The 2021 melting season

[Jim Hunt]

Jim Hunt, thank you (and Snow White) for the 1000mb temp charts. This is not exactly as I have envisioned which is a replication of the DMI chart

Our pleasure Oren. That is what I erroneously assumed would be possible. As far as I can tell WRIT only permits a daily time series to be produced for a single grid cell, not for an area containing several grid cells.

If anybody works out a way to do that please let me (and Snow) know ASAP!

[Jim Hunt]

The “big block” of sea ice I’ve been watching on its journey through the Fram Strait has started breaking up:

https://GreatWhiteCon.info/2021/05/facts-about-the-arctic-in-may-2021/#May-11

[Glen Koehler]

NSIDC Data 10th May - a bit more

High Arctic sea ice area loss remains very slow.

While the Central Arctic Region sea ice area is at the HIGHEST in tye 43 year satellite record for a second day, the Kara is losing sea ice area fast. More a case of sea ice movement than melt?

Peripheral Seas sea ice area continues its somewhat leisurely decline.

    The joints in my catastrophist bones are aching and predicting that there are multiple 200K Extent loss days coming sooner than later.  Once the spreading slows and the May June sunshine and heat continues to grow there's gonna be a whole lot of shakin' goin' on, and I ain't fakin'.  Just my hunch.  Would be great to be wrong, but this cracked CAB, weak Atlantic front situation seems to be a setup for what comes next.

[Killian]

An observation.

Using the interactive JAXA chart, I noticed a few weeks ago this season seemed to be more variable than most. I've done a few preliminary comparisons before, but today I did a one-to-one comparison with every other year on that chart and, sure enough, 2021 is more variable than any other season, and it's by a lot - at least visually. (I haven't run any numbers for statistical significance.) Only 2013 is similar over the Winter time frame, but smooths out with the arrival of Spring.

Theory: The overall changes we've seen have left the ice more vulnerable to almost any kind of influence, thus more variability. E.g.:

* lower volume
* thinness
* reduced thick/older ice
* changes in where older ice is located
* fragility from leads throughout the ice pack in summer
* Etc.

All of this should be countered somewhat by the neutral correlation of La Nina's to low ASI, but this is a LN-influenced year and we are seeing the greatest variability in the record.

Year-to-year variability should continue to be expected, but I think we will see more variability, in general, moving forward - as I said some years ago. Undoubtedly many of you have said the same. I think we're here.

[Frivolousz21]

Here is 2020 versus 2021 for April


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The text data shows April 2021 the lowest thickness on cryosat records.

Slightly lower than 2013.

Clearly the big change is the thin band over the southern CAB

[Alphabet Hotel]

4.4 MB optimized GIF animation of false-color AMSR2 Arctic Ocean images

Date range 2021-04-24 thru 2021-05-11

Click to animate. Loops forever. Click again to zoom.

[uniquorn]

north greenland/pole high contrast for ref. A lot of shear posted by Uniquorn, amazing view not sure what satellite is used.

The processing is not too hard to replicate
Satellite was Terra/Modis from Worldview  https://go.nasa.gov/3hognpo (Cycle through all 4 sats to get the best cloud free image)
250m snapshot, format .png
Drag into ImageJ
Image->Adjust->brightness/contrast (103,255 for high contrast, depends on histogram)
Process->enhance local contrast (127,256,2.3)
Image->scale (forum has a pixel size limit so 0.5)
File->Save As-> jpg (to keep file size small)

[Jim Hunt]

Here is 2020 versus 2021 for April

Welcome back Friv!

See also the mid April reanalysis from AWI. Also note that CS2/SMOS has a negative anomaly in the Beaufort Sea, where PIOMAS has a positive anomaly:

https://GreatWhiteCon.info/2021/05/facts-about-the-arctic-in-may-2021/#May-10

[Aluminium]

5-day average anomaly, max temperature, average winds. Winds clearly work against the ice. Temperatures are rising to nearly zero, 4-10°C above normal with little cold areas. Some rain is also forecasted on Siberian side. Further forecasts are warm and anticyclonic. Too soon for potential retention. I would expect medium to strong melting season. 5+ day forecasts are not reliable though.

[glennbuck]

The processing is not too hard to replicate

Thanks Uniquorn is a nice bit of free software Fiji, imageJ.

May 12, clear view from the Atlantic side. North Greenland up to FJL.

[Jim Hunt]

Jim Hunt, thank you (and Snow White) for the 1000mb temp charts. This is not exactly as I have envisioned which is a replication of the DMI chart (annual chart showing daily values of 2m temps) but is very useful.

Still no joy at this end with WRIT. However what you require should be eminently feasible using the python programming techniques outlined at:

https://forum.arctic-sea-ice.net/index.php/topic,1871.0.html

However I'm spending far too much time over on the "dark side" just at the moment to attempt the task myself.

[Jim Hunt]

May 12, clear view from the Atlantic side. North Greenland up to FJL.

Which permits a nice view of the remaining pieces of my favourite "big block" heading out into the warm waters of the far North Atlantic:

[Shared Humanity]

The processing is not too hard to replicate

Thanks Uniquorn is a nice bit of free software Fiji, imageJ.

May 12, clear view from the Atlantic side. North Greenland up to FJL.

To my very nonexpert eye, that does not look good.

[Shared Humanity]

May 12, clear view from the Atlantic side. North Greenland up to FJL.

Which permits a nice view of the remaining pieces of my favourite "big block" heading out into the warm waters of the far North Atlantic:

The big block is maintaining a fair degree of integrity as everything around it melts into wisps of debris. Does this suggest it is a fairly thick block of ice, perhaps MYI?

[Freegrass]

Latest Five Day Forecast + Last 48h
Wind + Temp @ Surface
Large GiF!

Positive temperatures are coming in...

[Sublime_Rime]

But really means nothing if  a big time CAB ridge takes hold before the 10th of June.

I know its still a bit far out, but there is pretty strong GFS/Euro model convergence for the current dipole shifting into a pretty mean ridge by d6, and strengthening through d10. This accompanied by the positive anomalies others have been posting about in the CAB, may lead to some serious early preconditioning, imho.

[Aluminium]

Another sign is snow cover extent anomaly.

May 5 ... -98 506 km²
May 6 ... -55 268 km²
May 7 ... -1 063 269 km²
May 8 ... -1 362 920 km²
May 9 ... -1 394 321 km²
May 10 ... -1 023 369 km²
May 11 ... -2 014 829 km²

https://cryospherecomputing.tk/

[glennbuck]

Arctic daily Sea ice area took a big drop today 133,000 km 2. Along with ice thickness around the same as 2020 in April record low 162.05cm. Will be interesting to see if thickness rises like last year for a few weeks more or continues up into June.. Is there an update on ice thickness for May?

[Jim Hunt]

I shall impart the good news first. ICESat-2 level 4 monthly gridded Arctic sea ice thickness data is available at long last! Please see:

https://nsidc.org/data/IS2SITMOGR4

The bad news? Currently it's only available from 1 November 2018 to 30 April 2020 

P.S. There also seems to be an absence of data in summer

[Jim Hunt]

Does this suggest it is a fairly thick block of ice, perhaps MYI?

That is indeed my assumption also.

[Jim Hunt]

I know its still a bit far out, but there is pretty strong GFS/Euro model convergence for the current dipole shifting into a pretty mean ridge by d6, and strengthening through d10.

Via Judah Cohen on Twitter:

https://twitter.com/judah47/status/1392486132181606406

More active troposphere-stratosphere coupling post a Final Warming is becoming increasingly interesting as relatively strong vertical energy transfer is predicted to warm the polar stratosphere with feedbacks on the troposphere.

And we can already see implications on our weather with building high pressure near the North Pole which would promote troughing and relatively cool temperatures in parts of Asia, Canada and Europe and would be hostile to Arctic sea ice and would likely accelerate melt.

[Pagophilus]

Another sign is snow cover extent anomaly.

May 5 ... -98 506 km²
May 6 ... -55 268 km²
May 7 ... -1 063 269 km²
May 8 ... -1 362 920 km²
May 9 ... -1 394 321 km²
May 10 ... -1 023 369 km²
May 11 ... -2 014 829 km²

https://cryospherecomputing.tk/

To add to this, much of the snow loss is taking place on the Asian side, with the current drops taking the snow extent loss close to 2 standard deviations from the mean for this time of year, and plummeting right now, as the figures quoted by Aluminium above show.  Attached graph, map from Nico Sun, via https://cryospherecomputing.tk/

[pearscot]

Well each year I feel like the Arctic is defined by *some* new attribute that is noticeable/noteworthy; last year were the persistent clear skies, this year I'd say the 'scaling' effect of the ice.  I went back thru and looked at all of the imagery dating back to 2000, and nothing really appears to match the current state of the ice, at least across such a substantial area (I'm speaking of the entire Atlantic front). Additionally, the Beaufort is beginning to have a similar appearance.

While extent is certainly not crashing at the moment, from my observations it appears as though the ice is being ripped toward the Atlantic and Pacific oceans with Atlantification allowing for increased bottom melt at a bare minimum. It's hard to articulate, but the summation of all these processes, in my opinion, is that the ice just looks like shit. It all looks weak and stressed with larger and larger gaps opening between the large chunks of sea ice. The wind also seems to really be aggressive out of the Fram Strait, though someone who's been here far longer than mine would know best.

Is ice export out of the Fram exceptionally high this year or average?

Anyways, I do now firmly believe it will be Atlantification that will be the ultimate demise of the ice (tho of course all other factors contribute). I can't wait to see how the season unfolds, but I think the Atlantic front is going to have a rough year. It's not like the water is below the long term average up north either.

[Freegrass]

HYCOM ice thickness model is showing a very different story. The thickest ice is located in the Beaufort according to HYCOM, and it also shows how thicker ice has moved towards the Atlantic side, stretching the ice in the center no doubt, with a lot of fractures as a result.

It's also still showing that weird hole in the ice, that is actually still growing. I think it's able to grow because the ice there isn't moving that much, and there must be an upwelling there I presume? It'll be interesting to see if that hole melts out and becomes visible.

I don't expect to see early open water in the Laptev - like we had last year - but there was some movement of the ice northward...

Thick ice is now also ready for it's exit through Fram strait. But if we don't get the weather for it, it'll probably remain there and protect the Atlantic front a little...

Fram export was very low this year Pearscot. The wind was blowing all the ice towards the Pacific side during winter. And so it's interesting how little volume there is with a wind pattern like that during the freezing season.....

Two places of interest for this melting season IMHO. The Atlantic front, and the Beaufort sea. Laptev and ESS shouldn't be that spectacular this year. Unless a big weather event comes around to mess it all up of course...

[Paul]

Well each year I feel like the Arctic is defined by *some* new attribute that is noticeable/noteworthy; last year were the persistent clear skies, this year I'd say the 'scaling' effect of the ice.  I went back thru and looked at all of the imagery dating back to 2000, and nothing really appears to match the current state of the ice, at least across such a substantial area (I'm speaking of the entire Atlantic front). Additionally, the Beaufort is beginning to have a similar appearance.

The Atlantic front is certainly interesting to observe, no idea what it will all mean though but as you alluded too, it could be the big noteworthy feature of this melt season.

I still suspect as the ice thins out, it will look more smoother and flatter but Atlantication could well be extreme again this year.

The Beaufort sea could get interesting soon, cold at the moment and whilst there is no significant warmth on the way, the winds will be blowing strong and pushing the ice away from the coastline.

[jdallen]

Another sign is snow cover extent anomaly.
...<SNIP>
May 11 ... -2 014 829 km²

To add to this, much of the snow loss is taking place on the Asian side, with the current drops taking the snow extent loss close to 2 standard deviations from the mean for this time of year, and plummeting right now, as the figures quoted by Aluminium above show.  Attached graph, map from Nico Sun, via https://cryospherecomputing.tk/

THIS I believe bears close watching.

There was considerable depth in the pack in Asia this winter.  It's all now crashing down the watersheds as the snow pack similarly crashes.

We have 2 million km2 more land surface now with 30-40% lower albedo, just as Northern Hemisphere insolation starts to shift into high gear.

Watch for hot, effectively blistering plumes of heat rolling north from Siberia over the Laptev and ESS.  I would not be surprised if we saw a heat wave with mid-20's along the coast by early June.

I would also love to see water temperatures at the mouth of the major estuaries.  That's heat transport straight out of the interior directly to the Arctic.

Time to start watching more closely.

The disappearance of coastal snow pack along those regions may suggest melt momentum straight on to the pack with the associated wide-spread development of melt ponds.

[romett1]

Latest Five Day Forecast + Last 48h
Wind + Temp @ Surface
Large GiF!

Positive temperatures are coming in...

Wind gust forecast between today and Saturday. As can be also seen from Freegrass post, new low is entering to the Arctic from the Laptev Sea on Saturday.

[uniquorn]

Time to start watching more closely.

The disappearance of coastal snow pack along those regions may suggest melt momentum straight on to the pack with the associated wide-spread development of melt ponds.

A casual overview of snow (and cloud) extent on may12 since 2000. No contrast changes. (5.3MB)

[Alphabet Hotel]

Today's false color AMSR2 image features the return of the Atlantic-side cracks.

I'll keep posting animations, but daily seems like too much.

[Freegrass]

I don't expect to see early open water in the Laptev - like we had last year - but there was some movement of the ice northward...

I need to correct this. The last storm opened up a huge 80km wide gap along the Severnaya Zemlya islands. If this remains open water, the ocean there will be able to soak up a lot of heat - like it did last year. So lets hope it closes up again. If not, the Atlantic front will be even more susceptible to rapid melting over the entire length...

[glennbuck]

Yes a very rapid change around  Severnaya Zemlya islands. May 13

[Aluminium]

Snow cover extent anomaly.

May 6 ... -55 268 km²
May 7 ... -1 063 269 km²
May 8 ... -1 362 920 km²
May 9 ... -1 394 321 km²
May 10 ... -1 023 369 km²
May 11 ... -2 014 829 km²
May 12 ... -2 697 511 km²

https://cryospherecomputing.tk/

[Pagophilus]

Snow cover extent anomaly.

May 6 ... -55 268 km²
May 7 ... -1 063 269 km²
May 8 ... -1 362 920 km²
May 9 ... -1 394 321 km²
May 10 ... -1 023 369 km²
May 11 ... -2 014 829 km²
May 12 ... -2 697 511 km²

https://cryospherecomputing.tk/

It may be time to fasten our seatbelts.  See jdallen's comment, Reply #525.  This is indicative of how quickly things have turned around in Siberia... NOAA in March showed a general negative temperature anomaly in the Kara-Laptev area of Siberia.  In April they showed a strong positive temperature anomaly developing, particularly around the Kara area.  It was an abrupt switch -- see below
 
Now it is mid May.  The above snow extent anomaly, which derives mostly from steep losses on the Siberian side, is a proxy indication that temperatures are continuing to rise unusually strongly there.  If these trends continue, then the Laptev, Kara and ESS, even with their extensive fast ice, may not look secure at all this season.  And the sea ice in these seas is in average condition at best, looking very rubbly in places.

https://www.ncdc.noaa.gov/sotc/global/202104.
   

[oren]

Wow, the snow anomaly change is astounding.
As jdallen said upthread, all this extra snow melted at once is going to flood into the Siberian seas soon.

[Pagophilus]

Wow, the snow anomaly change is astounding.
As jdallen said upthread, all this extra snow melted at once is going to flood into the Siberian seas soon.

And the Siberian land albedo is going to decrease dramatically, as jdallen also mentions.  The one consolation, sort of, is that this does not seem to be occurring uniformly across northern Siberia right now (neither in terms of temperature or snow extent anomalies), but is mainly centered around the Kara and western Laptev coasts...   Although the heat might be moving eastwards somewhat - see below  https://climatereanalyzer.org/wx/DailySummary/#t2anom

[glennbuck]

Scott Duncan over on Twitter posted this.

Exceptional heat. You would be able to stand and look over the Barents Sea in the Arctic Circle in shorts and shirt today.

https://twitter.com/ScottDuncanWX/status/1392862346406735872/photo/2

[RoxTheGeologist]

Wow, the snow anomaly change is astounding.
As jdallen said upthread, all this extra snow melted at once is going to flood into the Siberian seas soon.

Worst of both worlds - lots of early snow to trap summer heat in the ground, but without the benefit of high albedo later into the spring.

[uniquorn]

Some more export to the Barents. Bigger floes now heading for the exit. Wind forecast is similar for a couple of days.

worldview  https://go.nasa.gov/3fhJ7gN
rammb  https://col.st/HsFve (800kb)

[be cause]

Export continues apace between 0'E and 60'E . A lot of ice moved another 20km south today . The 'plates' of ice in this section remind me of a similar break-up of ice in Kara last year . That ice was gone in a month .
Even with all the mobility , this is the first year that there seems to be little or no thick ice with a deep keel (certainly not on the Atlantic side). Such ice tended to be slower to respond to changes in wind direction compared to any thinner surrounding ice and therefore was rather noticeable .
 
Considering the amount of snow this winter in Russia/Siberia it is shocking to see melt moving north so rapidly . Forecasts predict a lot of snow melt over the ice too .
 
Latest gfs forecast is the coolest recently .. but I would not be surprised to see the next one reverse this . Export looks like continuing for the rest of the month , hopefully at a slower pace . b.c.
 

[Paul]

For me, it's truly dissapointing yet not surprising too see how quick Siberian snow cover has melted, I thought seeing as things been significantly below average during February and March, it may of delayed any real significant heat/delay snowcover loss but certainly not the case. At least most of that heat won't be reaching the ice though, only crumb of comfort I can find.

[uniquorn]

Hopefully not overkill, here is Siberian snow cover this year, apr5-may13, large drops from may4 onwards. Rivers still mostly frozen though (on the surface) except the Ob

[pearscot]

Obviously I'm exaggerating, but I feel like this feature appeared almost overnight...I was actually shocked to see it today when I did my daily scan of new changes on Worldview.

I do appreciate everyone's posts lately, it's just really interesting to see this melt season begin. I have a sneaking suspicion that the wind is really causing some damage down there...especially with the scales of ice being pulled from the Arctic. I measured a few gaps and most are between 5-10km. I can tell you as someone who lives on an island, a 3 mile stretch of open ocean can certainly facilitate some large waves.

[Jim Hunt]

A lot of ice moved another 20km south today

My much loved "big block" has moved ~50km south from one WorldView frame to the next.

Dunno if that's exactly 24 hours or not, but it's still a long way!

[uniquorn]

A lot of ice moved another 20km south today

My much loved "big block" has moved ~50km south from one WorldView frame to the next.
Dunno if that's exactly 24 hours or not, but it's still a long way!

Drat. Your floe is bigger than mine Must be made of stern stuff to make it that far out.
You could try rammb, it has time stamps.

[Alphabet Hotel]

Lena river ice is starting to break up. There are clear traces further north and then there's this big opening:

[El Cid]

Aren't these April/May/June Siberian heatwaves starting to become a regular feature? I wonder why this happens. Coincidence or a change of atmospheric circulation?

[Aluminium]

May 8-13.

2020.

[Jim Hunt]

A clear(ish) view of the Chukchi Sea this morning:

https://GreatWhiteCon.info/2021/05/facts-about-the-arctic-in-may-2021/#May-14

[johnm33]

I looked at this Hycom sss mainly to see the discharge, if any, from Jkbshvn, but noticed that the odd spot around 110E seems to indicate almost fresh water in it's center. Apr.21-May.20

[gerontocrat]

I am a numbers man. BUT....

If you look at JAXA sea ice extent losses you see losses have stalled in the last 2 days.
If you look at Aluminium's gif (3 posts above) you see a huge area of the icepack in the Atlantic Front appears to have collapsed, pretty much all the way to the pole.

The NIC colours image adds even more drama.