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Frivolousz21

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Re: The 2020 melting season
« Reply #3650 on: July 25, 2020, 08:00:47 AM »
Concentration on the Pacific side continues to plummet.

Here is my current prediction for the sea ice min.

I'd love to see everyone's thoughts.

I tried the same the other they by erasing the thinnest ice from HYCOM. My results are not dissimilar from yours. As others said it is cca 2,5 mln sq km. I think yours is smaller though I am not sure:

That green area looks very realistic.

The hardest part is that their will likely be a lot of open water within the main pack.

The MATH proves that a large portion of the basin is likely to melt out by the end.

Winds have been so benign and non turbulent.  So a lot of thin weak ice has remained intact.

It will either melt out in place or vanish quickly under turbulence.


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oren

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Re: The 2020 melting season
« Reply #3651 on: July 25, 2020, 08:29:26 AM »
Sorry if this has been addressed but lacking super-high-res views what I think I've seen in some of the wondrous animations presented is "compaction" where hundreds of broken flows all shrink somewhat in size and shuffle northwards if by fairly gentle winds. This doesn't dispute that pressure can induce ridging but it simply looks like everything was shifted back to fill in the gaps from melting edges of hundreds of smaller and smaller ice-flows.

Mine is an untrained eye but that's what I think I see, and that impression was before I started reading debates about what sort of compaction was happening. $0.02 and that that's you've overpaid.
Welcome Icy voyeur2. That discussion has generally been moved to a separate thread "the science of rafting and ridging", if you wish to follow it.
Btw it's floes, not flows...

JamesW

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Re: The 2020 melting season
« Reply #3652 on: July 25, 2020, 09:49:59 AM »
Well 24 hours later and numerous changes in the forecast yesterday on GFS showing the Beaufort low weakening, the 3 day forecast now shows it is back and strengthening to a possible 976 with increased wind speeds over 50kmph. Now appearing more likely to have an impact as the forecast becomes more reliable within the 72 hour period.

pauldry600

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Re: The 2020 melting season
« Reply #3653 on: July 25, 2020, 09:54:42 AM »
I dont think it will be as low as 2.5million but the 2012 3.12million is very reachable but what do I know?

I said around 3.8 or 3.9million originally and just squint my eyes at the devastation that's going on up there.

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Lord M Vader

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Re: The 2020 melting season
« Reply #3654 on: July 25, 2020, 10:17:47 AM »
First, Resolutes all-time-high is 20.1° from July 2 by 2012.

Second, Friv, I think your map over the minimum is somewhat pessimistic. I don't think that the Laptev bite will make it all the way to the pole. It should be close though and only depend on that time is running out. A bite reaching to 88-89°N seems very realistic given that HYCOM is right. A minimum around 3MN km2 is right now a likely outcome.

Third, the latest forecast from EC is very problematic. The Beaufort should get seriously hammered by the sub 980-cyclone. And the extent losses will likely be slow or very slow for the rest of July.

Fourth, another thing of concern is how much ESS and Chukchi will warm up until fall and cooling will start. Kara, Laptev and Baffin are supercharged with heat and will take time to cool down.

And finally, fifth, a new record low extent is not the worst thing to happen. A new records low volume is. And especially if we are going to see the thickest ice take a huge damage the next 10 days. That should make next melting season primed for another record low. We can't hope for another winter with such a strong polar vortex.

Aluminium

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Re: The 2020 melting season
« Reply #3655 on: July 25, 2020, 10:47:27 AM »
This cyclone in the Beaufort doesn't seem too strong though is not weak. Still, there is a lot of ice and new lowest in September probably requires something more.

Yossarian80

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Re: The 2020 melting season
« Reply #3656 on: July 25, 2020, 10:58:50 AM »
Models should now have a decent handle on the initial evolution of our upcoming storm. The vortmax, jet streak and surface low actually exist and are well defined now in northern Siberia, so that always helps with modeling. Looks like the low will move into the arctic, deepen, and feed on the baroclinic zone between the northern Siberian heat, and the relatively cool arctic.

Pretty interesting evolution as it then may pinwheel around a bit, also feeding off the North American heat as well, consuming the potential energy along the Arctic Frontal Zone near both continents. The heat and anomalous ridging in ne Siberia and nw Canada should not be there. This is not normal, and a symptom of a chaotic system cascading into some kind of new normal. I fear storms like this will become more and more common until the summer sea ice is gone resulting in a weaker Arctic Frontal Zone.

But I ramble... as for this specific storm, the potential is there to do some damage. But unlike the GAC of 2012, this storm has less open sea to work with to create fetch for waves. The sea ice was roughly 500km north off the Alaskan coast before that storm, but now only 100km. Still, The exact positioning and motion of the storm will be important. If the storm is strong/persistent enough and positioned to create a fetch of wind from the Chukchi towards the Beaufort then some serious damage could be done to the ice.

Looking at satellite and concentration maps, the sea ice on the Pacific side is extremely vulnerable. This will be interesting to watch. 0z ECMWF 96hr forecast attached with SLP and 850mb wind (kts).

Paul

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Re: The 2020 melting season
« Reply #3657 on: July 25, 2020, 11:50:00 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 24th, 2020:
     6,042,112 km2, a small drop of -5,029 km2.

I've got a bad feeling about this. Spreading ice is dead ice.

It depends how much ice has spread also mind because the set up at the moment should favour low drops regardless what year it is really. That said, I do agree generally that very low drops like that may look good to help the extent line to catch up to the pack but longer term inn this melt season it may lead to more vulnability.

Regarding the Beaufort low potential, the models have ramped it up again.. I do sometimes think low pressure systems get hyped up a bit because of what happened in 2012* but it certainly worth watching because the Beaufort ice is showing more vulnability and whilst I don't think the storm will accelerate ice loss in the Beaufort short term, it could potentially disperse the ice even more.

* the ice loss of the GAC came from the fact the storm went right through a part of the ice pack that was severely vulnable and broke a large part of the ice away from the ice pack.

gandul

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Re: The 2020 melting season
« Reply #3658 on: July 25, 2020, 12:13:44 PM »
This cyclone in the Beaufort doesn't seem too strong though is not weak. Still, there is a lot of ice and new lowest in September probably requires something more.
That’s not correct imo. A low around 980 hPa or below with strong but concentrated winds, four days persisting over the worst location to accelerate floe breakup (while the rest of the Arctic keeps relatively warm) is a very bad scenario. A very stagnant weather must come for the rest of for August to “save” Beaufort ice.
Edit: I keep forgetting while looking at the Arctic that we have still one week before August!
« Last Edit: July 25, 2020, 12:20:09 PM by gandul »

FishOutofWater

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Re: The 2020 melting season
« Reply #3659 on: July 25, 2020, 12:28:18 PM »
Yossarian, the location of this low is very bad for the ice because it will pull continental heat over the pole while concentrating dispersion at the ice edge in the Chukchi and Beaufort seas. The ice dispersion will be in the location where it can inflict the most melting. That Beaufort and Chukchi ice has ocean heat under it and we're not talking about 300m down, either. We're talking about heat that's pretty close to the surface, in the top 100m of the ocean.

This moderately strong storm is positioned to do some damage.

Yossarian80

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Re: The 2020 melting season
« Reply #3660 on: July 25, 2020, 12:45:08 PM »
Yossarian, the location of this low is very bad for the ice because it will pull continental heat over the pole while concentrating dispersion at the ice edge in the Chukchi and Beaufort seas. The ice dispersion will be in the location where it can inflict the most melting. That Beaufort and Chukchi ice has ocean heat under it and we're not talking about 300m down, either. We're talking about heat that's pretty close to the surface, in the top 100m of the ocean.

This moderately strong storm is positioned to do some damage.

Yes I agree... if the recent runs are correct, then it will be in the absolute worst spot to do damage. And good point about the heat being pulled to the pole. The wind associated with the low and overall -DA should help all that 850mb heat mix down and be realized at the surface as well, in the form of lots of melting. Not good.

glennbuck

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Re: The 2020 melting season
« Reply #3661 on: July 25, 2020, 12:52:44 PM »
Arctic again in a warm cycle..2.1C over average

gerontocrat

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Re: The 2020 melting season
« Reply #3662 on: July 25, 2020, 01:09:00 PM »
There was a bit of a discussion yesterday about Albedo Warming Potential (AWP) . Here is some further speculation.

I attach graphs of accumulated AWP anomalies from NICO Sun 's website https://cryospherecomputing.tk/NRTawp.
It is high, close to the 2016 and 2019 values.

This is potential, not actual, energy being applied to and absorbed by the surface of the Arctic Seas. However, the GAAC during a period of high insolation giving more than usual clear skies surely means that actual energy applied to the ocean surface was higher than usual. .

The last graph has the cumulative AWP potential of each sea. The Kara Sea AWP is through the roof. With clearer skies than usual, surely it is no wonder SST's are so high in that sea.

Perhaps there is momentum for further melting simply because of high energy absorption in the last month or so.

Wouldn't it be marvellous if the data on clouds and its effect on insolation reaching the surface was good enough to produce Albedo Warming Actuality.
______________________
ps: Nico Sun has documented everything he has produced at https://cryospherecomputing.tk/doc.html

Here is his explanation of the AWP calculation

The Albedo-Warming Potential (AWP) quantifies the additional ocean warming from a lower ice cover at the poles. These calculations don't include cloud cover, therefore it is called "Warming Potential" and not actual warming. However, over the six-month period weather tends to average out and warm areas correlate well with low ice extent in September. The basis of all calculations is a global surface radiation model and NSIDC Sea Ice Concentration data.

Formula per gridcell
AWP Daily = ((1-SIC) * MJ) + 0.15 * MJ * SIC
AWP Accumulated = sum(AWPdaily)
MJ = incoming surface radiation per square meter
SIC = Sea Ice Concentration

The calculated values are arithmetic averages over the whole maximum possible ice extent (shown in light blue). All lakes and some marginal seas (Baltic Sea, Gulf of St. Lawrence) are not considered because their coastline to total area ratio is too high. Coastline measurement errors introduce just random noise.


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FishOutofWater

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Re: The 2020 melting season
« Reply #3663 on: July 25, 2020, 01:49:13 PM »
GC - Thanks for that explanation of Nico Sun's AWP. It is not a potential field as in physics.

The big problem with the concept is that the high Arctic has a 6 week period of intense insolation so the assumption that weather tends to average out may be false. It surely is false this year. I won't repost the maps of outgoing longwave radiation but they prove that more shortwave radiation has been reaching the surface and more longwave radiation has been emitted back to space. I think that Nico has done excellent work, but we need to recognize its limitations.

grixm

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Re: The 2020 melting season
« Reply #3664 on: July 25, 2020, 01:50:47 PM »
How is this ice here being so robust? It's very warm in the water and air, there's little other ice around to buffer the heat, and last PIOMAS update the 15th said that the ice was quite thin at that time. Yet it is still there in significant amounts, it almost doesn't look like it has melted much at all in the past week or two.

NotaDenier

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Re: The 2020 melting season
« Reply #3665 on: July 25, 2020, 02:13:22 PM »
How is this ice here being so robust? It's very warm in the water and air, there's little other ice around to buffer the heat, and last PIOMAS update the 15th said that the ice was quite thin at that time. Yet it is still there in significant amounts, it almost doesn't look like it has melted much at all in the past week or two.

I believe if you look at the thickness models, that was some of the thickest ice. I can’t see it surviving August with how isolated it is and southerly it is. This season will be destructive to some of the thickest ice in the arctic.

We will probably see something similar in the Beaufort when it finally melts out. I don’t believe the thickest ice in the Beaufort will melt out however. For reference remember the big block from 2016?

I find it interesting that the shape of the ice pack is starting to resemble the final shape from 2012. I wonder if this is due to the bathymetry of the CAS? 

Pagophilus

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Re: The 2020 melting season
« Reply #3666 on: July 25, 2020, 02:14:28 PM »
July 20-24.

Thanks again for the animation, Aluminium.

What I think I see in the animation is the end of the general clockwise motion of the icepack, which drives convergence of floes, and the beginnings of a general anticlockwise motion, which drives divergence of floes.  All weather driven, of course.  The Atlantic front, in particular, has ballooned out a little over the past five days, sending floes towards oblivion there.  Anticlockwise motion will also tend to close the large coastal cracks N of Greenland and Canada IMO.

I am in complete agreement with some others... declining extent losses, or even more troublingly, extent gains, are and will be a really negative sign for the ice, since that ice has nowhere to go but into the warmer surrounding waters if it is dispersed.     
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uniquorn

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Re: The 2020 melting season
« Reply #3667 on: July 25, 2020, 02:34:22 PM »
whoi itp buoys, Beaufort, ocean temperature (and other data) at 6m depth.
click

Pagophilus

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Re: The 2020 melting season
« Reply #3668 on: July 25, 2020, 02:48:07 PM »
How is this ice here being so robust? It's very warm in the water and air, there's little other ice around to buffer the heat, and last PIOMAS update the 15th said that the ice was quite thin at that time. Yet it is still there in significant amounts, it almost doesn't look like it has melted much at all in the past week or two.

I believe if you look at the thickness models, that was some of the thickest ice. I can’t see it surviving August with how isolated it is and southerly it is. This season will be destructive to some of the thickest ice in the arctic.

We will probably see something similar in the Beaufort when it finally melts out. I don’t believe the thickest ice in the Beaufort will melt out however. For reference remember the big block from 2016?

I find it interesting that the shape of the ice pack is starting to resemble the final shape from 2012. I wonder if this is due to the bathymetry of the CAS?

IMO you are either absolutely right or there is an amazing coincidence.  Here is bathymetry and ice concentration for July 24, a match that is part of a continuing trend, and one that is getting closer.

Any future dispersal takes takes ice out of the deep water zone, with its cold freshwater lens floating on top, and into the sunwarmed waters around.

https://oden.geo.su.se/map/   Largish gif.  Click to animate.
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Thomas Barlow

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Re: The 2020 melting season
« Reply #3669 on: July 25, 2020, 03:30:34 PM »
How is this ice here being so robust? It's very warm in the water and air, there's little other ice around to buffer the heat, and last PIOMAS update the 15th said that the ice was quite thin at that time. Yet it is still there in significant amounts, it almost doesn't look like it has melted much at all in the past week or two.

I believe if you look at the thickness models, that was some of the thickest ice. I can’t see it surviving August with how isolated it is and southerly it is. This season will be destructive to some of the thickest ice in the arctic.

We will probably see something similar in the Beaufort when it finally melts out. I don’t believe the thickest ice in the Beaufort will melt out however. For reference remember the big block from 2016?

I find it interesting that the shape of the ice pack is starting to resemble the final shape from 2012. I wonder if this is due to the bathymetry of the CAS?

IMO you are either absolutely right or there is an amazing coincidence.  Here is bathymetry and ice concentration for July 24, a match that is part of a continuing trend, and one that is getting closer.

Any future dispersal takes takes ice out of the deep water zone, with its cold freshwater lens floating on top, and into the sunwarmed waters around.

https://oden.geo.su.se/map/   Largish gif.  Click to animate.
It's a great point. I haven't seen that before. Even the CAA has some pretty deep channels, and the ice always stays thicker in those (but not in the Nares, which is shallower). Probably a no brainer for a lot of people, but I never saw that pointed out before.

Aluminium

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Re: The 2020 melting season
« Reply #3670 on: July 25, 2020, 04:18:40 PM »
A low around 980 hPa or below with strong but concentrated winds, four days persisting over the worst location to accelerate floe breakup (while the rest of the Arctic keeps relatively warm) is a very bad scenario. A very stagnant weather must come for the rest of for August to “save” Beaufort ice.
Maybe, in the most pessimistic scenario, but I would not pay too much attention to 970+ low here until specific circumstances. The Beaufort was quite resilient this summer and saved plenty of ice. There is not positive AWP anomaly. To significantly improve chance of new record in extent, damage should be very hard here. I think, the Beaufort Sea has a great chance to withstand. However, many other places have not. The Laptev Sea, for example, is already overheated and very dangerous for the nearest CAB.
« Last Edit: July 25, 2020, 04:30:05 PM by Aluminium »

BornFromTheVoid

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Re: The 2020 melting season
« Reply #3671 on: July 25, 2020, 04:19:01 PM »
With little change in the last 2 days, the NSIDC extent is now lowest on record by 481,000km2, and less than 1 million km2 below the 2010s average again.

The simple projection only produces a new September low for 6 of the last 20 years. The 10 year average melt will reach a low of 3.6 million km2, or 2nd lowest on record.
https://twitter.com/Icy_Samuel/status/1287026915765780480
https://twitter.com/Icy_Samuel/status/1287027525630275586
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

oren

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Re: The 2020 melting season
« Reply #3672 on: July 25, 2020, 05:04:03 PM »
I find it interesting that the shape of the ice pack is starting to resemble the final shape from 2012. I wonder if this is due to the bathymetry of the CAS?

IMO you are either absolutely right or there is an amazing coincidence.  Here is bathymetry and ice concentration for July 24, a match that is part of a continuing trend, and one that is getting closer.

Any future dispersal takes takes ice out of the deep water zone, with its cold freshwater lens floating on top, and into the sunwarmed waters around.
[/quote]
I believe this more of a coincidence than meets the eye. In normal years the deep Beaufort is much emptier of ice, the shallower ESS often has lots of ice at this stage. And this year the deep Laptev/CAB sector is ice-free.
The coincidence is created by the general ice transport regime in the Arctic - from Siberia towards Ellesmere.
The only region where the correlation is not coincidental is where the Barents meets the CAB. There the incoming Atlantic Water sinks below the fresher surface waters thanks to the deeper bathymetry, thus creating a typical demarcation between the ice-free and ice-covered regions.

oren

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Re: The 2020 melting season
« Reply #3673 on: July 25, 2020, 05:06:23 PM »
7(!) off-topic posts moved to the Vavilov Ice Cap thread.
ArcticMelt2, please bear in mind not all interesting things automatically go in this thread.

uniquorn

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Re: The 2020 melting season
« Reply #3674 on: July 25, 2020, 06:04:20 PM »
I believe this more of a coincidence than meets the eye. In normal years the deep Beaufort is much emptier of ice, the shallower ESS often has lots of ice at this stage. And this year the deep Laptev/CAB sector is ice-free.
amsr2-uhh overlaid onto gmrt bathymetry, minimum jaxa dates, 2012-2018
must add 2019 sometime.
edit:Perhaps someone will put together all the nsidc minimums one day. I think they go back a lot further. If they do, I will attempt to overlay them onto bathy.
« Last Edit: July 25, 2020, 06:36:59 PM by uniquorn »

RoxTheGeologist

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Re: The 2020 melting season
« Reply #3675 on: July 25, 2020, 06:17:40 PM »
I believe this more of a coincidence than meets the eye. In normal years the deep Beaufort is much emptier of ice, the shallower ESS often has lots of ice at this stage. And this year the deep Laptev/CAB sector is ice-free.
amsr2-uhh overlaid onto gmrt bathymetry, minimum jaxa dates, 2012-2018
must add 2019 sometime

Great post, as always.

oren

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Re: The 2020 melting season
« Reply #3676 on: July 25, 2020, 06:18:55 PM »
Animation of the Beaufort and some CAB in 3-day increments. M'Clure Strait is at the bottom.
The amount of open water between the floes is worrying, and definitely increasing. Admittedly there is a lot of ice in the Beaufort this year, but a lot of the gray rubble could easily and quickly disappear.
Click to animate.

Pagophilus

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Re: The 2020 melting season
« Reply #3677 on: July 25, 2020, 06:22:39 PM »
I believe this more of a coincidence than meets the eye. In normal years the deep Beaufort is much emptier of ice, the shallower ESS often has lots of ice at this stage. And this year the deep Laptev/CAB sector is ice-free.
amsr2-uhh overlaid onto gmrt bathymetry, minimum jaxa dates, 2012-2018
must add 2019 sometime

Great animation, uniquorn.  Thank you!   And I bow to your much greater experience, Oren, so I recognize the following is only speculation. 

I am reading the extent minima on the animation as sometimes not correlating so well with bathymetry (always above deep water but not so much bounded by the 200m submarine contour), but in other years lining up fairly closely with the frequent exceptions of the Beaufort and the Laptev. 

In other words, it seems to me that the 'bathymetric effect' goes beyond the continental Canadian-Greenland boundary and the Atlantic front.  2016, 2017 and 2018 seem to be examples of this.   But I guess the floating cold fresh water can only protect the ice to some extent in a long, punishing melting season, and the boundaries go well inside the 200m submarine contours at season's end. 
« Last Edit: July 25, 2020, 06:39:08 PM by Pagophilus »
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RunningChristo

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Re: The 2020 melting season
« Reply #3678 on: July 25, 2020, 06:32:43 PM »
21.7C at Longyearbyen, Svalbard today, thus "shattering" the previous max dating back to July 1979! Another poor year for the retreating glaciers up there...
My fancy for ice & glaciers started in 1995:-).

bbr2315

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Re: The 2020 melting season
« Reply #3679 on: July 25, 2020, 06:38:12 PM »
Uh oh....

12z GFS stronger than 00z // now 971 min vs 974...

Maybe we see 960s?

In either case Beaufort / Chukchi are about to collapse and the fetch between the GAAC and GAC will do major damage to the entire CAB as well. I think we are about to see a lot of the pack collapse to 2016-esque appearance but the difference is that most of the mush this year could very well melt.


BornFromTheVoid

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Re: The 2020 melting season
« Reply #3680 on: July 25, 2020, 06:46:34 PM »
While extent has flat-lined over the last 2 days, the concentration continues to drop, especially in the Beaufort sea. It will be interesting to see how it deals with the low pressure early next week.
https://twitter.com/Icy_Samuel/status/1287065182452187136
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

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Re: The 2020 melting season
« Reply #3681 on: July 25, 2020, 06:51:14 PM »
CMC agrees w GFS has low down to 966mb...


gandul

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Re: The 2020 melting season
« Reply #3682 on: July 25, 2020, 06:58:14 PM »
I believe this more of a coincidence than meets the eye. In normal years the deep Beaufort is much emptier of ice, the shallower ESS often has lots of ice at this stage. And this year the deep Laptev/CAB sector is ice-free.
amsr2-uhh overlaid onto gmrt bathymetry, minimum jaxa dates, 2012-2018
must add 2019 sometime.
edit:Perhaps someone will put together all the nsidc minimums one day. I think they go back a lot further. If they do, I will attempt to overlay them onto bathy.

That sequence shows the effect that storms after storms had on 2016 (including a 3 in 1 GAC and a legendary garlic press). The year that bbr predicted the cleavage and was mocked for it eternally thereafter by the pundits around, only that it in fact happened.

Oren’s gif shows the effect of weak but continuous cyclonic conditions over Beaufort combined with the overall drift at Arctic scale. Now going to grt a much stronger shock, where average floe size will start to cascade down toward the meters scale, with top, bottom, lateral melting, wave wash over, floes tilting, ekman transport etc. etc. multiplying ocean => ice heat transport.

While probably the thinned ice in Central CAB will float under a gentle breeze melting but not really melting out (this week, at least)
« Last Edit: July 25, 2020, 07:04:46 PM by gandul »

glennbuck

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Re: The 2020 melting season
« Reply #3683 on: July 25, 2020, 07:05:14 PM »
We're 5 days ahead of 2019, 7 days ahead of '12, between 9-14 days ahead of '11-'18.
The thicker dashed blue line is the average of 2001-'05, we're >A Month ahead.


FishOutofWater

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Re: The 2020 melting season
« Reply #3684 on: July 25, 2020, 08:19:28 PM »
Now the ECMWF has a convincing forecast that agrees well with the GFS of a deep low that is in pretty much the worst possible location for the ice. The ice will be mixed into the ridiculously warm waters on the Siberian side. Now it's looking like this is going to be an historic year for sea ice.

Insane warm air advection from the CAA and hot compressing air downsloping off of Greenland towards the pole and across to Siberia. With strong winds to mix the heat down to the ice.

click to play (courtesy of Tropical Tidbits)
« Last Edit: July 25, 2020, 08:56:25 PM by FishOutofWater »

BornFromTheVoid

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Re: The 2020 melting season
« Reply #3685 on: July 25, 2020, 08:48:26 PM »
I put together a little animation using the GFS ensembles probability of 50km/h winds and the latest concentration map. (click to play)
I recently joined the twitter thing, where I post more analysis, pics and animations: @Icy_Samuel

FishOutofWater

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Re: The 2020 melting season
« Reply #3686 on: July 25, 2020, 08:53:58 PM »
We have an absolutely insane week of weather ahead. Please observe the deep low in the Chukchi & Beaufort seas, the hurricane developing in the main development region of the Atlantic and the crazy storm that tracks from the coast of Spain to the east coast of central Greenland advecting north African air towards the pole. There's strong agreement of the ECMWF and GFS on all three storms, giving us confidence in the forecast. The ECMWF takes the hurricane into the Caribbean while the GFS takes it north of the Caribbean but there's really strong agreement on the 2 storms that will advect enormous amounts of heat from the north American and Atlantic sides towards the pole.

I should be posting this in all caps for drama, but it's not my style.

bbr2315

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Re: The 2020 melting season
« Reply #3687 on: July 25, 2020, 09:01:09 PM »
If the 12z EURO forecast verifies I think we are nearing 100% probability of a minimum under 2.5M KM^2 for extent, and I also think the possibility of under 2M KM^2 is also now becoming apparent, although it is not likely.



I don't think you could create a worse forecast for the Arctic for the time of year if you tried although perhaps that is what the 12z CMC attempted to do.  :P

It should also be noted that the trend over the past 24 hours has been to severely deepen this low. There is also a possibility the models are going to continue this, which means a minimum pressure of under 970 is now quite possible, and 960 is not unfeasible.

The below GIF is actually not an unreasonable representation of what is going to occur to the sea ice over the next ten days or so as the Beaufort Chukchi collapse, potentially cleaving the pack into the remnant CAB and MYI floes on its periphery. While the CAB will remain floating for a bit while longer..... make no mistake, the water is rushing in.


Yossarian80

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Re: The 2020 melting season
« Reply #3688 on: July 25, 2020, 09:17:16 PM »
Awesome view of our future arctic storm on Worldview today... the storm (center right on image) will rotate around the Siberian ridge and enter the arctic, while rapidly deepening. The smoke underneath the ridge from the tremendous amount of wildfires is also plainly visible (top center/left on image). It really is a crazy world we now live in.

https://worldview.earthdata.nasa.gov/?v=-1912579.7545871844,1313271.024213506,2077227.9687748204,3561050.023290692&p=arctic&l=Reference_Labels(hidden),Reference_Features(hidden),Coastlines,VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor

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Re: The 2020 melting season
« Reply #3689 on: July 25, 2020, 09:37:38 PM »
What is the likelihood that the entire ice sheet will unfasten from the CAA and Greenland?  In the years I've been watching I don't remember seeing anything quite like this.  I did not go through every frame of every year, but it looks like it could just lift away in the not distant future.  The ice is very broken up in much of the Canadian, CAA, edge of the CAB, and it has lifted away from North Greenland. No fast ice?  The picture is today north coast of Greenland and nearby CAA.
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prokaryotes

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Re: The 2020 melting season
« Reply #3690 on: July 25, 2020, 10:16:53 PM »
Laptev and ESAS large parts now essentially ice free...
Quote
The disappearing #Arctic sea ice along the Siberian coastline...

[Daily data from 3-km AMSR2 satellite since June 1]
https://twitter.com/ZLabe/status/1286660849885536261


uniquorn

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Re: The 2020 melting season
« Reply #3691 on: July 25, 2020, 10:21:09 PM »
What is the likelihood that the entire ice sheet will unfasten from the CAA and Greenland?
Quite likely for a few days.

Drift update from a few more iabp buoys, including one in the ESS and a few more mosaic buoys on the atlantic side. Also one that's apparently being deployed in the west spitsbergen current.
click 10MB

The second animation is shorter with 10s delay in case anyone needs the numbers.
The titles are incorrect. These are not all whoi buoys, just iabp
edit: lol bbr. How will it hit an iceberg if they all melted?   ;)
« Last Edit: July 25, 2020, 11:22:42 PM by uniquorn »

RoxTheGeologist

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Re: The 2020 melting season
« Reply #3692 on: July 25, 2020, 10:54:59 PM »
What is the likelihood that the entire ice sheet will unfasten from the CAA and Greenland?  In the years I've been watching I don't remember seeing anything quite like this.  I did not go through every frame of every year, but it looks like it could just lift away in the not distant future.  The ice is very broken up in much of the Canadian, CAA, edge of the CAB, and it has lifted away from North Greenland. No fast ice?  The picture is today north coast of Greenland and nearby CAA.

With high winds perpendicular to the coast we can add upwelling of deeper and warmer water to the brew,

HapHazard

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Re: The 2020 melting season
« Reply #3693 on: July 25, 2020, 11:22:02 PM »
I'm seeing knowledgeable posters like bbr & foow & friv & void etc. agreeing on what looks to be coming right around the corner... Making me too nervous. Time to put on my backpack & hike up above the treeline here for a few hours...  :-\
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Frivolousz21

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Re: The 2020 melting season
« Reply #3694 on: July 25, 2020, 11:36:40 PM »
In RESOLUTE, CA It's currently 18C with a 8.3C dewpoint and a SE wind of 22km/hr.



In EUREKA, CA it's 21.3C or 70.5F with a DP of 3C and winds WSW at 12km/hr.

At Grise Ford a coastal CAA city just south of EUREKA. ... It's 13.2C. Thats 1C below record high.  6.5C DP with WSW winds of 6km/hr


At Arctic bay which is accross the NW passage from Resolute is 15.2C with a 7.5C DP and WSW of 8km/hr.


The conditions throughout the CAA are absurd.


EDIT:. RESOLUTE IS NOW 19C with a 10.5C DP and SE WINDS OF 22KM/HR!!

THAT'S SILLY... ITS CLOUDY NOW.  BUT ID BET THE NW PAGE PASSAGE ICE STRAIGHT SHATTERS AND STARTS TO DECINTEGRATE.
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werther

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Re: The 2020 melting season
« Reply #3695 on: July 25, 2020, 11:41:37 PM »
And so ECMWF has the Storm back on T+72 hours...and now near 970MBar. Excited to see it unfold, but sad in what it will mean in the long run.

Csnavywx

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Re: The 2020 melting season
« Reply #3696 on: July 25, 2020, 11:46:16 PM »
At this pace, the CAA will melt out just a few days behind 2012 -- pretty exceptional considering how far behind it started.

Finally starting to see some mean reversion wrt extent and area. Area should continue to drop pretty quick, but with cross polar flow in the opposite direction from previous, extent may take a bit of an extended pause before in-situ melt starts hammering it again.

Csnavywx

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Re: The 2020 melting season
« Reply #3697 on: July 25, 2020, 11:55:35 PM »


EDIT:. RESOLUTE IS NOW 19C with a 10.5C DP and SE WINDS OF 22KM/HR!!

THAT'S SILLY... ITS CLOUDY NOW.  BUT ID BET THE NW PAGE PASSAGE ICE STRAIGHT SHATTERS AND STARTS TO DECINTEGRATE.

Yeah, the temps up there have been remarkable since about late June. This is the hottest wave yet.

Aluminium

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Re: The 2020 melting season
« Reply #3698 on: July 26, 2020, 12:05:49 AM »
Latest GFS predicts 970 mb. 30 hours below 980 mb.

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Re: The 2020 melting season
« Reply #3699 on: July 26, 2020, 12:22:37 AM »
One see thing I've noticed on the euro from last night and today the vortex while strong...iirc it drops under 975mb for a short time.

The question is...

WHERE IS THE COLD???

THE COLD POOL ASSOCIATED WITH THE LOW PRESSURE REGION IS VERY WARM EXCEPT DIRECTLY UNDER THE CORE.

EVEN THERE SURFACE TEMPS DON'T REALLY DROP BELOW FREEZING.

AND REMEMBER THE ICE FEEEZES AT -1.6 TO -1.8C.

 So even if temps do reach 0C or a modest -0.5C there will still be SURFACE melt.

Also for 3 days the vortex is between 972mb to 990mb.  It will be windy and rainy.

Nasty.

By day 9-10 the 00z euro develops another mega ridge.

The 12z euro is a lot more modestly warm but still bad.



Overall:. I would expect losses to drop down the next week to slightly below normal.

Could be normal or above if the Beaufort/WCAB start to fully open up
I got a nickname for all my guns
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and a dirty pistol that love to crew hop
my TEC 9 Imma call T-Pain
my 3-8 snub Imma call Lil Wayne
machine gun named Missy so loud
it go e-e-e-e-ow e-e-e-e-e-e-blaow