Support the Arctic Sea Ice Forum and Blog

Author Topic: Home brew AMSR2 extent & area calculation  (Read 1090402 times)

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1350 on: October 29, 2014, 07:58:47 AM »
Baffin Bay starts to ice over from the north, from this animation it seems to be a mix of transport and in-situ meltfreeze.
« Last Edit: November 02, 2014, 09:30:20 AM by Wipneus »

Tor Bejnar

  • ASIF Upper Class
  • Posts: 1497
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1351 on: October 31, 2014, 06:37:40 PM »
I presume you mean "in-situ freeze"
 ::)
Arctic ice is healthy for children and other living things.

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1352 on: November 02, 2014, 09:38:14 AM »
Thanks Tor. Yes, of course "freeze".

Meanwhile, the Fram export seems now to be starting after a long pauze. The West Spitsbergen Current contrasts clearly with the south going ice. The Barents ice cover has made up the temporary decline and is now quite ahead of recent years (but not with longer time normal).

(click for an animation)

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1353 on: November 05, 2014, 08:47:06 AM »
Update 20141104.
Changes from 20141028.

Extent: +631.2 (+46k vs 2013, +1044k vs 2012)
Area: +688.1 (-16k vs 2013, +959k vs 2012)

Reporting the changes in the last week. Freezing continues with near century daily increases without any sign of a "pause". Now the Central Basin, Laptev Sea and the Canadian Archipelago have nearly completely frozen the extent increase continues in the Barents,  Beaufort and the (eastern part) of the East Siberian Seas. There is some decline in the west of Kara Sea and very little freezing in the Chukchi Sea.
 
You will find the updated graphs in the top post

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   31.0                   112.5                    44.4
               Kara Sea             Barents Sea           Greenland Sea
                  -24.0                   125.3                    63.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   36.1                     0.7                    25.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -10.8                   167.6                    58.6
             Bering Sea          Sea of Okhotsk            Total Extent
                    3.5                    -2.0                   631.2

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   54.3                   137.5                    89.0
               Kara Sea             Barents Sea           Greenland Sea
                  -25.7                   112.8                    62.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   41.0                     0.4                    19.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -18.7                   166.0                    48.6
             Bering Sea          Sea of Okhotsk              Total Area
                    2.1                    -1.5                   688.1


Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1354 on: November 07, 2014, 09:37:52 AM »
The east of the Eastern Siberian Sea is remarkably stubborn as regard to refreezing.

jdallen

  • ASIF Upper Class
  • Posts: 2434
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1355 on: November 07, 2014, 06:55:14 PM »
The east of the Eastern Siberian Sea is remarkably stubborn as regard to refreezing.

I suspect the ESS, Chukchi, and to a lesser extent, the Beaufort refreezes are being slowed by the stupendous inputs if energy they are receiving from storms, which appears to be displacing colder air.  It looks like North Am. will experience a major breakout next week because of Nuri.  There is flow on the Atlantic side as well, which might account for the retreat in the Kara. The Hudson and Baffin seem to have lower than usual coverage, and it seems there was some retreat in the CAA as well.

Go figure ;)

Meanwhile temperatures in central and western Siberia have been low, and snowfall high.  Lots of heat flying around trying ti find equilibrium, and not succeeding, seems.
This space for Rent.

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1356 on: November 12, 2014, 07:57:53 AM »
In case anyone is waiting for updates from the data, graphics or pasted animations: there have been no updates from Uni Hamburg after that from the 9th of November.


Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1357 on: November 15, 2014, 08:24:07 AM »
Update 20141111.
Changes from 20141104.

Extent: +311.2 (+155k vs 2013, +856k vs 2012)
Area: +270.8 (+144k vs 2013, +903k vs 2012)

Some data came in, enough to finish the report I intended to make.

Reporting the changes in the week from November 4-11.
Refreezing has slowed down considerably, with daily changes in total extent/area of around 40k. Most of the growth has now moved to the Baffin Bay and all other regions on the Atlantic (from Hudson to Kara) side. The Pacific side (Beaufort, Chukchi and ESS) is very slow, even with some declines.
 
You will find the updated graphs in the top post

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                    4.0                    -1.7                     9.2
               Kara Sea             Barents Sea           Greenland Sea
                   41.7                    43.6                    44.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   96.7                    -0.6                    32.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   41.6                   -14.1                    13.5
             Bering Sea          Sea of Okhotsk            Total Extent
                    1.5                    -1.5                   311.2

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                    5.9                    -3.4                    29.8
               Kara Sea             Barents Sea           Greenland Sea
                   53.7                    42.8                    37.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   76.2                    -0.3                     4.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   44.7                   -30.8                     9.3
             Bering Sea          Sea of Okhotsk              Total Area
                    1.5                    -0.8                   270.8


Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1358 on: November 15, 2014, 08:27:17 AM »
An animation of the Greenland Sea shows the Fram export is finally(?) picking up.

(needs a click to animate)

ChrisReynolds

  • ASIF Upper Class
  • Posts: 1714
    • View Profile
    • Dosbat
Re: Home brew AMSR2 extent & area calculation
« Reply #1359 on: November 16, 2014, 07:23:14 PM »
Wipneus,

The slowing of extent increase seems to me to be common in early November a geographic constraints slow the rate of increase, mainly Chuckchi/Bering Straits.

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1360 on: November 19, 2014, 04:00:40 PM »
Wipneus,

The slowing of extent increase seems to me to be common in early November a geographic constraints slow the rate of increase, mainly Chuckchi/Bering Straits.

It is "normal" for the rates to slow down at this time of year, often even show some day-to-day decreases at some moments. Geographical constraints of course, but also lots of thin and/or low concentration ice that may dip under the 15% under forces of winds and currents.

This week the Chukchi and Bering regions contribute nothing to the refreeze, there is even some small decline in both. See the next post.

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1361 on: November 19, 2014, 04:10:54 PM »
Update 20141117.
Changes from 20141110.

Extent: +533.9 (+344k vs 2013, +870k vs 2012)
Area: +614.8 (+373k vs 2013, +900k vs 2012)

Reporting the changes in the week from November 11-17.
This week the refreeze has sped up again, with daily growth of about 80k. As last week the regions to the Atlantic side contribute most with the Hudson region first with the Barents Sea as second.
 
You will find the updated graphs in the top post

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   15.3                    76.2                    -1.7
               Kara Sea             Barents Sea           Greenland Sea
                   74.5                    92.3                    44.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   62.2                    -0.2                   120.4
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   12.5                    43.5                    -5.5
             Bering Sea          Sea of Okhotsk            Total Extent
                   -2.0                     2.3                   533.9

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   14.4                   100.5                    -8.2
               Kara Sea             Barents Sea           Greenland Sea
                   66.1                    82.9                    46.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   77.9                    -0.2                   112.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   31.9                    80.9                    10.1
             Bering Sea          Sea of Okhotsk              Total Area
                   -1.4                     1.4                   614.8


Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1362 on: November 24, 2014, 08:17:41 AM »
Sea ice is still passing through the Nares Strait.

viddaloo

  • ASIF Upper Class
  • Posts: 1302
  • Hardanger Sometimes
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1363 on: November 24, 2014, 09:16:55 AM »
Interesting, Wipneus.

Here's an article from NASA about the 2007 winter transport through Nares.
[]

jdallen

  • ASIF Upper Class
  • Posts: 2434
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1364 on: November 24, 2014, 09:45:45 AM »
Interesting, Wipneus.

Here's an article from NASA about the 2007 winter transport through Nares.

Good article.

I wonder if the fact it is still open is attributable to the mechanical changes we've seen take place in the pack over the last three years.  That is, the shattering of the larger expanses of shoreline-anchored ice, and general breakdown of flows into relatively small elements which lack structural coherence.

It may just be serendipitous, and the flow has been just right, and the ice floes just right such that nothing has stuck yet.
This space for Rent.

Peter Ellis

  • ASIF Middle Class
  • Posts: 549
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1365 on: November 24, 2014, 07:59:18 PM »
According to the Canadian Ice Service, the Nares strait is typically open (i.e. mobile ice) until about February, which then consolidates until breakup around the end of July
http://www.ice-glaces.ec.gc.ca/app/WsvPageDsp.cfm?Lang=eng&lnid=50&ScndLvl=no&ID=11924&PrintFmt=True

This paper from 2010 backs up that timing...
http://rkwok.jpl.nasa.gov/publications/Kwok.2010.GRL.pdf

... as does their previous paper from 2005
http://rkwok.jpl.nasa.gov/publications/Kwok.2005e.GRL.pdf


Bottom line is that there isn't unusual going on there right now - in fact, if export had stopped, it would be among the earliest on record. We expect to see continued export through Nares for another couple of months yet.

jdallen

  • ASIF Upper Class
  • Posts: 2434
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1366 on: November 24, 2014, 10:54:07 PM »
According to the Canadian Ice Service, the Nares strait is typically open (i.e. mobile ice) until about February, which then consolidates until breakup around the end of July
http://www.ice-glaces.ec.gc.ca/app/WsvPageDsp.cfm?Lang=eng&lnid=50&ScndLvl=no&ID=11924&PrintFmt=True

This paper from 2010 backs up that timing...
http://rkwok.jpl.nasa.gov/publications/Kwok.2010.GRL.pdf

... as does their previous paper from 2005
http://rkwok.jpl.nasa.gov/publications/Kwok.2005e.GRL.pdf


Bottom line is that there isn't unusual going on there right now - in fact, if export had stopped, it would be among the earliest on record. We expect to see continued export through Nares for another couple of months yet.

Good news then, nothing out of the ordinary.
This space for Rent.

Sonia

  • ASIF Lurker
  • Posts: 57
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1367 on: November 25, 2014, 08:11:47 PM »
The Nares is one of my favorite places to watch.  Thanks for that animation Wipneus.  I like the images on the DMI site http://ocean.dmi.dk/arctic/lincoln.uk.php (which is back up today after being down for a few days over the weekend.)  And I've gotten a lot out of the comments in the Nares Strait thread here  http://forum.arctic-sea-ice.net/index.php/topic,176.0.html]here [url]http://forum.arctic-sea-ice.net/index.php/topic,176.0.html[/url].  On the DMI site you can access last year's images for comparison and watch last year's "stopper" wedge in the Robeson channel around the first of the year.

Laurent

  • ASIF Governor
  • Posts: 2525
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1368 on: November 25, 2014, 09:40:13 PM »
This year I see a trail of thick ice brought away from the Naires strait and a big anomaly in the Bering/Chukchi.

crandles

  • ASIF Upper Class
  • Posts: 1776
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1369 on: November 25, 2014, 11:24:08 PM »
This year I see a trail of thick ice brought away from the Naires strait and a big anomaly in the Bering/Chukchi.

That looks like a mis-match of images to me. Your first two look like ARC images, the proper comparison being as below:







Not sure if there are comparison images available for your 2014 image.

Jim Hunt

  • ASIF Governor
  • Posts: 3303
    • View Profile
    • The Arctic sea ice Great White Con
Re: Home brew AMSR2 extent & area calculation
« Reply #1370 on: November 26, 2014, 11:29:17 AM »
Not sure if there are comparison images available for your 2014 image.

The (not yet operational!) GOFS archives only go back to the beginning of this year:

http://www7320.nrlssc.navy.mil/GLBhycomcice1-12/navo/arc_list_arcticictn.html
Reality is merely an illusion, albeit a very persistent one - Albert Einstein

Laurent

  • ASIF Governor
  • Posts: 2525
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1371 on: November 26, 2014, 03:54:04 PM »
Sorry, I started with 2014 but seeing there wasn't any archive I switched to ARC but did forget to uptade the 2014.
That doesn't change what I have written, A smal export of thick ice in the barentsz and a very impressive lack of ice in the Chukchi.
« Last Edit: November 26, 2014, 04:12:20 PM by Laurent »

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1372 on: November 27, 2014, 09:09:39 AM »
Update 20141125.
Changes from 20141118.

Extent: +363.7 (+48k vs 2013, +171k vs 2012)
Area: +334.8 (+22k vs 2013, +280k vs 2012)

Reporting the changes in the week from November 18-25.
This week the increase was rather slow, about 50k/day, resulting in extent and area at about 2013 levels. Also the distance from 2012 has been greatly reduced: about +200k from +900k a week ago.
Most of the freeze this week was in the Hudson region: +180k, other regions increasing much slower. Chukchi extent did increase by +44k but is still very low compared with recent years.


You will find the updated graphs in the top post

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -28.4                    39.5                     2.9
               Kara Sea             Barents Sea           Greenland Sea
                   21.9                    -1.8                    20.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   30.5                    -0.8                   181.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   19.4                     5.9                    44.7
             Bering Sea          Sea of Okhotsk            Total Extent
                   23.7                     3.2                   363.7

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -29.8                    39.5                    13.7
               Kara Sea             Barents Sea           Greenland Sea
                    6.3                   -17.8                     9.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   22.8                    -0.8                   173.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   43.1                    22.8                    37.8
             Bering Sea          Sea of Okhotsk              Total Area
                   11.7                     1.7                   334.8


Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1373 on: November 27, 2014, 09:15:23 AM »
Animation of the Greenland Sea shows that the transport through the Fram Strait has stalled again. The responsible southerlies also keep the ice in the Barents Sea in check.

(needs a click to animate)

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1374 on: November 29, 2014, 09:06:06 AM »
Meanwhile in the Beaufort the Gyre has started as this 10 day animation shows.

(needs a click to animate)

jdallen

  • ASIF Upper Class
  • Posts: 2434
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1375 on: November 30, 2014, 09:11:40 AM »
Amazing!

I do  believe your animation is showing some ice *melting* when it gets into the Chukchi.  Not a lot, but even so, pretty amazing.
This space for Rent.

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1376 on: December 04, 2014, 08:02:44 AM »
Update 20141203.
Changes from 20141126.

Extent: +632.0 (+61k vs 2013, +599k vs 2012)
Area: +632.0 (+54k vs 2013, +552k vs 2012)

Reporting the changes in the week from November 26-December 3.
This week the ice increased at a rate of about  90k/day nearly double compared with last week. As a result extent and area stayed near 2013 levels but gained compared with 2012.
This week the atmospheric pressure was in a sort of anti-dipole configuration: low pressure over the Canadian Islands and High pressure over Laptev. As a result ice cover declined over the Barents and Greenland Sea and gained on the Pacific side, East Siberian Sea and Chukchi.
The biggest changes however are in the Hudson and Baffin Bay regions, looking at the regional graphs Hudson is a few days early for your average refreeze season.
You will find the updated graphs in the top post

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   -6.5                    17.1                     0.0
               Kara Sea             Barents Sea           Greenland Sea
                   35.5                    15.7                   -41.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  114.8                    -0.3                   410.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    6.6                     7.6                    54.7
             Bering Sea          Sea of Okhotsk            Total Extent
                    2.7                    14.7                   632.0

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -58.8                    13.7                     0.2
               Kara Sea             Barents Sea           Greenland Sea
                   59.6                    13.8                   -32.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  116.6                    -0.1                   386.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   18.0                    32.4                    61.6
             Bering Sea          Sea of Okhotsk              Total Area
                   10.0                    11.1                   632.0


Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1377 on: December 04, 2014, 08:09:32 AM »
The crack north of the Canadian Archipelago is back again, now it is extending all the way across the Fram Strait.

(click to animate)

jdallen

  • ASIF Upper Class
  • Posts: 2434
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1378 on: December 04, 2014, 09:04:50 AM »
The crack north of the Canadian Archipelago is back again, now it is extending all the way across the Fram Strait.

(click to animate)
That, is a disturbing image.  Thank you, Wipneus.
This space for Rent.

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1379 on: December 11, 2014, 08:38:52 AM »
Update 20141210.
Changes from 20141203.

Extent: +468.7 (+70k vs 2013, +330k vs 2012)
Area: +460.0 (+10k vs 2013, +275k vs 2012)

Commenting the changes in the week from December 3-10.
Refreezing continues at a rate of about +65k/day. This keeps total ice extent/area in 2014 at about the same levels as in 2013. The gap with 2012 has been nearly halved (compared with last week)  to about +300k.
In the Arctic Basin winds continues to enhance growth in Chukchi and a decline in the Barents region. The decline in the Greenland Sea did reverse however since the center of low pressure did move over the Svalbard islands. The Hudson is now nearly 100% covered with ice, normally a reason for a sharp slow down in total sea ice growth.

You will find the updated graphs in the top post

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   -8.7                    22.5                    -1.6
               Kara Sea             Barents Sea           Greenland Sea
                   -5.3                   -52.5                    46.3
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   99.8                    -0.2                   214.6
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -0.3                     0.0                   105.5
             Bering Sea          Sea of Okhotsk            Total Extent
                   33.6                    14.9                   468.7

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   35.2                    34.6                    -6.3
               Kara Sea             Barents Sea           Greenland Sea
                   -4.8                   -43.0                    29.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   95.9                    -0.1                   223.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    1.5                     0.0                    70.4
             Bering Sea          Sea of Okhotsk              Total Area
                   14.3                     9.0                   460.0


Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1380 on: December 11, 2014, 08:48:44 AM »
The ice in the Fram Strait that was in reverse has turned to the normal direction. You can see that some ice in the Barents Sea has retreated into the central Arctic. This retreat leaves some open water north of Franz Josef Land.

(needs a click to animate)

Laurent

  • ASIF Governor
  • Posts: 2525
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1381 on: December 11, 2014, 05:26:29 PM »
That's pretty mad, it does look like a spring melting on the Atlantic side of the Arctic.

http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictn_nowcast_anim30d.gif

jdallen

  • ASIF Upper Class
  • Posts: 2434
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1382 on: December 11, 2014, 06:03:22 PM »
That's pretty mad, it does look like a spring melting on the Atlantic side of the Arctic.

http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticictn_nowcast_anim30d.gif
They were not all hurricanes, but the North Atlantic has been getting hammered repeatedly this fall by huge powerful storms. 

There has been a considerable positive SST anomaly off the US eastern seaboard as well - the Gulf of Maine has been hot enough cold water fisheries are collapsing.  I'm certain that energy is giving a 'kick' to systems as they pass over it.

So, while it looks like spring melt, it's something new and different, and possibly a harbinger of a new staus quo, weather wise.
This space for Rent.

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1383 on: December 13, 2014, 02:22:38 PM »
Chukchi has long resisted the unavoidable but is now freezing over fast.

viddaloo

  • ASIF Upper Class
  • Posts: 1302
  • Hardanger Sometimes
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1384 on: December 14, 2014, 03:54:59 AM »
The ice in the Fram Strait that was in reverse has turned to the normal direction. You can see that some ice in the Barents Sea has retreated into the central Arctic. This retreat leaves some open water north of Franz Josef Land.

Open water prevails and expands north of Josef's Land and Severnaya, and you can even see the ice cracking up and leaving open water east of Novaya Semlya, so this seems like a good old thaw, and not just a consequence of drift/reversal. My guess is the Atlantic and its Gulf Stream is melting this ice, and it will be interesting to follow as this mild 'winter' progresses.
[]

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1385 on: December 18, 2014, 08:25:48 AM »
Update 20141217.
Changes from 20141210.

Extent: +380.7 (+28k vs 2013, +598k vs 2012)
Area: +292.2 (-89k vs 2013, +598k vs 2012)

Commenting the changes in the week from December 10-17.
Refreezing continues at a rate of about +70k/day for extent, area a bit less. This keeps total ice extent/area in 2014 at about the same levels as in 2013. The gap with 2012 has increased, mostly due to a stall in that year.
The biggest increase occurred in the Chukchi Sea, as this region is now nearly 100% covered by sea ice a decrease in the growth rates may be expected next week.
The smaller increase in area is partly explained by a regional drop in area in the Kara Sea.
 
You will find the updated graphs in the top post

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   13.9                    11.7                   -18.9
               Kara Sea             Barents Sea           Greenland Sea
                  -47.5                   -20.8                     7.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   82.6                     0.7                    38.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    1.4                     0.0                   165.7
             Bering Sea          Sea of Okhotsk            Total Extent
                   57.3                    88.0                   380.7

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   12.8                    15.4                   -33.9
               Kara Sea             Barents Sea           Greenland Sea
                  -94.7                   -20.9                    15.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   76.8                     0.5                    14.6
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    0.4                     0.4                   199.6
             Bering Sea          Sea of Okhotsk              Total Area
                   48.8                    56.5                   292.2


Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1386 on: December 18, 2014, 08:32:55 AM »
Ice in the Kara is highly mobile and is moved by south and westerly winds caused by a cyclone centered over Svalbard.


viddaloo

  • ASIF Upper Class
  • Posts: 1302
  • Hardanger Sometimes
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1387 on: December 18, 2014, 09:47:54 AM »
OK, I'm convinced. But it seemed very strange that the newly open waters didn't immediately refreeze. But I'm satisfied now it's the cyclone, sorry.
[]

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1388 on: December 18, 2014, 10:44:40 AM »
Winds from the south-west quadrant should be relatively mild, explaining the slow refreeze.
There is a small blob of isolated ice in the Barents Sea that you can see shrinking and finally popping out of existence. That could well be melting, otherwise not so clear.

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1389 on: December 19, 2014, 07:55:47 AM »
The Fram Strait express is in full speed right now. The driving force is a semi permanent cyclone just north of the Victoria Channel.

(click to animate)

Neven

  • Administrator
  • ASIF Governor
  • *****
  • Posts: 4068
    • View Profile
    • Arctic Sea Ice Blog
Re: Home brew AMSR2 extent & area calculation
« Reply #1390 on: December 19, 2014, 08:51:55 AM »
If that keeps up for a while, volume as reported by PIOMAS might increase slower than previous years.

I love saying self-evident things.  ;D
Il faut cultiver notre jardin

jdallen

  • ASIF Upper Class
  • Posts: 2434
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1391 on: December 19, 2014, 05:49:31 PM »
If that keeps up for a while, volume as reported by PIOMAS might increase slower than previous years.

I love saying self-evident things.  ;D

I'll say!

I will note that the fast ice that used to be present at the NE cape of Greenland is gone. Previously, that tended to throttle the flow significantly.

That rapid movement.  Multi-day sequence I presume?  Thats 15-20,000 KM2/day of older ice getting dumped out to its certain demise.
« Last Edit: December 19, 2014, 06:10:26 PM by jdallen »
This space for Rent.

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1392 on: December 25, 2014, 08:11:34 AM »
Update 20141224.
Changes from 20141217.

Extent: +551.9 (+391k vs 2013, +704k vs 2012)
Area: +546.7 (+296k vs 2013, +784k vs 2012)

Commenting the changes in the week from December 17-24.
The expected slow down after the Chukchi froze completely has not happened. Instead a strong increase happened, nearly 80k/day. Lots where  regions are in the game, on the Pacific side Bering Sea and the Sea of Okhotsk started for the first time. On the Atlantic side the Baffin, Hudson and Barents regions grew strongly. Part of the explanation are the winds (see image), blowing from the Arctic towards the oceans. Transport into the Arctic is mostly from the continents.
 
You will find the updated graphs in the top post

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   27.7                     0.8                    16.5
               Kara Sea             Barents Sea           Greenland Sea
                   73.2                    93.4                   -14.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  147.2                    -0.3                    67.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -1.6                    -2.3                    11.8
             Bering Sea          Sea of Okhotsk            Total Extent
                   75.9                    56.3                   551.9

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   13.3                    -0.7                    30.6
               Kara Sea             Barents Sea           Greenland Sea
                  101.6                    75.0                    -0.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  158.0                    -0.2                    72.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -0.6                    -7.2                    22.5
             Bering Sea          Sea of Okhotsk              Total Area
                   39.0                    43.7                   546.7



Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1393 on: December 25, 2014, 08:16:48 AM »
Close up view of the freezing process starting in the Bering Sea.

(click to animate)

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1394 on: December 26, 2014, 03:16:31 PM »
Someone asked by mail to show a "long" animation of the Fram Strait (to judge the low total export this year). Since the resulting animated gif was over 30MB, I created a video.

See if this works:


Neven

  • Administrator
  • ASIF Governor
  • *****
  • Posts: 4068
    • View Profile
    • Arctic Sea Ice Blog
Re: Home brew AMSR2 extent & area calculation
« Reply #1395 on: December 26, 2014, 09:50:05 PM »
Wow, this is amazing! Really awesome, Wippie!

Look at all that transport during summer, not. I knew it was slow this year, but my goodness, was it slow. Are there any numbers on this? Or do you know who I could ask?
Il faut cultiver notre jardin

Gray-Wolf

  • ASIF Middle Class
  • Posts: 601
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1396 on: December 28, 2014, 12:56:14 PM »
I'm busy linking the UTube animation on other sites I frequent as I'd noted the low export through the Summer but folk are happier reading about 'recovery' and 'resilient ice' than looking for the extreme behaviours in the basin leading to two back to back years holding onto more ice?

If all we are seeing is 'weather variability' then what are the odds for 3 back to back years displaying broadly similar patterns? surely it is even more likely to see an 'average' year ( for export and melt) this coming melt season than we are to see another repeat? Or is there something more at play here and this is mother N's attempts at staunching the wound that is bleeding the basin dry of ice?

Should we see another year that proves good for retention then I'd be concerned that we are seeing a 'pattern change' that is running against the grain for the general rise in temps around the far north?

We all know that you cannot alter one aspect of the global weather patterns without it having impact further afield ( Butterflies wing and all that!) so could the past two years have been hinting at the changes now ongoing with global temps ( and the faux stalling of global temps since 98'?) and would any resumption in warming rates similar to those through the 80's and 90's have positive impacts for the Arctic?
KOYAANISQATSI

ko.yaa.nis.katsi (from the Hopi language), n. 1. crazy life. 2. life in turmoil. 3. life disintegrating. 4. life out of balance. 5. a state of life that calls for another way of living.
 
VIRESCIT VULNERE VIRTUS

werther

  • ASIF Middle Class
  • Posts: 705
    • View Profile
Re: Home brew AMSR2 extent & area calculation
« Reply #1397 on: December 28, 2014, 01:37:14 PM »
Thanks, Wipneus. Like Neven, I would welcome numbers for the difference in advection through Fram Strait. I wrestle with the same sort of questions Gray-Wolf puts in his topic. But after a lot of NCEP/NCAR daily/monthly composition-messing I feel compelled to post my opinion in this thread.

The stop in Fram Strait ice export during last summer coincides neatly with a persistent high pressure ridge over the East Greenland, Norwegian and Barentsz Seas. Low level winds were mainly South over the Jan Mayen-Fram Strait stretch and North/Northeast in the Frantsa Yosefa-Novaya Zemlya sector.
There was no mean direct input of Southwestern wind into the Barentsz Sea, which contributed to keep SST’s out there to the lowest in the last 10-14 years.
As I have supposed earlier, the main zone of consequences from continuing warming and GHG-emissions may have shifted for some time (FI the mid-latitudes, deeper ocean levels). I think if true, this is a temporary stage. Even when there’s some repetitive tendency in this stage, I find it almost impossible to imagine the same sort of weather-related pattern to emerge each coming melt season. 

When asked for an example of a stage, I’d point to Antarctica. The remarkable steady rise in sea ice extent over there, through the last decade, could be such a stage. Off late, there have been some credible explanations how this could have happened and why this cannot be seriously discussed as a form of ‘recovery’.

The geomorphology in the Arctic is very different. Feedbacks possibly contributing to a temporary stage in the Arctic are not comparable to those at work around Antarctica. What could be at work, though, is a change in the Overturning Circulation. It could at the same time contribute to grounding line retreat of Antarctic ice shelves and sea-ending glaciers as well as affect winter and summer atmospheric pressure configuration over the Arctic.

Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1398 on: January 01, 2015, 10:00:25 AM »
Update 20141231.
Changes from 20141224.

Extent: +130.5 (+25k vs 2013, +263k vs 2012)
Area: +194.5 (-76k vs 2013, +318k vs 2012)

Happy new year and best wishes for 2015!
I keep commenting the regional sea ice growth and declines - using AMSR2 based hi-res  sea ice concentration data provided by the kind people from the University of Hamburg - on a semi-regular intervals, this time on the changes in the week from December 24-31.
The expected slow down in ice growth has come this week. With the Arctic Basin and Hudson Bay completely frozen, most changes will occur in the Pacific and Atlantic edges. Average extent grew by 25k/day, area a bit faster. The levels are comparable with those in 2012 and about 300k above those in 2012. Winds from the Arctic still favor Fram Strait export, but in the Bering, Baffin and Barnts area's ice growth has (at least) stalled.

You will find the updated graphs in the top post

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   -8.3                     0.7                     3.6
               Kara Sea             Barents Sea           Greenland Sea
                    8.1                    72.7                    71.8
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -51.3                    -0.4                   -37.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -6.8                    -0.6                     2.9
             Bering Sea          Sea of Okhotsk            Total Extent
                  -11.2                    86.2                   130.5

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   15.1                     1.7                     7.2
               Kara Sea             Barents Sea           Greenland Sea
                   46.5                    87.8                    63.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                  -63.5                    -0.3                   -39.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -15.0                    -4.9                    -7.6
             Bering Sea          Sea of Okhotsk              Total Area
                   32.6                    70.6                   194.5


Wipneus

  • ASIF Governor
  • Posts: 3622
    • View Profile
    • Arctische Pinguin
Re: Home brew AMSR2 extent & area calculation
« Reply #1399 on: January 01, 2015, 10:07:12 AM »
Sea of Okhotsk. No need to guess where the wind is blowing from!

(a click kicks-off the animation)