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Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3200 on: August 16, 2017, 09:16:42 PM »
It looks to me like the area fluctuations at least in the Laptev bite are due to cloud.

Here is a Jaxa AMSR2 animation that is much less sensitive to  clouds/vapor.

A-Team

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Re: Home brew AMSR2 extent & area calculation
« Reply #3201 on: August 16, 2017, 11:54:49 PM »
Quote
Jaxa AMSR2 animation that is much less sensitive to  clouds/vapor.
The daily difference version, forward and back, is curious.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3202 on: August 17, 2017, 10:32:20 AM »
Crazy fluctuations in CAB area. Last three days: +95k, -117k and now +111k. I will say more about it in a second post. Extent is more reasonable, Greenland Sea drops most with smaller contributions on several fronts.

Update 20170816.

Extent: -82.2 (-45k vs 2016, -210k vs 2015, -697k vs 2014, -619k vs 2013, +721k vs 2012)
Area: +67.5 (+318k vs 2016, +130k vs 2015, -684k vs 2014, -416k vs 2013, +777k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -14.9                     4.3                    -4.8
               Kara Sea             Barents Sea           Greenland Sea
                  -17.9                    -0.9                   -37.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -1.1                     0.0                    -0.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -7.6                    -1.3                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -82.2

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  110.9                    -1.1                    -3.8
               Kara Sea             Barents Sea           Greenland Sea
                   -6.1                    -0.6                   -21.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -0.5                     0.0                    -0.6
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -4.7                    -4.8                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                    67.5



Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3203 on: August 17, 2017, 10:41:55 AM »
Attached the regional area graph of the CAB. Black=2017 UH AMSR2, purple is 2017 Jaxa.

Large swings are not unusual for UH AMSR2, but not in every year in the same amount.

Further the Jaxa data is much smoother and tends to follow the tops of the UH data. I am inclined to think that those (the tops) are a more realistic area value.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3204 on: August 17, 2017, 10:44:54 AM »
And the disappearance of sea ice in the Greenland Sea. Most of the remaining ice is is fast or only recently mobile.

oren

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Re: Home brew AMSR2 extent & area calculation
« Reply #3205 on: August 17, 2017, 10:56:21 AM »
Attached the regional area graph of the CAB. Black=2017 UH AMSR2, purple is 2017 Jaxa.

Large swings are not unusual for UH AMSR2, but not in every year in the same amount.

Further the Jaxa data is much smoother and tends to follow the tops of the UH data. I am inclined to think that those (the tops) are a more realistic area value.
Wipneus, do you have a chart of just the CAB JAXA area since 2012?
Even better, where can I download the regional JAXA area data? I couldn't find it on the web.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3206 on: August 17, 2017, 12:59:56 PM »
Attached the regional area graph of the CAB. Black=2017 UH AMSR2, purple is 2017 Jaxa.

Large swings are not unusual for UH AMSR2, but not in every year in the same amount.

Further the Jaxa data is much smoother and tends to follow the tops of the UH data. I am inclined to think that those (the tops) are a more realistic area value.
Wipneus, do you have a chart of just the CAB JAXA area since 2012?
Even better, where can I download the regional JAXA area data? I couldn't find it on the web.

Data for the graphic above is here:
https://sites.google.com/site/arctischepinguin/home/amsr2/data/Jaxa_AMSR2_L3_10km_Area_Extent-v0.0.txt

Notes:

- normally updates 24 hours after the others;
- total extent and area are calculated over the 14 well-known regions. E.g. Baltic, Maine and Alaska are ignored;
- no two day averages like ADS's product;
- apart from the above my day-to-day extent data is not exactly the same as ADS/Jaxa's numbers. Why that is I do not know yet.

oren

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Re: Home brew AMSR2 extent & area calculation
« Reply #3207 on: August 17, 2017, 02:23:21 PM »
Thank you Wipneus.

jdallen

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Re: Home brew AMSR2 extent & area calculation
« Reply #3208 on: August 18, 2017, 12:54:40 AM »
Crazy fluctuations in CAB area. Last three days: +95k, -117k and now +111k. I will say more about it in a second post. Extent is more reasonable, Greenland Sea drops most with smaller contributions on several fronts.

Update 20170816.

Extent: -82.2 (-45k vs 2016, -210k vs 2015, -697k vs 2014, -619k vs 2013, +721k vs 2012)
Area: +67.5 (+318k vs 2016, +130k vs 2015, -684k vs 2014, -416k vs 2013, +777k vs 2012)

I'm wondering if the fluctuation is a side effect of how granular the pack has become? Is it perhaps tied to the resolution limits of the sensing and computational systems? (E.g 12.5 KM grid)
This space for Rent.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3209 on: August 18, 2017, 10:07:18 AM »
Small extent uptick. The maps show that activity has not stopped. Drops on the Pacific front and increases to the ESS/Laptev side.

Update 20170817.

Extent: +12.3 (+74k vs 2016, -166k vs 2015, -612k vs 2014, -579k vs 2013, +772k vs 2012)
Area: -0.1 (+463k vs 2016, +121k vs 2015, -687k vs 2014, -415k vs 2013, +871k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                    7.2                     6.0                   -16.1
               Kara Sea             Barents Sea           Greenland Sea
                   -2.6                     1.0                     7.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    1.2                     0.0                    -0.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    4.2                     4.6                     0.1
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                    12.3

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                    5.4                     0.2                   -13.0
               Kara Sea             Barents Sea           Greenland Sea
                   -3.4                     0.1                     4.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    0.4                     0.0                    -0.6
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    0.5                     5.6                     0.1
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                    -0.1



Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3210 on: August 19, 2017, 03:12:03 PM »
A small uptick in extent, area declined some.

Update 20170818.

Extent: +6.9 (+158k vs 2016, -131k vs 2015, -536k vs 2014, -608k vs 2013, +813k vs 2012)
Area: -28.1 (+569k vs 2016, +64k vs 2015, -709k vs 2014, -594k vs 2013, +850k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   16.2                    -4.3                    -6.9
               Kara Sea             Barents Sea           Greenland Sea
                   -4.3                     4.2                    12.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -2.4                     0.0                     0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -9.3                     1.1                    -0.1
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                     6.9

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   14.1                   -22.0                    -6.3
               Kara Sea             Barents Sea           Greenland Sea
                   -4.9                     3.5                     5.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -1.7                     0.0                     0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -3.4                   -12.5                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   -28.1



Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3211 on: August 19, 2017, 03:15:16 PM »
Update of the CAA animation. I still see a lot of break up activity in the garlic press, it was not all that mobile as I thought.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3212 on: August 19, 2017, 03:32:01 PM »
Thank you for all this work, Wipneus.
I am very much surprised how resilient the Beaufort vestige of ice is turning out to be.
But based on Piomas thickness and SSTs over nearby waters, that should go before minimum.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3213 on: August 20, 2017, 10:43:15 AM »
Continuing net increasing extent and area. Regionally the declines are near (east) Beaofort and Laptev and increases near Chukchi and ESS.

Update 20170819.

Extent: +15.0 (+275k vs 2016, -15k vs 2015, -507k vs 2014, -564k vs 2013, +876k vs 2012)
Area: +29.8 (+639k vs 2016, +165k vs 2015, -588k vs 2014, -588k vs 2013, +898k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   25.2                    -2.4                    -9.7
               Kara Sea             Barents Sea           Greenland Sea
                   -2.7                     1.6                    -6.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    1.1                     0.0                     0.4
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   10.4                    -1.9                    -0.1
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                    15.0

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   39.0                     6.6                   -11.0
               Kara Sea             Barents Sea           Greenland Sea
                   -1.3                     1.0                    -3.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    0.7                     0.0                     0.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    2.1                    -4.5                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                    29.8


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3214 on: August 21, 2017, 06:32:29 PM »
And another regional century for the CAB, this time a decline. The two outstanding things at the moment: the continuing development of the "Beaufort Bite" (see attached delta map)  and the record low Greenland Sea sea ice cover, both measured as extent and area.

Update 20170820.

Extent: -20.8 (+253k vs 2016, +55k vs 2015, -488k vs 2014, -524k vs 2013, +993k vs 2012)
Area: -125.0 (+495k vs 2016, +134k vs 2015, -643k vs 2014, -658k vs 2013, +858k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -10.7                    -1.5                   -12.8
               Kara Sea             Barents Sea           Greenland Sea
                   -0.5                     0.9                    -3.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    0.8                     0.0                    -0.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    8.5                    -1.4                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -20.8

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                 -104.0                    -0.5                   -11.1
               Kara Sea             Barents Sea           Greenland Sea
                   -1.2                    -0.6                    -1.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    0.2                     0.0                    -0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    4.1                   -10.0                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                  -125.0


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3215 on: August 22, 2017, 06:08:37 PM »
Continuing with small declines. Lots of movements on small scale though, see the attached delta map.

Update 20170821.

Extent: -21.6 (+207k vs 2016, +53k vs 2015, -466k vs 2014, -466k vs 2013, +1045k vs 2012)
Area: -18.9 (+408k vs 2016, +113k vs 2015, -655k vs 2014, -594k vs 2013, +861k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -27.6                     3.1                    -9.9
               Kara Sea             Barents Sea           Greenland Sea
                    4.0                     2.2                    -8.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    3.1                     0.0                    -0.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   11.7                     0.4                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.1                     0.0                   -21.6

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -39.8                     1.6                   -10.2
               Kara Sea             Barents Sea           Greenland Sea
                    2.8                     4.3                    -3.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    1.9                     0.0                    -0.6
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   24.7                    -0.1                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.1                     0.0                   -18.9


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3216 on: August 22, 2017, 09:27:56 PM »
Quite an amazing stall in both weather (storms) and declines (extent & area). Do the large area fluctuations lately suggest the beginning of refreeze near the pole on some days?

To me, it looks to like various higher concentration arms are still in decline, and my guess is that the Beaufort arm will still melt out completely or nearly so. Also the CAA garlic press may rev up a bit soon. But with continuing nice weather in the forecast I doubt there will be much drama. Although boring, this is a good thing.

One interesting area is south of the Laptev polynya: will a channel form, all the way to open ocean?
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3217 on: August 23, 2017, 07:22:26 PM »
Small extent decline, area dropped some more.

Update 20170822.

Extent: -8.7 (+232k vs 2016, +110k vs 2015, -446k vs 2014, -421k vs 2013, +1027k vs 2012)
Area: -48.0 (+369k vs 2016, +70k vs 2015, -671k vs 2014, -551k vs 2013, +837k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -17.7                    -1.8                    -8.6
               Kara Sea             Barents Sea           Greenland Sea
                   -0.1                     1.9                    11.8
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    6.6                     0.0                     0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -0.4                    -0.7                     0.3
             Bering Sea          Sea of Okhotsk            Total Extent
                   -0.1                     0.0                    -8.7

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -37.7                     1.8                    -7.4
               Kara Sea             Barents Sea           Greenland Sea
                   -0.4                    -3.0                     8.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    3.2                     0.0                     0.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -15.6                     2.6                     0.3
             Bering Sea          Sea of Okhotsk              Total Area
                   -0.1                     0.0                   -48.0


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3218 on: August 24, 2017, 06:40:57 PM »
The CAA contributes most to the daily extent drop.

Update 20170823.

Extent: -52.1 (+262k vs 2016, +138k vs 2015, -472k vs 2014, -445k vs 2013, +1045k vs 2012)
Area: -1.3 (+373k vs 2016, +79k vs 2015, -600k vs 2014, -570k vs 2013, +860k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   -4.4                    -8.1                    -6.6
               Kara Sea             Barents Sea           Greenland Sea
                   -0.2                     2.1                    -5.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    2.7                     0.0                    -0.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -32.2                     1.1                    -0.2
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -52.1

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   20.3                    -4.4                    -5.0
               Kara Sea             Barents Sea           Greenland Sea
                    0.2                     2.1                    -7.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    3.3                     0.0                    -0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -16.3                     6.0                    -0.2
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                    -1.3


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3219 on: August 24, 2017, 06:42:25 PM »
Animation of the Canadian Archipelago.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3220 on: August 24, 2017, 08:38:21 PM »
Animation of the Canadian Archipelago.

The garlic is smashed and ready to be pressed, which is forecast to start slowly in about a day and intensify over several days.
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3221 on: August 25, 2017, 10:20:12 AM »
Lots of little changes up and down leading to small net losses which can be followed on the delta map.

Update 20170824.

Extent: -17.3 (+323k vs 2016, +158k vs 2015, -435k vs 2014, -429k vs 2013, +1127k vs 2012)
Area: +15.2 (+540k vs 2016, +103k vs 2015, -540k vs 2014, -489k vs 2013, +942k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   11.7                    -8.1                    -6.9
               Kara Sea             Barents Sea           Greenland Sea
                   -1.2                     2.7                     3.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -4.0                     0.0                    -0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -3.8                   -10.5                    -0.1
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -17.3

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   24.3                     3.9                   -11.7
               Kara Sea             Barents Sea           Greenland Sea
                   -1.7                     2.4                     3.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -1.9                     0.0                    -0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    0.0                    -3.6                    -0.1
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                    15.2


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3222 on: August 26, 2017, 06:57:15 PM »
A speed-up, at least for today. Ice retreating along the ice edge facing ESS,  in the CAA and near Svalbard.

Update 20170825.

Extent: -84.5 (+293k vs 2016, +111k vs 2015, -494k vs 2014, -484k vs 2013, +1138k vs 2012)
Area: -79.3 (+471k vs 2016, +45k vs 2015, -605k vs 2014, -504k vs 2013, +986k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -50.3                   -13.8                     2.0
               Kara Sea             Barents Sea           Greenland Sea
                   -2.3                    -4.8                    -4.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -2.3                     0.0                     0.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -10.5                     1.3                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -84.5

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -48.6                   -26.6                     4.4
               Kara Sea             Barents Sea           Greenland Sea
                   -0.8                    -3.9                     1.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -1.6                     0.0                     0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    3.9                    -7.8                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   -79.3


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3223 on: August 27, 2017, 07:57:57 PM »
Most of that loss from the edge facing ESS was regained again. Most of the loss was in the Greenland Sea anyway.

Update 20170826.

Extent: -15.4 (+365k vs 2016, +195k vs 2015, -438k vs 2014, -489k vs 2013, +1215k vs 2012)
Area: -96.5 (+377k vs 2016, -12k vs 2015, -587k vs 2014, -579k vs 2013, +983k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                    4.2                     2.2                     0.6
               Kara Sea             Barents Sea           Greenland Sea
                   -0.6                    -3.9                   -16.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    4.5                     0.0                     0.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -12.0                     5.8                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -15.4

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -50.3                     3.6                     4.5
               Kara Sea             Barents Sea           Greenland Sea
                   -0.8                    -1.4                   -14.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    1.9                     0.0                     0.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -33.3                    -6.4                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   -96.5



Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.


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Re: Home brew AMSR2 extent & area calculation
« Reply #3224 on: August 27, 2017, 07:59:27 PM »
Last years Chukchi "arm" compared with this year. Click for the animation.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3225 on: August 28, 2017, 05:58:06 PM »
You can see the current flowing towards Barrow canyon, the submarine canyon off of Pt. Barrow in the 2016 image. The thin line of ice perfectly outlines the current.

There's more ice this year but there's no evidence of the current towards Barrow canyon. It's open ocean. There's a big difference in the ocean currents between this year and last.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3226 on: August 28, 2017, 07:31:37 PM »
Continuing declines almost only in the CAB. The -3.7k loss in the Greenland Sea is more than 10% of its remaining extent.

Update 20170827.

Extent: -31.3 (+436k vs 2016, +326k vs 2015, -469k vs 2014, -484k vs 2013, +1188k vs 2012)
Area: -42.0 (+363k vs 2016, -15k vs 2015, -603k vs 2014, -578k vs 2013, +905k vs 2012)
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -33.7                     9.4                    -5.7
               Kara Sea             Barents Sea           Greenland Sea
                   -1.5                    -3.1                    -3.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    5.5                     0.0                     1.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    1.1                    -0.6                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -31.3

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -42.4                    10.9                    -8.7
               Kara Sea             Barents Sea           Greenland Sea
                    2.2                    -3.2                     0.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    5.6                     0.0                     1.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -6.0                    -1.7                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   -42.0


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

Rob Dekker

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Re: Home brew AMSR2 extent & area calculation
« Reply #3227 on: August 29, 2017, 08:20:40 AM »
Thanks Wipneus.
One question : your map suggests that the CAA seriously expanded in extent and area (lots of solid blue there) yet your numbers suggest that the CAA increased only 1.1 in extent and actually dropped 6.0 in 'area'. Why the discrepancy ?
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Re: Home brew AMSR2 extent & area calculation
« Reply #3228 on: August 29, 2017, 10:39:53 AM »
Educated guess: count blue and red pixels in CAA. I can see A LOT of red all over CAA. Similar with area, but here color means change of more than 7% - so it may be that bluish area is bigger by pixel count, but area increased there 8%, while other reddish areas decreased 50+% and overwhelmed increases.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3229 on: August 29, 2017, 07:06:54 PM »
Still substantial drops in extent and area. Area is currently third lowest in my limited data set, sharing the position with 2015. The fourth place in extent will not change soon.

Update 20170828.

Extent: -47.5 (+434k vs 2016, +349k vs 2015, -486k vs 2014, -488k vs 2013, +1185k vs 2012)
Area: -65.2 (+463k vs 2016, +2k vs 2015, -650k vs 2014, -606k vs 2013, +892k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -25.4                    -0.1                    -6.2
               Kara Sea             Barents Sea           Greenland Sea
                   -3.5                     0.5                     3.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -8.1                     0.0                     0.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -2.8                    -5.9                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -47.5

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -51.4                    -8.7                    -3.3
               Kara Sea             Barents Sea           Greenland Sea
                   -1.8                     1.0                     1.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -6.2                     0.0                     0.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -4.1                     6.9                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   -65.2


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3230 on: August 29, 2017, 07:49:33 PM »
Thanks Wipneus.
One question : your map suggests that the CAA seriously expanded in extent and area (lots of solid blue there) yet your numbers suggest that the CAA increased only 1.1 in extent and actually dropped 6.0 in 'area'. Why the discrepancy ?

Thanks for the questions Rob, I wondered if anyone does notice.

The delta images are taken created from the data as I download from the Uni Hamburg ftp server. The only processing that I do, as is intended by the creators of this data, is to apply a stationary land mask that  comes from the Uni Hamburg as well.

These data, lets call it "raw" data, show two obvious defects. The first one is the false ice along coastlines that you can observe are in all likeliness ice-free. This is due to land spillover of the microwave sensors. For area and extent calculations I filter these pixels away, based on the distance from the coast (few pixels) and from the ice free ocean (few pixels max away). I currently filter about 300k of extent away, and about 150k in area.

The second defect is what I call phantom ice, showing as an abrupt change of a cluster of pixels changing from on one day near zero concentration to a substantial value (>=17%).
Reason for this is unknown to me, but the favorite concentrations of such phantom ice are 50%, 33%, 25%, 20%, 17% gives an idea what could be happening.
I do filter such phantom ice before calculating extent and area. Note that if the ice was not phantom but a genuine uptick in ice cover, it will no longer be filtered the next day (since the zero ice condition on day one is no longer fulfilled).

Looking at the numbers for the CAA, I think the filters are doing a good job. But without the excellent and reliable quality of Uni Hamburgs data that would not have been possible. Uni Bremen has a similar product (AMSR2 ASI 3.125km) but it is proving much harder to get the smooth extent and area data from.

That should be some answer to your first question, the fact that we did not see a bump in today's report indicates that the filter algorithms must have worked well.

Why area and extent can go different directions is all in the definitions of area and extent. Area can in some cases change a lot without having any impact on extent (consolidated ice),  where in other cases (marginal ice) a small area drop can cause a big change in extent. The CAA contains both types of ice, so you are bound to see such variations.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3231 on: August 29, 2017, 09:35:13 PM »
Wipneus thanks for the detailed explanation, and for your endless supply of reliable data and analysis.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3232 on: August 30, 2017, 09:54:27 AM »
Thanks Wipneus, and yes, I think your 'phantom' ice filter is doing a good job.
It does mean that your AMSR2 numbers are 'delayed' by one day though, no ?
Also, does NSIDC apply a similar 'phantom' ice filter ?
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Re: Home brew AMSR2 extent & area calculation
« Reply #3233 on: August 30, 2017, 01:30:50 PM »
Looking at the numbers for the CAA, I think the filters are doing a good job. But without the excellent and reliable quality of Uni Hamburgs data that would not have been possible. Uni Bremen has a similar product (AMSR2 ASI 3.125km) but it is proving much harder to get the smooth extent and area data from.

Interesting! Any idea why?

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Re: Home brew AMSR2 extent & area calculation
« Reply #3234 on: August 30, 2017, 06:46:26 PM »
Extent declines in the CAA, Beaufort and in places along the CAB's edge.

Update 20170829.

Extent: -39.3 (+401k vs 2016, +366k vs 2015, -483k vs 2014, -483k vs 2013, +1158k vs 2012)
Area: +8.1 (+504k vs 2016, +94k vs 2015, -630k vs 2014, -686k vs 2013, +943k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   -6.2                     0.2                    -7.3
               Kara Sea             Barents Sea           Greenland Sea
                   -1.3                    -2.0                     6.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -1.9                     0.0                    -1.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -13.6                   -12.9                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -39.3

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   23.1                    -3.2                    -4.3
               Kara Sea             Barents Sea           Greenland Sea
                   -0.6                    -0.3                     3.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -0.6                     0.0                    -0.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -8.2                    -0.9                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                     8.1


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3235 on: August 30, 2017, 07:07:19 PM »
Thanks Wipneus, and yes, I think your 'phantom' ice filter is doing a good job.
It does mean that your AMSR2 numbers are 'delayed' by one day though, no ?


No, delays are for me not acceptable, if at the expense of some accuracy I try to minimize that. This is the timing:

So if the latest data is from day(n), I compare pixel-wise with day(n-1). If concentration on day(n-1) was near zero AND concentration on day (n) is >=17%  AND the concentration equals some surrounding pixels THEN the pixel probably contains phantom ice (so I set concentration to zero).

Quote
Also, does NSIDC apply a similar 'phantom' ice filter ?

No, this is finely tuned to repair a defect that I noticed in the Uni Hamburg product.

Perhaps the closest that NSIDC does is the manual quality control that is applied to their "final" data set, which can be done over a year after the measurement day.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3236 on: August 30, 2017, 07:31:21 PM »
Looking at the numbers for the CAA, I think the filters are doing a good job. But without the excellent and reliable quality of Uni Hamburgs data that would not have been possible. Uni Bremen has a similar product (AMSR2 ASI 3.125km) but it is proving much harder to get the smooth extent and area data from.

Interesting! Any idea why?

Why the products are different I do not know. But as a user of the data I have stumbled on some issues:
- There is more apparent pixel noise in Bremen's product
- There does not seem to be a fixed land mask. Pixels along the coast can at different days invalid (indicating land), or valid. Moreover there are many valid pixels that are zero where they should be near 100%. 
- The phantom ice is in Bremen SIC recognizable as well, timing an placing same as in Hamburg's product. But the uniform value of the phantom pixels that is a fingerprint in UH's product is not there (could be related to the first point). In other words, it is more difficult to distinguish from genuine ice.

 

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Re: Home brew AMSR2 extent & area calculation
« Reply #3237 on: August 30, 2017, 07:42:10 PM »
These data, lets call it "raw" data, show two obvious defects.

Terrific information, thanks!
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Re: Home brew AMSR2 extent & area calculation
« Reply #3238 on: August 31, 2017, 06:05:07 PM »
Small extent drops. Area losses are a but bigger, it seems the remaining ice in the Beaufort and some facing the Chukchi is taking a hit.

Update 20170830.

Extent: -19.1 (+501k vs 2016, +354k vs 2015, -459k vs 2014, -474k vs 2013, +1114k vs 2012)
Area: -35.2 (+544k vs 2016, +76k vs 2015, -589k vs 2014, -765k vs 2013, +864k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   -1.8                    -7.2                    -7.2
               Kara Sea             Barents Sea           Greenland Sea
                   -3.9                    -0.4                    -7.0
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    1.7                     0.0                    -0.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   14.7                    -7.5                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -19.1

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -20.6                    -5.4                    -3.9
               Kara Sea             Barents Sea           Greenland Sea
                   -4.7                    -0.1                    -3.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    1.3                     0.0                    -0.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   19.3                   -17.3                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   -35.2


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3239 on: August 31, 2017, 06:15:51 PM »
Update of the ice anaimation  along ice edge facing the ESS and Laptev. It goes slow but the edge is still pulling back.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3240 on: September 01, 2017, 07:55:04 PM »
Extent losses continue in the CAA and CAB. Most area was lost in the CAA.

Update 20170831.

Extent: -51.0 (+550k vs 2016, +346k vs 2015, -509k vs 2014, -521k vs 2013, +1159k vs 2012)
Area: -32.1 (+555k vs 2016, +46k vs 2015, -598k vs 2014, -788k vs 2013, +927k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -23.3                    -5.7                    -6.0
               Kara Sea             Barents Sea           Greenland Sea
                    0.3                    -3.5                     4.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -1.5                     0.0                    -0.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -17.4                     1.4                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -51.0

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   -5.3                    -2.5                    -5.6
               Kara Sea             Barents Sea           Greenland Sea
                    0.7                    -2.6                     5.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -2.0                     0.0                     0.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                  -22.8                     2.8                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   -32.1



Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3241 on: September 02, 2017, 07:17:57 PM »
Continuing declining extent and area. Mostly CAB and ESS.

Update 20170901.

Extent: -43.6 (+546k vs 2016, +337k vs 2015, -552k vs 2014, -558k vs 2013, +1121k vs 2012)
Area: -20.0 (+552k vs 2016, +59k vs 2015, -609k vs 2014, -793k vs 2013, +882k vs 2012)

The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -15.7                   -10.6                    -0.8
               Kara Sea             Barents Sea           Greenland Sea
                   -2.5                     0.3                    -0.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -5.5                     0.0                     0.4
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -2.7                    -6.6                     0.1
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                   -43.6

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  -15.4                    -9.7                    -0.8
               Kara Sea             Barents Sea           Greenland Sea
                   -1.9                    -0.3                    -2.3
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -3.6                     0.0                     0.4
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    8.1                     5.4                     0.1
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   -20.0


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3242 on: September 02, 2017, 07:22:19 PM »
A tiny bit of ice makes it to the Fram Strait, coming from north of Greenland.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3243 on: September 03, 2017, 05:29:55 AM »
Interesting watching the pull-back from Svalbard and the Barentsz.  Perhaps Atlantic water is making itself felt again now that the thickest of the MYI in the area has melted out, and is no longer being replenished from the pack.

If we get cyclones rolling up the coast, it will be interesting to see if the edge retreats back as it did last year, even as the interior froze.
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Re: Home brew AMSR2 extent & area calculation
« Reply #3244 on: September 03, 2017, 07:32:03 PM »
Increase of extent and even more so area. End of the melt season, minimum reached? That would be surprisingly early, bumps like these have sometimes reversed (2015).

Update 20170902.

Extent: +18.1 (+588k vs 2016, +347k vs 2015, -537k vs 2014, -504k vs 2013, +1191k vs 2012)
Area: +51.5 (+500k vs 2016, +82k vs 2015, -535k vs 2014, -724k vs 2013, +982k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   20.7                     0.3                    -1.0
               Kara Sea             Barents Sea           Greenland Sea
                   -0.8                    -2.2                     5.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -0.7                     0.0                    -0.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    4.7                    -7.2                    -0.1
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                    18.1

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   47.7                     2.2                    -1.7
               Kara Sea             Barents Sea           Greenland Sea
                   -0.7                    -1.7                     8.2
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                   -0.7                     0.0                    -0.5
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                    7.2                    -8.3                    -0.1
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                    51.5


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.

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Re: Home brew AMSR2 extent & area calculation
« Reply #3245 on: September 03, 2017, 07:53:30 PM »
"Increase of extent and even more so area. End of the melt season, minimum reached? That would be surprisingly early, bumps like these have sometimes reversed (2015)."

I dont think so, but if, it would not so much surprisingly... relativ cool august, early strong cool air production and a sector with much relativ low concentrated sea ice and therefore a good chance of early overfreeze. We saw this last year, where to the end, much ice going below 15% criteria and just a few weeks laster, strong increase of ice above 15% criteria.

Therefore, i would not be surprised if this was the End of melt season

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Re: Home brew AMSR2 extent & area calculation
« Reply #3246 on: September 03, 2017, 08:28:27 PM »
The two main locations of extent increase on the map are not the "classic first refreeze" areas, and do not have very cold temps at the moment, so I'd be surprised if this was it. We'll soon know though.
« Last Edit: September 03, 2017, 08:43:35 PM by oren »

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Re: Home brew AMSR2 extent & area calculation
« Reply #3247 on: September 03, 2017, 10:30:06 PM »
No.... The ESRL products did not show anything particularly indicative of refreezing for today.


Oh wait there was the helloutta snowing and -6C or lower in many areas of the CAB in their forecast, but I guess those were mistaken

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Re: Home brew AMSR2 extent & area calculation
« Reply #3248 on: September 04, 2017, 06:08:57 AM »
The extent increases were not due to refreeze. Both large areas are covered in low-concentration foam ice. For the Beaufort-side area, this was the first cloud-free day in several weeks -- probably the clouds interfered with the measurement somewhat. On the Atlantic side, that area only recently dropped below the 15% threshold, and again it may just be clouds messing with at least a few percentage points of concentration. Expect both these areas to drop back off the extent map before true refreeze takes hold.
The Permian–Triassic extinction event, a.k.a. the Great Dying, occurred about 250 million years ago and is the most severe known extinction event. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct; it is also the only known mass extinction of insects.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #3249 on: September 04, 2017, 05:31:53 PM »
I am convinced we see the effects of an early freezing period. It is seen by all sea ice concentration products that I follow, Jaxa melt ratio has plummeted and it is not untimely.
Now with temperatures that "hoover" ( I know I may not use the word correctly, hope you know what I mean) around the melt/freezing point it does not take big temperature rise to start melting again. The time for that is not long though.

Update 20170903.

Extent: +46.0 (+682k vs 2016, +351k vs 2015, -487k vs 2014, -419k vs 2013, +1259k vs 2012)
Area: +120.4 (+724k vs 2016, +212k vs 2015, -394k vs 2014, -574k vs 2013, +1142k vs 2012)
 
The details (in 1000 km2):


Extent:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                   42.3                    -4.0                    -0.3
               Kara Sea             Barents Sea           Greenland Sea
                   -1.3                     1.1                     7.4
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    2.1                     0.0                     0.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -5.1                     3.7                     0.0
             Bering Sea          Sea of Okhotsk            Total Extent
                    0.0                     0.0                    46.0

Area:
   Central Arctic Basin       East Siberian Sea              Laptev Sea
                  107.7                    14.3                     0.0
               Kara Sea             Barents Sea           Greenland Sea
                   -0.8                     0.7                     4.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
                    1.5                     0.0                     0.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
                   -8.0                     0.3                     0.0
             Bering Sea          Sea of Okhotsk              Total Area
                    0.0                     0.0                   120.4


Delta map attached: red/blue means the concentration went below/over the 15% cut-off. Reddish/bluish means the concentration decreased/increased by more than 7%.