The 2018 melting season

[uniquorn]

Kara Sea. Land fast ice turning blue jun8-9. Wind blown slush at the ice front.

Worldview terra/modis true color, no enhancement

[ArcticMelt1]

Miracles! At 16-00 in Khatanga already +29.1С.

This is the maximum value in the meteorological annals of Khatanga from 1928 until June 18 (June 18 2014 was +32.9С).

Let's wait for the maximum temperature value today in Khatanga (June record in Khatanga - June 18 2014 was +32.9С).

[Neven]

This Earther journalist is paying attention:

A New Arctic Cyclone Could Be Among the Most Powerful On Record



Weather watchers may be more preoccupied of late with storms popping off in the Gulf of Mexico and the eastern Pacific, but a very unusual cyclone also spun up over the Arctic this week—and it could spell more bad news for the region’s ailing sea ice.

The Arctic is no stranger to cyclones, but the latest no-name storm, which emerged in the Kara sea north of Siberia, has garnered attention both for its size and timing. The storm’s central pressure (a measure of its strength) bottomed out Thursday at about 966 millibars, placing it par with the Great Arctic Cyclone of 2012, one of the most extreme summertime storms in recent memory. That storm reached a minimum central pressure 963-966 millibars, depending on which analysis you trust.

The new storm’s occurrence in June is also noteworthy. Big cyclones like this don’t normally start hitting the Arctic until late summer. The Great Arctic Cyclone of 2012 spun up in August as did a major storm in 2016.

“Preliminarily, this storm could rank in the Top 10 for Arctic Cyclones in June as well as for the summer (June through August) in strength,” Steven Cavallo, a meteorologist at the University of Oklahoma, told Earther via email.

Xiangdong Zhang, a scientist at the International Arctic Research Center who specializes in Arctic cyclones, cited a few factors responsible for the storm’s formation, including low sea ice cover in the North Atlantic which has increased the amount of heat in the atmosphere, a strong temperature gradient between land and sea, and the stratospheric polar vortex, an area of low pressure just above the storm.

“The downward intrusion of this polar vortex intensified [the] storm,” Zhang told Earther via email.

Read the rest here.

[Nikita]

Miracles! At 16-00 in Khatanga already +29.1С.

Tomorrow we will see 29C too.

Last record for June 9 was 18.7C. Now the difference is more than 10С.

[F.Tnioli]

This Earther journalist is paying attention:

...

“The downward intrusion of this polar vortex intensified [the] storm,” Zhang told Earther via email.

...

I mentioned the discovery of polar vortex' behaviour well matching equations which describe traffic jams, couple pages ago or so. When it's stuck, part of it goes "other ways", much like (some) cars do when trying to circumvent jammed area through any kinds of small roads around the jam. If the jam persists, more and more cars will try to "go around" it. Means, such storms may repeat in numbers frequently, one after another, if/when vortex gets seriously "jammed".

[Pagophilus]

Kara Sea. Land fast ice turning blue jun8-9. Wind blown slush at the ice front.

Worldview terra/modis true color, no enhancement

So the area of blue ice now extends continuously from the Laptev to the Kara (although not yet into the ESS).  Interestingly, that very long, narrow, winding gap seems to have recently opened from the Laptev to, perhaps, Franz Josef Land (see Worldview image below). Seems to be along the fast ice boundary.  Any significance?

(Later edit:  I see from Uniquorn's AMSR2 Hamburg animation below that this long gap has been there for a while and is just wider right now)

As noted by Frivolous it is currently sunny along the Siberian coast and looks set to continue to be so, just as this drop in ice albedo occurs.  5 day outlook from Climate Reanalyzer looks merciless.  The Laptev looks really vulnerable, both in terms of its current condition and the forecast.  Clouds still obscure much of the Kara, so full effects of the cyclone still unclear.

[oren]

Firstly, apologies for no pictures/animation - I'm in China and having difficulties with uploads!

Worldview: Has anyone noticed the rapid melting in the Amundsen Gulf (western CAA) over the past couple of weeks? Large chunks break off and then rapidly diminish. Some of it is getting swept out into the Beaufort, but it's getting a lot smaller on the way. My impression is that the Beaufort ice is rapidly losing density, as well; there's a lot of ice disappearing around there at the moment.

I know, it's June, you'd expect all that... just thought it was worth mentioning.

Scrolling through Worldview I certainly agree. A lot of the ice is swept against the eastern shore and then just disappears in that jumble. A lot of melting going on there.


On another issue, to those wondering about the recent "slowdown" in area losses, compared to expectation about the storm and Siberian warmth, I believe part of the explanation is a small uptick in CAB area which stems from fresh movement of the ice front from towards Svalbard, which I believe is an effect of the storm. Short term it increases the ice through export, longer-term this ice will be lost much quicker than if it had stayed stationary.

Note: this can also be seen in Wipneus' diff image which shows lots of internal losses but extra ice on the Svalbard front, on the data thread

[Pagophilus]

This makes complete sense to me.  I had prepared this comparison shot of AMSR2 images from June 3 and June 7 extent in the Kara/Barents area, but I was not sure if it would be of use at the time.  Perhaps it helps illustrate this phenomenom.

On another issue, to those wondering about the recent "slowdown" in area losses, compared to expectation about the storm and Siberian warmth, I believe part of the explanation is a small uptick in CAB area which stems from fresh movement of the ice front from towards Svalbard, which I believe is an effect of the storm. Short term it increases the ice through export, longer-term this ice will be lost much quicker than if it had stayed stationary.

Note: this can also be seen in Wipneus' diff image which shows lots of internal losses but extra ice on the Svalbard front, on the data thread

[Pagophilus]

More reason to be concerned about the Laptev.  Climate Reanalyzer forecasts that the Laptev will will have MINIMUM 2m air temperatures significantly (circa +3C to +5C ) above freezing for the next five days, warmer than any other part of the Arctic ice cap. 

[uniquorn]

Uni-Hamburg amsr2 concentration map for Laptev and some of Kara/Barents for this melting season mar21-jun7(no data today).

Open water is often seen as prevailing winds and/or currents separate the more mobile sea ice from the land fast ice.

It is my understanding that amsr2 detects melt ponds as low concentration or open water at times. Other weather conditions may also be temporarily detected as low concentration ice. Examples of both can be seen in the animation.

[Pagophilus]

Thank you.  I am learning so much from the expertise and experience of you and others on this forum.

Uni-Hamburg amsr2 concentration map for Laptev and some of Kara/Barents for this melting season mar21-jun7(no data today).

Open water is often seen as prevailing winds and/or currents separate the more mobile sea ice from the land fast ice.

It is my understanding that amsr2 detects melt ponds as low concentration or open water at times. Other weather conditions may also be temporarily detected as low concentration ice. Examples of both can be seen in the animation.

[Hyperion]

Hyperion, maybe I have misunderstood something, but a conservative estimate of 100 million kg of ice melting per second is approximately 0.1 cubic km of ice per second.  That in turn would be 360 cubic km per hour, and 8640 cubic km melting per day.  There are currently about 19000 cubic km of sea ice in the arctic, so this would result in almost half the arctic sea ice disappearing in one day

No sorry, I threw a mind cog with ten seconds of mental arithmetic there. Forgot a cubic km is a gigaton not a gigakilo. Three orders of magnitude error. How embarrassing. Giggles.

[gerontocrat]

 Giggles.

Is there an emoji for giggles?

[Neven]

No sorry, I threw a mind cog with ten seconds of mental arithmetic there. Forgot a cubic km is a gigaton not a gigakilo. Three orders of magnitude error. How embarrassing. Giggles.

Hyperion, try to quote only the part you're replying to, and not have 4-5 embedded quotes as well. It takes up so much space.

[Hyperion]

Sorry, Nevz. I'm in a tent in the mountains, have only 6Watts of solar electrickeries, editing on this phones a bitch, and I just found out a serious troppy is incoming. Gotta armour up. Be layin low for a few days.Fixed anyhowz.

[Neven]

Sorry, Nevz. I'm in a tent in the mountains, have only 6Watts of solar electrickeries, editing on this phones a bitch, and I just found out a serious trippy is incoming. Gotta armour up. Be layin low for a few days.Fixed anyhowz.

I understand, no problem. 

ECMWF remains interesting, with high pressure - though not very high - taking over again. Hudson Bay doesn't show on this D1-D6 image, but there's a high pressure system right over it for the entire forecast, so expect some drops there:

[aperson]

June 9th with IR overlay from the 272.8-273.4K bucket (-0.35C - 0.25C) to the 292.9-293.5K bucket:



Image link: https://i.imgur.com/JBObPzi.gif
Worldview link: https://tinyurl.com/yb6kf9vn

[subgeometer]

The Lena delta to June 9.

With the trend to deeper snow in the far north will the peak flows from rivers like the Lena get even greater, especially if a huge heatwaves comes in early June to melt it all at once, like this year

[Pagophilus]

I tried to get information from Worldview but am left guessing here (my fault, not yours).  Can I assume this image shows black-body IR from the Earth?  (I can see from the Worldview scale and the data itself that red values are close to 273K and more orange values represent higher temperatures.  And I can guess strange diagonal lines of discontinuity are results of different passes of the satellite.)  In cloud-free conditions, is this the best method of analysis of temperature?  Is it tricky to interpret?  Are the other surface temperature maps mostly interpolated from this data?  It seems to me that, among many things, this is a great tool to detect ice that is either melting or about to melt. 

 

June 9th with IR overlay from the 272.8-273.4K bucket (-0.35C - 0.25C) to the 292.9-293.5K bucket:

[aperson]

I tried to get information from Worldview but am left guessing here (my fault, not yours).  Can I assume this image shows black-body IR from the Earth?  (I can see from the Worldview scale and the data itself that red values are close to 273K and more orange values represent higher temperatures.  And I can guess strange diagonal lines of discontinuity are results of different passes of the satellite.)  In cloud-free conditions, is this the best method of analysis of temperature?  Is it tricky to interpret?  Are the other surface temperature maps mostly interpolated from this data?  It seems to me that, among many things, this is a great tool to detect ice that is either melting or about to melt. 

Yes, this is using the brightness temperature band from Suomi / VIIRS which uses longwave IR. This will show the cloud top temperature (and by proxy the cloud top height) in cloudy environments, and the surface temperature in cloud free environments.

It is good to see which ice is thinning as well as the surface temperatures of water. For example, the Lena River delta in the above image is extremely warm. In tandem with subgeometer's animation above we can get a qualitative understanding of discharge rate and total thermal energy of the delta.

Suomi / VIIRS and MODIS both perform multiple passes and stitch images together. Discontinuities occur along these lines. However, the IR and True Color imagery should be from essentially the same time on each section, so the overlay should match up with the underlying truecolor rendering.

[Pagophilus]

Nice image sequence.  I've read up some on this (this is a rare area where I can imagine I have some arctic expertise), so a few thoughts (maybe obvious to some of you, so forgive me). 

The Lena river is probably at or near full flood stage right now, but in past decades the river's water has been relatively cold at this time, maybe 2C or so.  Of course it is the heat delivered by the river that is the critical factor for melting ice.  Heat flow, historically, has been much greater in July than in June in the Lena.  This is largely because the June waters come from snowmelt and they then flow through a cold Siberia.  This year, as you state, most of the Lena's catchment area is already melted out.  If the period of maximum heat flow arrives earlier because of these anomalously warm conditions (and the Lena river flows, as you suggest, at higher volume), then it is going to be bad for the Laptev.  aperson's IR image and comment suggests this might already be starting.   

I am trying to get my head around how perilous a massive sheet of buoyant, warm fresh water is for any sea ice it meets.  BTW, I gather much of the Lena's waters usually flow from the Laptev towards the ESS to continue their melting mission there.   

The Lena delta to June 9.

With the trend to deeper snow in the far north will the peak flows from rivers like the Lena get even greater, especially if a huge heatwaves comes in early June to melt it all at once, like this year

[Pagophilus]

Thank you!

Yes, this is using the brightness temperature band from Suomi / VIIRS which uses longwave IR. This will show the cloud top temperature (and by proxy the cloud top height) in cloudy environments, and the surface temperature in cloud free environments.

[Pagophilus]

No sorry, I threw a mind cog with ten seconds of mental arithmetic there. Forgot a cubic km is a gigaton not a gigakilo. Three orders of magnitude error. How embarrassing. Giggles.

No worries.  Now we've cleared this up the Earth seems a safer place to me, and that doesn't happen often these days...

[subgeometer]

Wow, the airmass coming in over the Laptev is so warm, the whole region will stay WELL above freezing at 900hPa (around 900m altitude)for the whole forecast period. At the point marked it will remain above 10C into Wednesday, mostly 12 C or more. Later it briefly drops to near zero, but then rerturns to values around 6-8C, though that's too far off to have faith in.

The first few days have to be very bad for ice, what rate of ice thinning do they imply?

[subgeometer]

Thanks Pagophilus and aperson.

The ECMWF model (as displayed by WindyTv) shows above freezing surface water temps around the Lena delta as well as in the Laptev bite. I guess some of that can be attributed to the inflow from the river?

edit: added the attachment I forgot to post initially

[subgeometer]

The ice north of Svalbard has also copped a beating recently.

Its been cloudy, so I monkeyed with the levels of 2 worldview images from June 9 and June 6 to bring out the floes through the clouds. The earlier image shows the smooth melting edge zone that has been sitting just north of 82N for a while. On June 9 we see much of that 50+km wide strip has been reduced to tendrils of melting slush as it was pushed south, increasing extent temporarily, and paradoxically

technical note: in levels(in Gimp, but another editor would be the same) I pulled the black point in to 25, white to 234 and moved the grey point way towards white to 0.32

[Nikita]

Air temp.

[Pagophilus]

So aperson got me educated and interested in the IR images of the Lena delta.  I discovered that you can get the 'actual' temperatures by clicking on a point -- such a wonderful analytical tool.  So I started clicking on the Lena river channel itself and I found (I hope and assume) the surface water temp of the river water at that point. 

The Lena river gets colder as it flows north (this is counterintuitive to some degree as most rivers we know get warmer towards their mouths).  Right now, from these data, the river is already a toasty 11-12 C around 500km upstream of the delta, it is about 6-8 C as it enters the delta, and then, significantly, most of those tiny channels in the delta currently hold water that is between about 1 C at just before they exit into the sea. ((Later edit: if I had not had coastlines 'on' on Worldview when I originally looked at the delta, I would have been able to see many of the smaller channels were still frozen over ... duh!))   Two exceptions: the farthest east channel (top of picture) is the broadest of the Lena delta channels, and that water that registers as about 5C as it exits into the sea, but that channel exits into a peculiar area mostly enclosed by a spit of land and that area is still covered by sea ice. Puzzling to me -- is the rate of water flow really slow in this channel?  And the westernmost channel, broader than most, has water registering about 5C as it enters the sea, and is showing some initial melt-out at its mouth. 

So, one possible interpretation of these data is that the pulse of summer heat flow is coming down the Lena river, but it has not fully hit the Laptev Sea yet.  That would in turn explain why there has been so little melting (yet) of ice at the edge of the delta where it meets the sea ice.  Interesting days ahead, as the main pulse of heat flow arrives...

Lena delta image below is from today, June 10.


 

Thanks Pagophilus and aperson.

The ECMWF model (as displayed by WindyTv) shows above freezing surface water temps around the Lena delta as well as in the Laptev bite. I guess some of that can be attributed to the inflow from the river?

edit: added the attachment I forgot to post initially

[Pagophilus]

Great image work, subgeometer.  It seems to me that there are thicker floes that were present before and survive after in that mass of melt, so is the melting slush is from younger, thinner ice?  And if so, are the tendrils of melting slush from first year ice that once 'united' the floes, or from spring refreeze ice?

The ice north of Svalbard has also copped a beating recently.

Its been cloudy, so I monkeyed with the levels of 2 worldview images from June 9 and June 6 to bring out the floes through the clouds. The earlier image shows the smooth melting edge zone that has been sitting just north of 82N for a while. On June 9 we see much of that 50+km wide strip has been reduced to tendrils of melting slush as it was pushed south, increasing extent temporarily, and paradoxically

[Aluminium]

So, one possible interpretation of these data is that the pulse of summer heat flow is coming down the Lena river, but it has not fully hit the Laptev Sea yet.  That would in turn explain why there has been so little melting yet of ice at the edge of the delta where it meets the sea ice.

Firstly, Lena brings to Laptev large amount of river ice and cold fresh water. Ice flow finished couple of days ago. Before this moment, incoming water has no chance to warm significantly.

[uniquorn]

Animation of Lena delta jun8-10 with VIIRS brightness temperature overlayed. Sun, warm water and winds raise the temperature over the three relatively cloudless days.
Light blue ~1C to yellow ~18C

Ice melt in the Laptev surrounding the delta may accelerate, but PIOMAS indicates ice in that area 10 days ago was ~2m thick. Things have obviously changed a lot in the last week though.

My mistake, I was looking at an earlier chart. PIOMAS indicates ice there is mostly less than 1m thick

[bbr2314]

Animation of Lena delta jun8-10 with VIIRS brightness temperature overlayed. Sun, warm water and winds raise the temperature over the three relatively cloudless days.
Light blue ~1C to yellow ~18C

Ice melt in the Laptev surrounding the delta may accelerate, but PIOMAS indicates ice in that area 10 days ago was ~2m thick. Things have obviously changed a lot in the last week though.

I think ^^^ verifies the notion that PIOMAS is increasingly wrong.

Also: SSTs/etc show that the plume of warm Atlantic water entering the Arctic N of Svalbard is about to juice tremendously over the next few weeks. It looks like we may see a rapid retreat of the melt front towards the North Pole now that the GAC has unified the front from Svalbard all the way to Laptev? (if you compare before/after you can see what I mean by this, specifically over the NRN Kara/Barents)

Simultaneously, the Beaufort is now turning into a mass of floes vs. anything coherent. As the thinner FYI melts out over the next 10 days area #s should begin to drop precipitously.

[bbr2314]

Also: this May was actually much more impressive than 2012 in terms of High Arctic heat import. The oceans are way warmer and while the land-albedo feedback is now apparently kicking into high gear over places like Quebec, that acted like an enormous vortex, coupling with Atlantic SSTs/etc to suck heat N over Africa and Europe and directly into the Arctic.



June is a bit cooler so far but the anomalies are positioned differently. I would think 2018 will blaze much brighter as well after the next few days are added.

[uniquorn]

Ice melt in the Laptev surrounding the delta may accelerate, but PIOMAS indicates ice in that area 10 days ago was ~2m thick. Things have obviously changed a lot in the last week though.

I think ^^^ verifies the notion that PIOMAS is increasingly wrong.
<snippage>

My mistake, I was looking at an earlier chart. PIOMAS indicates ice there is less than 1m

[bbr2314]

I think a look at HYCOM also opens the possibility of something very odd happening this year: an actual major split in the multi-year ice!

A look at 2016's map on 7/1 shows how that year came close to seeing ^ happen. The difference with 2018 is that this year's ESS ice is much thicker, the ice linking it to the CAB is seemingly much thinner, and to date, there seems to be some anchoring effect where the ESS ice has remained stubbornly in place.

With the amount of thick ice in far-off places, it is not inconceivable that the Kara is the first region to be divided from the general Arctic ice mass. Then the ESS may follow in a rather more dramatic fashion as the thin ice between Laptev and Beaufort/Chukchi "unzips" as the increasing lack of land-fast tension allows the sheet to separate into increasingly small floes.

I would think that if this happens it will increase proclivity for severe cyclonic activity as an increased number of snow-ice-water gradients probably multiply the vectors for generating/sustaining cyclones as compared to stable and unified fronts. Perhaps this is also why, with all the newly open water in Laptev/Kara, we saw a cyclone follow rather quickly.

[bbr2314]

...and funny enough the latest Slater projection shows a rough approximation of ^ happening by 7/30, with Hudson, Kara, and ESS holding strong while the ice linking Laptev/Chukchi/Beaufort comes under immense stress & melt:

[Hyperion]

And now our Beaufort cyclone, not happy with the quality of the European water,  is about to start feeding on a new feast, arriving on a fast North American train, straight from the gulf of
Mexico. Coming in over the McKenzie catchment also!

[A-Team]

Early June actually saw two unusually disruptive storms. The first swept down from eastern Siberia past Banks Island, leaving a broad swath of melting temperatures (and likely rain) that obliterated long-standing Ascat roughness features beginning on June 2nd (frame 36 vs 37; 12 hour AB resolution).

The second was the later cyclone being discussed above; it wiped Ascat (and Jaxa) features northward of FJI. Loss and change in features makes it much more difficult to track advection of ice to warmer seas, though some Fram export has resumed. (Magenta arrows in the Osi-Saf drift mean uncertainty.)

Overall, there is no good way to immediately measure impacts of events such as these, as this early in the season measures such thickness, area, extent, concentration may not notably respond during the events even though the ice is being seriously preconditioned.

The notion of comparing storm vs no-storm seems problematic given lack of a physically relevant control (weather for no-storm?). Comparing a storm in early June to a storm in early August of a different year is beyond problematic. And saying 'it was going to melt out anyway' is not the answer because an early date of loss has many downstream consequences lacking later in season. Even looking back from mid-September, attribution will not be an easy matter

[RoxTheGeologist]

I am trying to get my head around how perilous a massive sheet of buoyant, warm fresh water is for any sea ice it meets.  BTW, I gather much of the Lena's waters usually flow from the Laptev towards the ESS to continue their melting mission there.   

Quick back of the envelope:

Lena peak flow is 80,000 m3 per second, at 2°C, that has the energy to melt 2000 m3 of ice. So at the peak discharge it takes around 10 minutes to discharge enough water to melt 1 km 2 of ice 1 m thick. It can melt something like 144 km 2 a day. The latent heat of fusion of ice soaks up A LOT of energy.

It contributes a small fraction to the daily melt change.

[Pagophilus]

I am not disputing your points in any way, nor do I doubt you personally in the slightest (in fact I avidly read your comments) but I believe the Slater projection maps are misleading and maybe close to intellectually dishonest.  As far as I can tell these projections are differently colored versions of the latest sea ice concentration maps (as per the NSIDC map in the image). Once different and prettier colors are applied to the data set, then a different scale is applied to the side.  Sea ice concentration that is perhaps now around 70% is ascribed a value of maybe 20%. And voila! The latest Slater Probabilistic Sea Ice Extent prediction for July 30!  Or some similar process.

If you don't believe me, please look at the images below.  The current ice extent on the Slater graph,once you look to its edges, is just a little inwardly displaced from today's ice distribution  And then look at the image on the right, for the actual distribution of ice last year on July 30.  There is almost zero probability that there will be significant ice in Hudson Bay, the south/west Kara Sea and Baffin Bay on this coming July 30.  But the Slater map has ice in all these places, because that is where 100% ice concentration exists right now. Other examples abound.  Hey, even I could do better than this! 

I know that I am but a lowly Lurker, but scientifically I think one of the worst things we have to deal with are grossly misleading methodologies or analyses.  These Slater maps seem to fall, perhaps inadvertently, into this category.  I leave it to others to decide, but is it worth Wipneus, Neven, oren and other notables discussing whether these projections should even appear on these forums?  BTW I believe these projections were once very good, but that Dr./Mr. Slater passed away -- I do not want to blemish his name in any way.

...and funny enough the latest Slater projection shows a rough approximation of ^ happening by 7/30, with Hudson, Kara, and ESS holding strong while the ice linking Laptev/Chukchi/Beaufort comes under immense stress & melt:

[Greenbelt]

My next area to watch on worldview is the East Siberian Sea, which seems a bit behind in melt preconditioning compared with some recent years. ECMWF and GFS initialize a 1030mb high over far eastern Siberia, which should continue the clear skies and bring in southerly winds and probably finish off the land-based snow. I'm interested to see how fragile this area is.

[uniquorn]

Early June actually saw two unusually disruptive storms. The first swept down from eastern Siberia past Banks Island, leaving a broad swath of melting temperatures (and likely rain) that obliterated long-standing Ascat roughness features beginning on June 2nd (frame 36 vs 37; 12 hour AB resolution).
<snippage>

A similar event appears to have happened in 2016. Ascat day126-160.
May5-Jun8 2016

edit: I checked 2012 day132-160, and 2015 (neither are shown) which also show a similar feature loss. (I haven't checked all years)

[bbr2314]

Early June actually saw two unusually disruptive storms. The first swept down from eastern Siberia past Banks Island, leaving a broad swath of melting temperatures (and likely rain) that obliterated long-standing Ascat roughness features beginning on June 2nd (frame 36 vs 37; 12 hour AB resolution).
<snippage>

A similar event appears to have happened in 2016. Ascat day126-160.
May5-Jun8 2016

edit: I checked 2012 day132-160, and 2015 (neither are shown) which also show a similar feature loss. (I haven't checked all years)

I think something different this year is that the Laptev ice has detached/disappeared completely while the ATL front is far more advanced as well. It is like the entire sector has rapidly "Atlantified". The same is occurring re: Pac water in Chukchi/Beaufort (IMO).

I would think that though they may be somewhat similar on the surface the impact so far in 2018 has been much more substantial because of the ice's pre-existing condition under the snow (i.e. very fragile/then frazile).

Another important contrast with prior years (2012 especially) is the status of lower-latitude continental snowcover, which remains elevated, and is apparently acting in tandem with the oceanic heat to fire blasts of mid-latitude heat upward and into the Arctic. I would think this helps explain why May's temperature anomalies over the High Arctic were substantially more positive than 2012, despite 2012's horrible snowcover #s.

[bbr2314]

I am not disputing your points in any way, nor do I doubt you personally in the slightest (in fact I avidly read your comments) but I believe the Slater projection maps are misleading and maybe close to intellectually dishonest.  As far as I can tell these projections are differently colored versions of the latest sea ice concentration maps (as per the NSIDC map in the image). Once different and prettier colors are applied to the data set, then a different scale is applied to the side.  Sea ice concentration that is perhaps now around 70% is ascribed a value of maybe 20%. And voila! The latest Slater Probabilistic Sea Ice Extent prediction for July 30!  Or some similar process.

If you don't believe me, please look at the images below.  The current ice extent on the Slater graph,once you look to its edges, is just a little inwardly displaced from today's ice distribution  And then look at the image on the right, for the actual distribution of ice last year on July 30.  There is almost zero probability that there will be significant ice in Hudson Bay, the south/west Kara Sea and Baffin Bay on this coming July 30.  But the Slater map has ice in all these places, because that is where 100% ice concentration exists right now. Other examples abound.  Hey, even I could do better than this! 

I know that I am but a lowly Lurker, but scientifically I think one of the worst things we have to deal with are grossly misleading methodologies or analyses.  These Slater maps seem to fall, perhaps inadvertently, into this category.  I leave it to others to decide, but is it worth Wipneus, Neven, oren and other notables discussing whether these projections should even appear on these forums?  BTW I believe these projections were once very good, but that Dr./Mr. Slater passed away -- I do not want to blemish his name in any way.

...and funny enough the latest Slater projection shows a rough approximation of ^ happening by 7/30, with Hudson, Kara, and ESS holding strong while the ice linking Laptev/Chukchi/Beaufort comes under immense stress & melt:

I believe you are mostly correct however I also believe Slater's model does have some predictive capacity if you acknowledge its biases. We shall see!

[A-Team]

SMOS thin ice is also a mixture of transient storm artifacts (not really sub 0.5 m in the central Arctic) and possibly good data around the periphery (look for multi-day consistency). The physical basis of enhanced dielectric may be surface salt dissolving in rain/melt.

AMSR2 is still making good sense: dropping concentration in the expected places. The Laptev and Kara flaw polynyas have been, to this point, primarily wind driven. However their very size sets off feedbacks that enlarge them without wind.

[uniquorn]

I think something different this year<snippage>

Sorry, I should have been clearer. I had hoped to point out that various weather events around this time of year may make it more difficult for ascat to pick out previously clearly identified roughness features.
I agree that every year is different.

[bbr2314]

SMOS thin ice is also a mixture of transient storm artifacts (not really sub 0.5 m in the central Arctic) and possibly good data around the periphery (look for multi-day consistency). AMSR2 is still making good sense. The Laptev and Kara flaw polynyas are, at this point, primarily wind driven. However their very size sets off feedbacks that will enlarge them without wind.

The latest images look like the GAC did indeed act as an enormous hot sledgehammer. I think it is less of a transient storm artifact and more of a rapid transition to extreme/abrupt melt. The same that occurred NE of Svalbard over the period of the animation ^.

The flash-melt of previously abundant ice-snowcover we have seen should be sufficient to raise albedo substantially. The polynyas will allow for dispersion to occur as well, as land-fast tension is now mostly gone. The weather forecast for the next several days+ is bleak and SMOS maps should only get worse.

It looks like we will see the Pacific front actually advance toward Bering over the next week if HYCOM is to be believed, as this shift in tension/etc allows the ESS/Chukchi ice to hold fast to Asia.

I suppose the essence of ^ is a question: are we at a point where there has been enough heat accumulated in the High Arctic early enough in the season so that Coriolis Forcing will overcome an increasingly incoherent pack to shatter the high ice into disjointed land-adjacent agglomerations instead of a coherent whole centered on the CAB? Note, the thickest ice is now adjacent to Siberia or the CAA islands, Beaufort's MYI is effectively all gone.

If this occurs, does it 1) disprove the notion that a truly "Blue Arctic" is possible, while simultaneously 2) worsening the impact of abrupt climate change, with an increasing numerical quantity of source regions for polar vortices prone to generating rapidly-mounting continental snowfall?

We shall see...!

[A-Team]

weather events around this time of year may make it more difficult for [microwave] to pick out previously identified features.

Did you have a chance to animate nullschool over this time frame? Editing the url will set the clock back to 2016. Some browsers have an add-on that will open a huge list of links and save out the contents as frames.

https://earth.nullschool.net/#2016/06/01/0000Z/wind/isobaric/1000hPa/overlay=mean_sea_level_pressure/stereographic=-45.00,80,2400/loc=180.00,80.00

rapid transition to extreme/abrupt melt

SMOS will probably settle back down over the next few days. However in the middle of an event, the two scenarios are difficult to distinguish. Note SMOS etc lag by a day whereas Worldview gives a peak ahead to near-real time, the June 10th below will open to 2x the size shown.

The ice today is in a fairly delicate balance. In the not so distant past (MIS 6 ~140 ka), the floating ice shelf was over 1000 m thick and dragging its keel across the Lomonosov Ridge., leaving ice scours still observable today.

https://phys.org/news/2018-04-arctic-ocean-ice-shelf-size.html April 2018
https://www.nature.com/articles/s41467-018-03707-w free full text
https://www.nature.com/articles/ncomms10365  2016 free full text

[uniquorn]

Did you have a chance to animate nullschool over this time frame?

Thanks for this. I'll check back to 2014 and see if there is any correlation.

[Pagophilus]

I believe you are mostly correct however I also believe Slater's model does have some predictive capacity if you acknowledge its biases. We shall see!

Fair enough.  You know more than I do, you have found the model of use, and I truly respect that.  And we shall indeed see. 

But ... I'd just like to state that the Slater model for July 30 predicts at present that almost all of the CAB in terms of its current margins has an 80% chance of remaining intact, except there is a 50% chance that a colossal flattened gap will for some reason open up in the middle of the CAB.  The Slater model also predicts with 80% probability that all the ESS, the eastern third of the Laptev, all of the southern Kara, and half of Hudson Bay will be ice-bound on July 30. 

The Pagophilus Probabilistic Model (which runs on KommonSenz 2.0) predicts with 90% probability that almost none of this will come to pass.