Home brew AMSR2 extent & area calculation

[jdallen]

This is the eastern Kara and approaches to the Barents sea.   I presume the ice hidden in the western Kara is disintegrating rapidly as well.

[Wipneus]

In that case Beaufort is today's image. I still think it can go either way.

[Wipneus]

This is the eastern Kara and approaches to the Barents sea.   I presume the ice hidden in the western Kara is disintegrating rapidly as well.

http://earth.nullschool.net/ shows wind from the east over Kara. The ice in the west shows some  sign of compression.

[Wipneus]

Update 20140702.

Extent: -81k4 (-440k vs 2013, -30k vs 2012)
Area: -40k3 (-214k vs 2013, +59k vs 2012)

Most of the melting is in the Arctic Basin, extent and area are near 2012 levels. Regions that contribute most are Kara, Barents and Beaufort Seas.

 
You will find the updated graphs in the top post

The details (in 1000 km²):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -4.7                     1.8                    -8.8
               Kara Sea             Barents Sea           Greenland Sea
                  -16.3                   -14.6                    -0.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -16.3                     0.0                    -5.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -2.0                   -11.1                    -4.8
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.9                     0.6                   -81.4

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -0.3                    12.4                    -6.7
               Kara Sea             Barents Sea           Greenland Sea
                  -11.0                   -13.8                    18.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -10.8                     0.0                   -11.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -3.0                    -9.8                    -6.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.5                     0.4                   -40.3

[Wipneus]

Kara has enough ice that is already broken badly for sustained melting in the coming July.

[ChrisReynolds]

Wipneus,

For your regional data do you use the CT Area regions?

I wonder because there are large differences between your extent data and MASIE - MASIE regions are (IIRC) quite different from CT Area.

I ask because I'm going to be using your CSV data in my latest blog post.

[Wipneus]

Wipneus,

For your regional data do you use the CT Area regions?

I wonder because there are large differences between your extent data and MASIE - MASIE regions are (IIRC) quite different from CT Area.

I ask because I'm going to be using your CSV data in my latest blog post.

I am using a mask derived from the one from CT area. The (minimal) changes are there for some obvious mistakes (marking sea ice as lake for instance), and to make it possible to use the same mask not just for 25k, but also on a 3.125km grid and everything between those.

MASIE is quite different. The CAB is much smaller, 3.25 Mm² vs 4.45 Mm², for instance.

I can see the logic in MASIE's regions, but it not discussed as much as the CT regions. Calculating the regional CT-area data (for which there is no numerical data) was one of the goals anyway.

I plan to discuss this and other design decisions sometime later, probably in the freezing season. There are an enormous amount of domestic things that require my attention in these months.

[ChrisReynolds]

Thanks Wipneus.

[Bruce]

There are an enormous amount of domestic things that require my attention in these months.

Just wanted to add my voice to the others thanking you for your work here. What you're doing is important and very much appreciated. I'm sure it takes quite a bit of effort to stay on top of everything, and the results are really impressive. Thanks.

[ktonine]

Let me add to the chorus.  I read your updates religiously (Church of Latter Day Armchair Polar Explorers), but usually feel no need to comment.  Thanks for all the time and effort you've put into this.

kto

[Wipneus]

Update 20140703.

Extent: -28k2 (-335k vs 2013, +38k vs 2012)
Area: -18k4 (-20k vs 2013, +173k vs 2012)

Surprisingly slow declines today.  This slowness can be seen in the regions as well, no big declines or upticks. Beaufort and Kara had the biggest declines in area, but Kara had an equal sized uptick in area.

You will find the updated graphs in the top post

The details (in 1000 km²):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -1.2                     8.1                    -1.2
               Kara Sea             Barents Sea           Greenland Sea
                  -12.3                    -2.1                     1.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -0.2                    -0.1                     0.6
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    1.7                   -14.2                    -6.9
             Bering Sea          Sea of Okhotsk            Total Extent
                   -1.6                     0.1                   -28.2

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                    0.7                    11.2                    -2.5
               Kara Sea             Barents Sea           Greenland Sea
                   10.7                     0.1                    -5.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -0.6                     0.0                   -14.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -2.3                    -6.8                    -9.0
             Bering Sea          Sea of Okhotsk              Total Area
                   -0.9                     0.2                   -18.4

[Wipneus]

It is a bit looking for activity in the Arctic change map. Kara was highlighted yesterday, so it is the Beaufort/CAA open water. The decline of the icepack has been steady during the last weeks, but at this rate it will still take a month before the Beaufort melts out.

[jdallen]

It is a bit looking for activity in the Arctic change map. Kara was highlighted yesterday, so it is the Beaufort/CAA open water. The decline of the icepack has been steady during the last weeks, but at this rate it will still take a month before the Beaufort melts out.

A month is all it needs.

[Wipneus]

Transport through the Fram is taking up a little, not so much in the strait that is not named Olga where it is reversed.

[Wipneus]

Update 20140704.

Extent: -19k4 (-150k vs 2013, +123k vs 2012)
Area: -30k1 (+75k vs 2013, +313k vs 2012)

Second relatively slow day  brings area again above the 2013 same day level. This is caused in part by a rebound in the Hudson Bay. The only region that stands out with a big decline is Kara. Extent in Kara is still significantly above 2013 and this decline is not bringing it any closer.

CAB area increased again, the ice compactness  (area/extent) in the CAB is now 98.6% in 2013 it was 95.1% and in 2012 97.0%. Note: these numbers can be quite different for different sea ice concentration data, I will calculate the NSIDC numbers when they become available later today.
 
You will find the updated graphs in the top post

The details (in 1000 km²):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                    0.9                    -0.4                    -2.7
               Kara Sea             Barents Sea           Greenland Sea
                  -23.7                     3.9                    -8.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -2.4                     0.0                    27.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -10.4                    -1.1                    -2.2
             Bering Sea          Sea of Okhotsk            Total Extent
                   -0.5                    -0.1                   -19.4

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   14.8                    -0.7                    -6.3
               Kara Sea             Barents Sea           Greenland Sea
                  -25.4                     5.8                   -13.3
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    0.9                     0.0                    24.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -11.0                   -12.6                    -5.6
             Bering Sea          Sea of Okhotsk              Total Area
                   -1.2                    -0.1                   -30.1

[Wipneus]

For the middle of the melt season there is very little happening in the Arctic. No interesting polynya in the CAB anywhere now like in 2013, little activity in other regions. Kara was already highlighted yesterday.

So I have to go small with the Nares Strait, the arch did break, lots of ice broke loose and is speeding south but the northern part of the strait is still holding.

[TerryM]

Thanks so much Wipneus, I estimate that the plug added ~ a week to the blockage time when it fell in place. Without it I think that Nares would be open now so I'll be awaiting it's failure.
Terry

[Bruce]

Wipneus, I like the animations you make of the concentration data. If you're looking to things to highlight, I have a suggestion: One way that I can tell when melt will reach a certain near shore area is by watching how the melt proceeds in the lakes, ponds, and rivers adjacent to it. It would be interesting to see one of your animations for maybe the past two weeks of the region south of the ESS (which we haven't been able to see for a while because of the clouds), or the area south of the CAA -- either the region around the Great Bear Lake or farther to the east.

[Wipneus]

Update 20140705.

Extent: -72k3 (-114k vs 2013, +245k vs 2012)
Area: -95k0 (-24k vs 2013, +429k vs 2012)

Hudson Bay, where a lot of low concentration ice is still lingering, drives the numbers down (in absolute sense)  today. Yesterday it was the reverse. In extent the only substantial change is in Laptev which went down -26k. In area, there where declines  in the Laptev,  Kara, ESS and CAB, the Canadian Archipelago had a big area uptick.

You will find the updated graphs in the top post

The details (in 1000 km²):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -2.4                    -6.6                   -26.0
               Kara Sea             Barents Sea           Greenland Sea
                   -3.9                     0.2                    -7.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -1.8                     0.4                   -25.6
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    0.6                     4.2                    -4.1
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.2                     0.0                   -72.3

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                  -16.5                   -18.4                   -26.1
               Kara Sea             Barents Sea           Greenland Sea
                  -25.6                    -4.5                     5.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    3.5                     0.2                   -22.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   20.7                    -2.0                    -9.3
             Bering Sea          Sea of Okhotsk              Total Area
                    0.6                     0.0                   -95.0

[Wipneus]

If you're looking to things to highlight, I have a suggestion: One way that I can tell when melt will reach a certain near shore area is by watching how the melt proceeds in the lakes, ponds, and rivers adjacent to it. It would be interesting to see one of your animations for maybe the past two weeks of the region south of the ESS (which we haven't been able to see for a while because of the clouds), or the area south of the CAA -- either the region around the Great Bear Lake or farther to the east.

Bruce, the problem here is that lakes, ponds and rivers have been masked out in the Uni Hamburg sea ice concentration product. It even means not data for the big lakes, where almost all products have data. The 3.125 km resolution would make it even more interesting.


Any way here is an animation of ESS and Laptev. The ice in the East Siberian Sea is not moving much, I guess a totally change of winds is needed here to get that going. In Laptev the ice is rapidly disappearing, some funny pit of resistant  (i)landfast ice can be seen in the middle.

click the picture for the animation to start.

[Wipneus]

Yet another illustration how the ice in the Hudson Bay makes big impacts in the daily changes summary.

[Wipneus]

I was thinking, it would be quite useful for our understanding if I could add a map of the winds to the regional maps. Like what Sonia did here

To automate this I would need a tool that could make a graphic image from a website like http://earth.nullschool.net/#2014/07/05/1200Z/wind/surface/level/stereographic=-45.00,90.00,2683.

I tried cutycapt but that does not seem to render the earth and wind images.
Does anyone know such a tool that works with earth.nullschool.net ? Is there another simple means to do what I want ?

[SteveMDFP]

I was thinking, it would be quite useful for our understanding if I could add a map of the winds to the regional maps. Like what Sonia did here

To automate this I would need a tool that could make a graphic image from a website like http://earth.nullschool.net/#2014/07/05/1200Z/wind/surface/level/stereographic=-45.00,90.00,2683.

I tried cutycapt but that does not seem to render the earth and wind images.
Does anyone know such a tool that works with earth.nullschool.net ? Is there another simple means to do what I want ?

Experimenting some, I found that the nullschool images can be screen captured with the plain old "print screen" key, which copies the screen image to the clipboard (in Windows XP in my antiquated case).  There are a number of screen capture automation programs out there (e.g., http://sourceforge.net/projects/autoscreen/ ).
One of these screen capture utilities may be what you need to prepare the kind of images you describe.
I hope this might aid you in the extraordinary work you do for us here.

[Jim Hunt]

Does anyone know such a tool that works with earth.nullschool.net ? Is there another simple means to do what I want?

I use Shutter for manual screen captures - http://shutter-project.org/

It can be used from the command line, and has the ability to capture a screen shot from a URL. However it doesn't seem to wait long enough for nullschool.net to load before clicking its shutter. Manual versus automatic:

[Bruce]

Wipneus -- Thanks for the explanation, that makes sense. I'll look around and see if I can find a data set that will let us do this. It would be interesting to watch the melt and subsequent freeze up including the lakes and rivers.

I use Shutter for manual screen captures - http://shutter-project.org/

It can be used from the command line, and has the ability to capture a screen shot from a URL. However it doesn't seem to wait long enough for nullschool.net to load before clicking its shutter. Manual versus automatic:

It's open source, so someone with time and ambition should be able to find a spot in the program to put a rendering delay and a "--delay" option on the command line. Or you could try asking the authors to include a delay in the next release. Maybe the group of us could even scrounge up some cash for a donation that would grease the wheels a bit. If another solution isn't found, that is.

[Wipneus]

Update 20140706.

Extent: -105k2 (-185k vs 2013, +251k vs 2012)
Area: -160k1 (-136k vs 2013, +376k vs 2012)

Big declines in Laptev and Kara cause big totals. In the ESS, Chukchi and CAB area declines cause the total area to go down faster than extent.
 
You will find the updated graphs in the top post

The details (in 1000 km²):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -8.5                    -4.9                   -34.3
               Kara Sea             Barents Sea           Greenland Sea
                  -15.9                     2.8                    -5.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -6.5                    -0.3                   -28.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -1.6                     2.0                    -2.8
             Bering Sea          Sea of Okhotsk            Total Extent
                   -1.7                     0.0                  -105.2

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                  -19.5                   -16.9                   -34.2
               Kara Sea             Barents Sea           Greenland Sea
                  -35.7                     2.9                   -11.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -4.9                    -0.2                   -20.6
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -6.0                     3.1                   -14.9
             Bering Sea          Sea of Okhotsk              Total Area
                   -1.5                     0.0                  -160.1

[jdallen]

Update 20140706.

Extent: -105k2 (-185k vs 2013, +251k vs 2012)
Area: -160k1 (-136k vs 2013, +376k vs 2012)

Big declines in Laptev and Kara cause big totals. In the ESS, Chukchi and CAB area declines cause the total area to go down faster than extent.

If this continues, it will confirm the expectation I had of these areas and the Beaufort picking up where the Hudson and Baffin left off in recent high area and extent declines.

[Wipneus]

The biggest decliners combined provide images of the day. The nullschool image is just a cropped screen capture.

[werther]

Thanks, Wipneus,

I elaborated a bit on the actual quality of the ice in this part of your excellent graph/map (melt season-thread):



Your nullschool screenshot illustrates one of the reasons why the ice is rapidly deteriorating in this region.

[forkyfork]

what accounts for the big differences between the numbers here and CT area numbers? if it's been explained earlier in this thread i apologize

[Jim Hunt]

Does anyone know such a tool that works with earth.nullschool.net ? Is there another simple means to do what I want ?

I discovered that shutter relies on gnome-web-photo for capturing a URI, and that recent versions of gnome-web-photo have a --delay option. The only problem then is that you end up with a very small picture of planet Earth!

I've tweaked the gnome-web-photo source to get around that problem, but I'm not sure if the result would be suitable for your purposes. I haven't tried as yet, but I doubt that it would work without an X display of some sort for example.

https://git.gnome.org/browse/gnome-web-photo/

[Rubikscube]

If anyone was wondering how 2014 compared to other years on the 6^th of July, then you might enjoy these comparison maps.

[Wipneus]

Update 20140707.

Extent: -78k0 (-167k vs 2013, +234k vs 2012)
Area: -113k5 (-161k vs 2013, +315k vs 2012)

Extent decline is not enough to stay with 2012, we are closer to 2013 now. Distances are small though, strong melting or a stagnation in the coming weeks can make all the difference. Of the -78k decline in extent about -30k can be attributed to the regions outside the arctic basin. Within, it is Kara that takes the big share. Area decline is stronger, caused by lower ice concentration in the CAB, Beaufort and ESS.
 
You will find the updated graphs in the top post

The details (in 1000 km²):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -7.9                    -3.3                    -9.4
               Kara Sea             Barents Sea           Greenland Sea
                  -20.9                    -0.6                   -18.3
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -8.6                     0.0                    -3.4
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    4.2                    -4.9                    -4.1
             Bering Sea          Sea of Okhotsk            Total Extent
                   -0.7                    -0.1                   -78.0

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                  -23.4                   -11.3                    -9.3
               Kara Sea             Barents Sea           Greenland Sea
                  -16.9                    -0.2                   -18.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -7.8                     0.0                    -2.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -6.7                   -16.2                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                   -1.3                     0.0                  -113.5

[Wipneus]

Region of the day is Beaufort. After I showed is last, this region has steadily declined in concentration without spectacular jumps. With favorable weather ( as always) the region looks like it could make some bigger strides now.

[Wipneus]

Does anyone know such a tool that works with earth.nullschool.net ? Is there another simple means to do what I want ?

I discovered that shutter relies on gnome-web-photo for capturing a URI, and that recent versions of gnome-web-photo have a --delay option. The only problem then is that you end up with a very small picture of planet Earth!

I've tweaked the gnome-web-photo source to get around that problem, but I'm not sure if the result would be suitable for your purposes. I haven't tried as yet, but I doubt that it would work without an X display of some sort for example.

https://git.gnome.org/browse/gnome-web-photo/

There is a frame buffer device of course. It needs a bit too much experimenting for which I have not the time.

I have settled for now using SimpleWebCapture plugin in Firefox, a script takes care of proper scaling and alignment with the sea ice concentration images. The whole process just adds a few clicks to the daily routine. You can see the result tomorrow.

Thank you guys for the ideas and suggestions.

[Wipneus]

Update 20140708.

Extent: -103k0 (-127k vs 2013, +218k vs 2012)
Area: -94k7 (-109k vs 2013, +311k vs 2012)

Many regions contribute to an extent century with Kara declining most. Area decline is a bit smaller with Kara and the CAB as exceptions.

You will find the updated graphs in the top post

The details (in 1000 km²):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                  -10.1                   -14.4                    -8.8
               Kara Sea             Barents Sea           Greenland Sea
                  -20.9                    -0.4                   -13.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -0.8                     0.0                    -6.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -6.8                   -10.0                    -7.9
             Bering Sea          Sea of Okhotsk            Total Extent
                   -3.2                     0.0                  -103.0

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                  -27.5                   -10.9                    -4.8
               Kara Sea             Barents Sea           Greenland Sea
                  -24.0                    -1.7                     3.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -3.1                     0.0                    -1.4
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    1.6                   -15.7                    -8.9
             Bering Sea          Sea of Okhotsk              Total Area
                   -1.9                    -0.2                   -94.7

[Michael Hauber]

Early July 2010 and mid July 2011 marked a transition to a low pressure dominated SLP pattern, and also marked a significant slowdown of these melt seasons.  Current model runs now extend to middle July, and although there is some low pressure activity, there is no sign yet of a low pressure dominated pattern setting in.  It will be interesting to see if 2014 will overtake 2010 and 2011 later this month, we are currently only a couple days behind by IJIS extent, but further behind in area.

[Wipneus]

Today region is the Atlantic section of the CAB. A peculiar patch of low concentration (~50%) ice has appeared quite near the pole. I am not sure what it means, it has existed a couple of days so there is probably something there but on the other hand Jaxa and NSIDC maps don't show much.
Winds are such that Fram transport has stopped, ice now exits on both sides of Franz Josef Land.

[jdallen]

Today region is the Atlantic section of the CAB. A peculiar patch of low concentration (~50%) ice has appeared quite near the pole.

Last year, I recall us speculating over whether some of the swath of low concentration was tied to upwelling from warm currents which enter from both sides of Svalbard at lower depth.  Why they should surface, or the heat might appear in the middle of the pack, I'm not sure, but  tracking the traditional routes of the currents, that's one possible explanation, especially in the face of relatively little wind and cloudiness.

OTOH, It may be something entirely new.

[BornFromTheVoid]

There's been high pressure over the Barents sea recently, which has ridged toward the N. Pole and pulled some mild surface air with it. It may have cause some melt ponding, as most of the ice/snow above 80N has been pretty well sheltered so far this summer.

[Peter Ellis]

Whatever it is on the microwave images, it's not real ice loss.  The area's nice and clear on the most recent MODIS pictures, and is still ~100% concentration and bright white, so not even a lot of melt ponding yet.

http://1.usa.gov/1xQQSh2
http://1.usa.gov/1zoJbQU

[Wipneus]

This is exactly the same region, same date,  Terra MODIS 2km (visible, contrast enhanced to bring out the subtle shades of blue and green).
The patch is half under those clouds and half in the clear area.
I am not convinced that there is anything there.

 

[SteveMDFP]

Does anyone know such a tool that works with earth.nullschool.net ? Is there another simple means to do what I want ?
....
I have settled for now using SimpleWebCapture plugin in Firefox, a script takes care of proper scaling and alignment with the sea ice concentration images. The whole process just adds a few clicks to the daily routine. You can see the result tomorrow.

Thank you guys for the ideas and suggestions.

I'm glad you found a workable solution.  Seeing the wind fields adds quite a lot to understanding what's going on in the various regions.  Thans so much for your work here.

[Frivolousz21]

Higher frequency channels like SSMI 85 ghz, ssmis 91 ghz, and amsr2 89 ghz are prone to showing low concentration when there is thin ice present.

It's likely been to cold or to cloudy for it to show up so far.

SSMIS really lays it out there. 

It's not on Jaxa because Jaxa uses the lower frequency channels but it's on channel 89ghz.

http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e


JdAllen was half way right it's definitely from up-welling. 

It's even more clear on SSMIS channel 91ghz.

It's origin is probably the Laptev bite.

[Bruce]

It's under cloud cover today, but it was there yesterday and there was no sign of it on MODIS.

[TerryM]

Oden should be entering the ice between Franz Josef & Vize today. They may have interesting observations.
http://www.swerus-c3.geo.su.se/index.php/swerus-media


Terry

[Wipneus]

Update 20140709.

Extent: -127k2 (-127k vs 2013, +334k vs 2012)
Area: -121k1 (-104k vs 2013, +366k vs 2012)

The strong declines today are comparable with same date 2013 but a bit less than 2012.  Kara, again, takes the biggest share with Laptev, Chukchi and Beaufort close behind.

 
You will find the updated graphs in the top post

The details (in 1000 km²):


Extent:
           Arctic Basin       East Siberian Sea              Laptev Sea
                  -13.2                   -11.6                   -19.5
               Kara Sea             Barents Sea           Greenland Sea
                  -24.3                    -1.9                     1.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -15.0                    -0.1                    -4.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -3.9                   -16.2                   -17.6
             Bering Sea          Sea of Okhotsk            Total Extent
                   -1.3                     0.4                  -127.2

Area:
           Arctic Basin       East Siberian Sea              Laptev Sea
                   -3.8                    -6.7                    -9.6
               Kara Sea             Barents Sea           Greenland Sea
                  -19.8                    -0.7                   -20.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -14.3                    -0.1                    -1.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    1.9                   -25.4                   -20.7
             Bering Sea          Sea of Okhotsk              Total Area
                   -0.9                     0.5                  -121.1

[Wipneus]

The Chukchi Sea has been declining in a slow but steady pace, that may be accelerating. As the images show the winds are parallel to the edge of the ice pack, so the Coriolis forces may compress the ice somewhat but it probably also brings melting power (=heat) here.

[Wipneus]

A sequence of the CAB may show some context to the blotch discussed above. Watching how the ice is moving, it also shows that what I called the Beaufort Gyre could be regarded as something a whole lot bigger, an Arctic Gyre.

(click for a 2MB animation)

[Shared Humanity]

That Arctic gyre seems to be having the effect of keeping the ice in the basin. Little export from Fram...some movement toward Franz Josef.