, the scientists seem to have agreed on slowing rate of loss. When was the last time it wasn't boringly on/near the low edge of past years? 2012 maybe?

I don't see what the "archipeligo" has to do with my posting, but then again there are many things in this world that I don't understand.

But I'm pretty sure we'll see BOE before 2035 and I am wondering what scientists you are thinking of that have "agreed" on anything, let alone on slowing rate loss.

It was mainly a reply to Tony but I included quote from you for context.

Thought I remembered something recent as well as lots of older stuff but the recent item wasn't really what I said:

The surface albedo feedback is also state dependent
1287 such that reduced cryospheric extent will reduce its magnitude in a warmer climate (Jonko et
1288 al., 2012; Block and Mauritsen, 2013, Thackeray and Hall, 2019).

from https://bskiesresearch.files.wordpress.com/2020/07/wcrp_ecs_final_manuscript_2019rg000678r_final_200720.pdf

I admit I would struggle to show proof of agreement. My impression however is that more scientists are more inclined to tend towards William Connolley's stated view there will still be sea ice in summer 2050 than tending towards near term arctic sea ice disappearance views.

Graphs of many models like this generally show slow down in rate as zero is approached.


http://www.realclimate.org/images/seaice11.jpg

What I have understood of what scientists are saying is they tend to believe this emergent behaviour and to disbelieve straight line extrapolations al la Wadhams.

[Tor Bejnar]

a slightly updated map, Chris, is available on our very own "Graphs - Long Term Graphs".  Those projections, surely, were made many years ago.  What does AR5 say?

Here is a 'recent' paper suggesting faster ASI melt:
Fluctuations in Arctic sea-ice extent: comparing observations and climate models
Sahil Agarwal and John S. Wettlaufer
Published:20 August 2018 https://doi.org/10.1098/rsta.2017.0332

From the Introduction:

...
The global climate models (GCMs) from the IPCC Assessment Report 5 (AR5) project the Arctic to be ice-free by the middle of this century, whereas the previous assessment projected this to occur at the end of the century. The AR5 models project the Arctic to be ice-free as early as 2030 to as late as 2100 ([3], fig. 1 in [4]). ...

Perhaps this graphic should replace the "You are here 2012" graph on our Long Term Graphs page. Image is from
A sea ice free summer Arctic within 30 years: An update from CMIP5 models
Muyin Wang
James E. Overland
First published: 25 September 2012
https://doi.org/10.1029/2012GL052868

[Tor Bejnar]

Or this:
The urgency of Arctic change
James Overlanda, et al.
Polar Science
Volume 21, September 2019, Pages 6-13
https://doi.org/10.1016/j.polar.2018.11.008

Caption to Figure 4:

Fig. 4. September sea ice extent based on 82 ensemble members from 36 CMIP5 models under the RCP 4.5 scenario. Each thin colored line represents one member from a model. Up to five members per model are shown. The thick yellow line is the simple arithmetic mean of all ensemble members, and the blue line illustrates the median value. The thick black line represents observations based on the adjusted HadISST ice/sea ice analysis (https://www.metoffice.gov.uk/hadobs/hadisst/data/download.html). The horizontal black dashed line marks the 1.0 M km2 value, which indicates a nearly sea ice-free summer Arctic (Wang and Overland, 2009). The median suggests a sea-ice-free Arctic Ocean in late summer near the end of the century under RCP 4.5. However, observations and some models suggest that the Arctic Ocean could be seasonally ice-free significantly sooner (10–30 years; Overland and Wang, 2013). (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

[gandul]

I voted nowhere before 2035, I used to think around 2030 was a reasonable projection but I am increasingly convinced the current warming rate is not enough to get rid of the CAB ice before 2050. The conclusion of this very warm season suggests so.

Just as several scientific projections indicate.

[interstitial]

I voted nowhere before 2035, I used to think around 2030 was a reasonable projection but I am increasingly convinced the current warming rate is not enough to get rid of the CAB ice before 2050. The conclusion of this very warm season suggests so.

Just as several scientific projections indicate.

IMO this comes from focusing too much on extent numbers which do not show how degraded the central pack is. When the central pack was solid ice and a small ribbon on the periphery was degraded extent numbers were more indicative. A bit more heat in 2012 at the end of the melt season would not have changed extent much. Why? because the central pack was thick concentrated ice. Now the same amount of heat would have a much greater impact on remaining ice.

[Paul]

I voted nowhere before 2035, I used to think around 2030 was a reasonable projection but I am increasingly convinced the current warming rate is not enough to get rid of the CAB ice before 2050. The conclusion of this very warm season suggests so.

Just as several scientific projections indicate.

IMO this comes from focusing too much on extent numbers which do not show how degraded the central pack is. When the central pack was solid ice and a small ribbon on the periphery was degraded extent numbers were more indicative. A bit more heat in 2012 at the end of the melt season would not have changed extent much. Why? because the central pack was thick concentrated ice. Now the same amount of heat would have a much greater impact on remaining ice.

I really would not describe the CAB ice in 2012 as thick ice, it got quite diffused on the Laptev side in particular.

This year has quite concentrated ice but worryingly thin. Its just nowhere near as diffused as it was in 2016 especially.

And I do believe a diffused ice pack increases the chances of a BOE whilst a concentrated ice pack does not but one day, warm SSTS will win the day sadly.

[interstitial]

I voted nowhere before 2035, I used to think around 2030 was a reasonable projection but I am increasingly convinced the current warming rate is not enough to get rid of the CAB ice before 2050. The conclusion of this very warm season suggests so.

Just as several scientific projections indicate.

IMO this comes from focusing too much on extent numbers which do not show how degraded the central pack is. When the central pack was solid ice and a small ribbon on the periphery was degraded extent numbers were more indicative. A bit more heat in 2012 at the end of the melt season would not have changed extent much. Why? because the central pack was thick concentrated ice. Now the same amount of heat would have a much greater impact on remaining ice.

I really would not describe the CAB ice in 2012 as thick ice, it got quite diffused on the Laptev side in particular.

This year has quite concentrated ice but worryingly thin. Its just nowhere near as diffused as it was in 2016 especially.

And I do believe a diffused ice pack increases the chances of a BOE whilst a concentrated ice pack does not but one day, warm SSTS will win the day sadly.

To be fair thickness in 2012 and 2020 looks similar in some models but not the ones I trust. I think ice was consistently thicker at the end of 2012 melt season.
In comparison 2012 looked relatively more solid than 2020. Looking at thickness and concentration at the end of the 2012 melt season none of the ice looked like it was close to melting out. As it stands now in 2020 both thickness and concentration look ready to melt out over most of the central pack. I have no Idea why you think ice concentration is high this year it appears fragmented everywhere.

[oren]

This year is not so far from a BOE in my estimate, considering the North Pole images showing maybe 50cm of thickness, and the fast bottom melting of maybe 2-3cm per day still reported in the vicinity by a Mosaic buoy.
I wish Polarstern would release thickness data of typical CAB floes.

[kaixo]

This year is not so far from a BOE in my estimate, considering the North Pole images showing maybe 50cm of thickness, and the fast bottom melting of maybe 2-3cm per day still reported in the vicinity by a Mosaic buoy.
I wish Polarstern would release thickness data of typical CAB floes.

I agree with Oren here. And with Binntho as wel:

...it would also be moving very rapidly, and it's location totally dependent on the general wind direction of that melt season.

September ice is very thin in high melt years. As for a slow down in the trend line for yearly extent minima and thus a prolonged period with low mins but no BOE, i think the opposite is true.

If you look at the decadal averages in the arctic sea ice volume death spiral graph, you can clearly see that the 'dent' in september/october is getting more strongly pronounced every decade.

http://iwantsomeproof.com/extimg/sie_nsidc_annual_polar_graph.png



To me this suggests a shift in dynamics at the end of the melt season and a BOE (translated in volume as < 1.000 km3 more or less) that is not far away, probably even this decade.

Where the last ice will be, will be very weather dependent. It could as well be in the Barents as in the Beaufort, to make a nice alliteration, blown away from the pole.   

Edit: Sorry for posting the graph twice, don't know how to delete the second one without the first as well.

[oren]

Edit: Sorry for posting the graph twice, don't know how to delete the second one without the first as well.

Fixed it for you kaixo. One was a web image using the {img} tags, the other was an attachment which I removed.

[kaixo]

Fixed it for you kaixo. One was a web image using the {img} tags, the other was an attachment which I removed.

Thanks Oren. I have been reading the ASIF main threads nearly daily for many years now, but i hardly ever post anything so i'm not very handy in adding images and so on.
Just like Neven all those years before, you are doing a great job and it's amazing you take time to fix even little irritating things like my double graph.   

[kassy]

I voted north of Greenland/Ellesmere island but it is that general area. It could also be more towards Canada or Beaufort near there.

Essentially that means that the Central Arctic fails first and this is because it will be surrounded by ever more open water for longer during the year. The Beaufort Gyre is not putting thick ice back in so at some point it will fracture early because the old ice back bone is not there and then it will all float somewhere and melt from the sides etc.

The remnants will be near the cooler parts so Greenland Canada side.

[Tor Bejnar]

If interested in polls on these threads, check out
When will 2020 JAXA extent cross 2012?

[Positive retroaction]

 I choosed 2 options:
North Greenland/ellesmere or CAA
I think that Greenland with its low T will be the last capable of promoting the formation of sea ice on its northern edge, if they are weak, the presence of GAAC could push them back to the north of the CAA
They would then be difficult to dislodge by the wind in these channels of the north CAA, for me the north CAA would be the last support for the drifting ice
Sory my English is bad, but my fascination for ASI is big

[Tor Bejnar]

By the way, this poll is open for about 7 more weeks.  (And some of you probably hoped I had forgotten!)

[Glen Koehler]

     The final tiny bits of ASI will be in the nooks and crannies of the CAA.  As functional components for planetary climate control the area they cover will be insignificant, but that is where I expect the ice to reside longest. 
     Edit - oh, I see, I have to push a button to vote.  Got it.  No wonder the US has such election problems with people like me in the electorate.  If my selection doesn't win, can I demand a recount?  Of course, if that happens, it must have been rigged from the start... many people are saying.  We love, you are special people.  (inside joke, for those of you not obsessed/distressed with recent US events).

[Ktb]

Thanks for bringing this back, I had missed it originally.

[kassy]

Also note it asks about the center of the remnants.
Staying with my original vote.

[pearscot]

I voted Greenland/Ellesmere, and I also think there will be variable and sometimes winters where the sea ice on the Siberian side take a while to melt.

[Iain]

In a refrigerated museum exhibit?

"Look kids - real sea ice"

Seriously - North of GL or if swept away to the Atlantic, small remnants stuck in the CAA

[Tor Bejnar]

Extra, extra, read all about it...
In this case, I want to read what you think or guess or dream or contrive or joke will be the remaining location or locations of Arctic Sea Ice the year it declines down to 1 million km squared extent.

How about 1/3 around the NP, just less than 1/3 in the Greenland Sea, s smidgen in undesignated North Atlantic and 1/3 in the Barentsz Sea. [Link is to the regions map available in ASI Graphs.]

[I’M IN LOVE WITH A RAGER]

I am also very curious about what the eventual answer to this question will be. It may be very surprising looking back on this thread in 5-10 years, considering the latest developments north of Greenland. I’ve always thought the triangular ice mass from north of the CAA and Greenland to the pole would be the final holdout, but I now wonder if the actual result may be more up to weather and luck than historical trends or anything else.

We may be closing in on a future where all of the ASI is vulnerable as long as the right weather patterns materialize. Previous consistent holdouts may no longer be the strongholds they were once seen as. My hypothesis is that the last few years leading up to the first ice free summer will have quite odd pack shapes that might prove to be surprising to many of us on the forum, even with our existing body of knowledge. Uncharted waters and strange times may lie ahead

[kassy]

The final image shows the average open water in mid-September over the last ten years. The Last Ice Area can only be a subset of the white core ice area -- already the ice shelves, landfast ice along the CAA coast and peripheral seas can be ruled out as part of any ice refugium.

A good post for musing about the fate of your prediction. Not so good for mine although widening the definition of north might help (i assume north of Greenland is a shorthand for attached to the coast there).

Also see my post 2 below the one linked above.
I think the Wandal Sea Polynya will be with us from now on. It would take a really strange wind pattern to push it to the coast and of course there is no incoming thick ice as we had in the good old days.