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Shared Humanity

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Re: Home brew AMSR2 extent & area calculation
« Reply #2950 on: June 15, 2017, 07:42:09 PM »
That animation is scary! The Atlantic side, despite gaining extent thru heavy transport from the CAB looks horrible. Northwest Passage will definitely be open for business and the Beaufort and Siberian side looks like it is being devastated.

If we have better than normal melt conditions for the remainder of this melt season, we will hit new minimums in every one of the sea ice metrics.

seaicesailor

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Re: Home brew AMSR2 extent & area calculation
« Reply #2951 on: June 15, 2017, 07:47:42 PM »
You do mean June rather than May, don't you?

not sure but i think he meant what he wrote but the dates were for june not for may, why should he post 1 months old data today, as i said, just assuming from logic but facts may tell another story, let's see what wip has to say.

howerver, these anims show very well how much of the 100% extent is really 100% hence what
those number at this time of the year and nowadays are (not) worth LOL

i love this gif, tells a big tale.
To take into account that Wipneus increases the contrast to the extreme to show warming events etc.
The albedo anomaly plot of Nico Sun tells us quite a different story.
As a matter of fact I find the ice pack quite compact and that extent is not misleading much from what is going on, as much as it can tell

Ice Shieldz

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Re: Home brew AMSR2 extent & area calculation
« Reply #2952 on: June 15, 2017, 08:21:05 PM »
Seaicesailor, by what metric or observation do you find the ice pack compact?

Shared Humanity, I share your sentiment. The lack of FDDs drained the pack of the life blood it needed to recover from the sorry state it was in toward the end of 2016, while the consistent storms/winds continue to deliver body blows.  Most people here emphasis the need for minimal insolation and heat, but the incessant body blows, even the moderate ones, need to stop IMO. The cumulative effect of all this has Arctic sea ice hanging on by a thread.

seaicesailor

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Re: Home brew AMSR2 extent & area calculation
« Reply #2953 on: June 15, 2017, 09:36:12 PM »
Seaicesailor, by what metric or observation do you find the ice pack compact?

Shared Humanity, I share your sentiment. The lack of FDDs drained the pack of the life blood it needed to recover from the sorry state it was in toward the end of 2016, while the consistent storms/winds continue to deliver body blows.  Most people here emphasis the need for minimal insolation and heat, but the incessant body blows, even the moderate ones, need to stop IMO. The cumulative effect of all this has Arctic sea ice hanging on by a thread.
Not compact, but relatively it is not as disperse as one could expect or as implied by other posters in the forum (with all due respect).

Coincidentally I just saw the compactness graph by Wipneus from the ASIG and guess which year is "the most compact" as of today (see plot using NSIDC area/extent data) from the 2012 to 2017 group plus 2007
Edit. This metric being from NSIDC reflects low level of surface melting as Nico Sun's map also does, not only how loose or tight the ice pack is overall (which still, in large areas of the Arctic, the ice pack seems pretty tight to me, , if so momentarily).
« Last Edit: June 15, 2017, 09:46:38 PM by seaicesailor »

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2954 on: June 16, 2017, 07:08:01 AM »
No 15th June data from Hamburg yet. Uni Bremen continues with big drops (mostly Baffin and Hudson) :


Regional Arctic Sea Ice Extent and Area calculated from Uni Bremen ASI AMSR2 concentration data
See ub_am2_3.125_arc.txt for more details
Date: 2017-06-15 12:00  Values in 1000 km^2

Extent (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4410.9   -2.4            828.7   -7.5            646.8   +2.0
               Kara Sea             Barents Sea           Greenland Sea
           606.7   -3.0            215.0   -8.3            524.3   +4.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           600.7  -58.5             17.1  -10.6            759.1  -27.3
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           687.7   -2.2            389.5   +6.0            302.3   -6.0
             Bering Sea          Sea of Okhotsk                   Lakes
            23.8   -8.8             38.2   +9.9            117.2  +32.1
          Other regions       Total (ex. lakes)
            90.9  -12.0          10141.8 -123.7

Area (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4342.0  +25.6            781.9   -7.4            593.7   -3.4
               Kara Sea             Barents Sea           Greenland Sea
           497.7   -3.4            147.4   -9.9            426.3   -4.8
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           493.0  -52.1              5.5   -4.2            522.6  -70.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           642.7  -10.6            351.9   +4.8            287.8   -5.5
             Bering Sea          Sea of Okhotsk                   Lakes
             8.7   -4.3             16.0   +4.7             64.6  +13.4
          Other regions       Total (ex. lakes)
            31.2   -5.0           9148.4 -146.2



Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2955 on: June 16, 2017, 12:19:30 PM »
10h00 UTC seems to be the new time for the Hamburg update:

Update 20170615.

Extent: -92.5 (+96k vs 2016, -254k vs 2015, -423k vs 2014, -819k vs 2013, +187k vs 2012)
Area: -128.2 (+258k vs 2016, -315k vs 2015, -249k vs 2014, -434k vs 2013, +297k vs 2012)

The regional changes are similar to those of Bremen, shown in the previous post. Attached the Hudson and Baffin battle fields.

magnamentis

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Re: Home brew AMSR2 extent & area calculation
« Reply #2956 on: June 16, 2017, 07:08:22 PM »
You do mean June rather than May, don't you?

not sure but i think he meant what he wrote but the dates were for june not for may, why should he post 1 months old data today, as i said, just assuming from logic but facts may tell another story, let's see what wip has to say.

howerver, these anims show very well how much of the 100% extent is really 100% hence what
those number at this time of the year and nowadays are (not) worth LOL

i love this gif, tells a big tale.
To take into account that Wipneus increases the contrast to the extreme to show warming events etc.
The albedo anomaly plot of Nico Sun tells us quite a different story.
As a matter of fact I find the ice pack quite compact and that extent is not misleading much from what is going on, as much as it can tell

thanks for adding a different possible and valid point of view on the subject while to see anything there "quite intact" i can hardly see. we gonna see, i think that quite soon we shall either way be able to talk about facts :-)
« Last Edit: June 16, 2017, 07:15:04 PM by magnamentis »
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Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2957 on: June 17, 2017, 03:33:33 PM »
No update from Hamburg today. Here is the report from calculations from Bremen (AMSR2 ASI 3.125km) sea ice concentration:


Regional Arctic Sea Ice Extent and Area calculated from Uni Bremen ASI AMSR2 concentration data
See ub_am2_3.125_arc.txt for more details
Date: 2017-06-16 12:00  Values in 1000 km^2

Extent (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4417.6   +5.4            834.2   +4.5            632.3  -15.8
               Kara Sea             Barents Sea           Greenland Sea
           628.7  +20.0            213.3   -4.3            532.0   +5.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           582.5  -21.1             12.0   -6.6            712.5  -50.7
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           689.9   -2.6            380.2  -10.3            306.8   +3.5
             Bering Sea          Sea of Okhotsk                   Lakes
            19.7   -5.9             39.5   -1.7             81.1  -41.0
          Other regions       Total (ex. lakes)
           109.8   +7.9          10111.0  -72.0

Area (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4354.2  +11.0            788.9   +6.1            551.7  -42.9
               Kara Sea             Barents Sea           Greenland Sea
           509.7  +10.3            151.4   +2.7            433.5   +5.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           487.2   -7.7              3.7   -2.3            491.9  -32.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           641.6   -5.6            339.5  -13.2            289.8   +1.4
             Bering Sea          Sea of Okhotsk                   Lakes
             6.8   -2.7             15.2   -2.2             50.9  -16.1
          Other regions       Total (ex. lakes)
            40.1   +4.4           9105.3  -67.7



Juan C. García

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Re: Home brew AMSR2 extent & area calculation
« Reply #2958 on: June 17, 2017, 04:05:33 PM »
Great information Wipneus! Thank you for all these work!  ;)

It is sad that there is not an institution -at least that I know- that has a page of area, like the one that we used to have with Chryosphere Today.

PS: We should ask Trump to assign budget to the Cryosphere Today Program, at the University of Illinois!  :o 8)
« Last Edit: June 17, 2017, 04:11:34 PM by Juan C. García »
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

Feeltheburn

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Re: Home brew AMSR2 extent & area calculation
« Reply #2959 on: June 17, 2017, 11:49:25 PM »

It is sad that there is not an institution -at least that I know- that has a page of area, like the one that we used to have with Chryosphere Today.

PS: We should ask Trump to assign budget to the Cryosphere Today Program, at the University of Illinois!  :o 8)

We could kill two birds with one stone - increase funding to U. of Ill. to keep up CT and help the state hopefully avoid BK!
Feel The Burn!

oren

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Re: Home brew AMSR2 extent & area calculation
« Reply #2960 on: June 17, 2017, 11:49:36 PM »
It is sad that there is not an institution -at least that I know- that has a page of area, like the one that we used to have with Chryosphere Today.

Not sure if this is helpful, but NSIDC is still producing regional area numbers.
Go to ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/ and download the file Sea_Ice_Index_Regional_Daily_Data_G02135_v2.1.xlsx

Juan C. García

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Re: Home brew AMSR2 extent & area calculation
« Reply #2961 on: June 18, 2017, 04:34:46 AM »
It is sad that there is not an institution -at least that I know- that has a page of area, like the one that we used to have with Chryosphere Today.

Not sure if this is helpful, but NSIDC is still producing regional area numbers.
Go to ftp://sidads.colorado.edu/DATASETS/NOAA/G02135/seaice_analysis/ and download the file Sea_Ice_Index_Regional_Daily_Data_G02135_v2.1.xlsx


Looks great, Oren! Thank you!  :)
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2962 on: June 18, 2017, 10:35:21 AM »
Numbers calculated from Uni Bremen AMSR2 ASI 3.125km show the melt is still strong, especially in the Hudson region:




Regional Arctic Sea Ice Extent and Area calculated from Uni Bremen ASI AMSR2 concentration data
See ub_am2_3.125_arc.txt for more details
Date: 2017-06-17 12:00  Values in 1000 km^2

Extent (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4423.8   +5.2            829.1   -5.6            629.7   -4.0
               Kara Sea             Barents Sea           Greenland Sea
           637.6   +7.0            204.3  -11.7            525.2   -8.3
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           582.2   -2.9             20.2   +5.7            663.7  -52.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           682.9  -11.4            371.3   -9.5            307.6   -0.0
             Bering Sea          Sea of Okhotsk                   Lakes
            20.1   -0.9             41.5   -0.6            114.6  +27.5
          Other regions       Total (ex. lakes)
            92.5  -27.8          10031.8 -116.7

Area (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4356.3   +1.2            773.2  -16.2            524.8  -28.1
               Kara Sea             Barents Sea           Greenland Sea
           529.3  +18.0            143.2   -9.5            428.2   -6.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           484.9   -3.8              7.6   +2.8            448.9  -44.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           631.0  -14.7            329.7  -10.3            289.4   -0.9
             Bering Sea          Sea of Okhotsk                   Lakes
             6.9   -0.5             14.6   -1.6             65.2  +11.4
          Other regions       Total (ex. lakes)
            33.8  -10.7           9001.8 -125.6



oren

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Re: Home brew AMSR2 extent & area calculation
« Reply #2963 on: June 18, 2017, 11:53:31 AM »
Laptev area has dropped 70k in two days.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2964 on: June 19, 2017, 08:07:16 AM »
Still no data from Uni Hamburg. Uni Bremen sea ice concentration (AMSR2 ASI 3.125km) says down, down down:


Regional Arctic Sea Ice Extent and Area calculated from Uni Bremen ASI AMSR2 concentration data
See ub_am2_3.125_arc.txt for more details
Date: 2017-06-18 12:00  Values in 1000 km^2

Extent (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4426.4   +1.3            823.2   -6.7            633.9   +2.7
               Kara Sea             Barents Sea           Greenland Sea
           629.3  -10.2            195.2  -11.6            512.5  -14.5
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           571.5  -13.6             13.1   -8.3            643.5  -25.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           675.6  -12.2            359.9  -12.3            304.5   -4.1
             Bering Sea          Sea of Okhotsk                   Lakes
            24.5   +2.2             42.8   -1.9             79.9  -39.7
          Other regions       Total (ex. lakes)
            94.8   -5.7           9950.5 -120.0

Area (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4357.3   -0.3            749.5  -24.1            502.9  -23.0
               Kara Sea             Barents Sea           Greenland Sea
           514.4  -16.2            137.2   -7.2            409.3  -20.3
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           471.7  -15.2              4.9   -3.2            419.7  -31.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           629.9   -5.8            319.8  -10.4            285.4   -4.7
             Bering Sea          Sea of Okhotsk                   Lakes
             8.5   +0.8             15.6   -0.4             49.4  -18.2
          Other regions       Total (ex. lakes)
            34.3   -2.4           8860.5 -164.4


DavidR

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Re: Home brew AMSR2 extent & area calculation
« Reply #2965 on: June 19, 2017, 10:16:25 AM »
AMSR extent decline (~ 780K) over the past 6 days has been almost double that of IJIS (~400K). I realise that the two are measured differently however is there a known reason for this discrepancy which seems particularly large. 

binntho

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Re: Home brew AMSR2 extent & area calculation
« Reply #2966 on: June 19, 2017, 11:19:14 AM »
Been wondering the same thing ...

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2967 on: June 19, 2017, 12:15:22 PM »
AMSR extent decline (~ 780K) over the past 6 days has been almost double that of IJIS (~400K). I realise that the two are measured differently however is there a known reason for this discrepancy which seems particularly large.

You cannot compare the absolute Bremen and Hamburg numbers. The daily change numbers should be pretty similar though.

Bremen has dropped in 6 days about 577k, NSIDC 581k and Jaxa (single day) 454k.

So Jaxa is somewhat of an outlier but not nearly by a factor of two. And we have noticed this in previous melting seasons: Jaxa is often a bit slow in following big drops, the ASI algorithm (both Hamburg and Bremen) may be a bit too fast but after a few days they always come together. NSIDC often follows its own short-term course, but in the long term does not stray too far.


DavidR

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Re: Home brew AMSR2 extent & area calculation
« Reply #2968 on: June 19, 2017, 10:34:50 PM »
AMSR extent decline (~ 780K) over the past 6 days has been almost double that of IJIS (~400K). I realise that the two are measured differently however is there a known reason for this discrepancy which seems particularly large.

You cannot compare the absolute Bremen and Hamburg numbers. The daily change numbers should be pretty similar though.

Bremen has dropped in 6 days about 577k, NSIDC 581k and Jaxa (single day) 454k.

So Jaxa is somewhat of an outlier but not nearly by a factor of two. And we have noticed this in previous melting seasons: Jaxa is often a bit slow in following big drops, the ASI algorithm (both Hamburg and Bremen) may be a bit too fast but after a few days they always come together. NSIDC often follows its own short-term course, but in the long term does not stray too far.

Wipneus. adding the last  6 days ( 13-18)  you  have posted from Uni Bremen I get an extent loss of 777k not  577k and only  399425 from IJIS (13-18).  Maybe I'm misreading something but it still looks like a very big difference

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2969 on: June 20, 2017, 08:48:22 AM »
Here is the current report on extent/area calculated from Uni Bremen AMSR2 ASI 3.125km sea ice concentration:


Regional Arctic Sea Ice Extent and Area calculated from Uni Bremen ASI AMSR2 concentration data
See ub_am2_3.125_arc.txt for more details
Date: 2017-06-19 12:00  Values in 1000 km^2

Extent (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4432.0   +4.7            827.7   +3.5            628.5   -6.3
               Kara Sea             Barents Sea           Greenland Sea
           628.0   -3.3            204.0   +5.9            509.1   -4.8
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           559.7  -13.7             13.4   -0.7            619.5  -27.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           674.5   -5.9            348.4  -12.3            300.1   -5.1
             Bering Sea          Sea of Okhotsk                   Lakes
            33.0   +6.3             40.1   -6.4            105.5  +17.5
          Other regions       Total (ex. lakes)
            86.6  -16.9           9904.6  -82.1

Area (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4344.2  -14.0            753.4   +3.1            497.0   -6.5
               Kara Sea             Barents Sea           Greenland Sea
           515.8   -0.1            141.3   +2.6            406.3   -4.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           465.7   -7.3              6.1   +1.0            411.5   -9.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           627.9   -6.3            309.2  -11.2            281.2   -4.6
             Bering Sea          Sea of Okhotsk                   Lakes
            11.6   +2.2             14.0   -3.0             52.4   +0.0
          Other regions       Total (ex. lakes)
            30.9   -6.7           8816.1  -64.9


Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2970 on: June 20, 2017, 09:09:09 AM »

Wipneus. adding the last  6 days ( 13-18)  you  have posted from Uni Bremen I get an extent loss of 777k not  577k and only  399425 from IJIS (13-18).  Maybe I'm misreading something but it still looks like a very big difference

Let me first explain my numbers:

1. in my reckoning that is 5 days. I compared data from 11-17 June.

2. Posted numbers for 13 and 18 June are 9.9505 and 10.3554. That is a difference of 0.4049, about 405k.

My guess is that you are adding all the delta's for the indicated days. That indeed gives a much higher number.

Hmm. Numbers do change sometimes after they are posted, sometimes new data from the source (Bremen) sometimes due to more data available for infilling of missing data.
I am surprised about the size of the effect though. I will have to check my calculations and follow the number change game for some time. I will let you know what I find.

DavidR

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Re: Home brew AMSR2 extent & area calculation
« Reply #2971 on: June 20, 2017, 11:08:00 AM »

Wipneus. adding the last  6 days ( 13-18)  you  have posted from Uni Bremen I get an extent loss of 777k not  577k and only  399425 from IJIS (13-18).  Maybe I'm misreading something but it still looks like a very big difference

Let me first explain my numbers:

1. in my reckoning that is 5 days. I compared data from 11-17 June.

2. Posted numbers for 13 and 18 June are 9.9505 and 10.3554. That is a difference of 0.4049, about 405k.

My guess is that you are adding all the delta's for the indicated days. That indeed gives a much higher number.

Hmm. Numbers do change sometimes after they are posted, sometimes new data from the source (Bremen) sometimes due to more data available for infilling of missing data.
I am surprised about the size of the effect though. I will have to check my calculations and follow the number change game for some time. I will let you know what I find.
The answer seems to be that  the one day changes quoted do not match the differences between the figures posted from day to  day.
eg.  the quoted differences between the 17th and the 18th add up to 120K but the arithmetical difference between the days for each region is only  81K.   

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2972 on: June 21, 2017, 08:17:09 AM »

The answer seems to be that  the one day changes quoted do not match the differences between the figures posted from day to  day.
eg.  the quoted differences between the 17th and the 18th add up to 120K but the arithmetical difference between the days for each region is only  81K.   

Yes, the problem is that I compute a too-low value for the date when it is the latest value. The next day, when it is not the latest anymore, the value is about 40k bigger.

The problem is illustrated by the attached image date 20170620. Note the blue pixels off the coast of the Laptev Sea, these are pixels with unavailable data. As part of the calculation I try to fill them in from the previous day (the 19th), but as is illustrated that does not work for a lot of pixels. Tomorrow with data from the next day available I can do more infilling and the calculated extent and area go up. This is exactly the algorithm that NSIDC uses, but their SIC maps don't have these feeble near-coastal pixels.

For the moment I stop reporting the Bremen data until I have some sort of solution in place.

FishOutofWater

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Re: Home brew AMSR2 extent & area calculation
« Reply #2973 on: June 21, 2017, 04:59:01 PM »
Wip, As a minimum it appears you will have to step back one day to get more pixels to deal with the feeble pixel problem. There's a reason the NSIDC reports seem to be delayed by a few days.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2974 on: June 22, 2017, 08:06:48 AM »
Filling in the feeble pixels with more past data makes the second day change much smaller (+2.5k for the 20th June) and perhaps less biased. I'll keep recording the actual changes in the coming days to see how reliable the data is.

For now I resume reporting the daily Uni Bremen AMSR2 ASI 3.125km derived area and extent:

Regional Arctic Sea Ice Extent and Area calculated from Uni Bremen ASI AMSR2 concentration data
See ub_am2_3.125_arc.txt for more details
Date: 2017-06-21 12:00  Values in 1000 km^2

Extent (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4408.0   -0.9            821.7   -7.9            615.3   -5.9
               Kara Sea             Barents Sea           Greenland Sea
           617.3   -0.8            193.7   -6.3            506.1   -8.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           531.6  -17.4             18.1   -5.0            578.2  -27.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           674.8   -2.1            325.5   -6.5            295.1   -8.5
             Bering Sea          Sea of Okhotsk                   Lakes
            38.9   -1.9             54.6  +17.5            102.5   -1.3
          Other regions       Total (ex. lakes)
           117.5  -16.5           9796.4  -97.8

Area (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4325.7   -4.1            730.5  -23.7            483.7   +8.7
               Kara Sea             Barents Sea           Greenland Sea
           504.2   +4.9            130.3   -0.5            411.3   -3.7
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           442.4   -8.4              7.0   -3.3            381.3   -9.2
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           612.7  -11.8            289.0   +0.1            271.7   -8.9
             Bering Sea          Sea of Okhotsk                   Lakes
            15.0   +0.1             22.1   +8.4             51.5   -4.3
          Other regions       Total (ex. lakes)
            45.5   -6.5           8672.4  -57.9


 

Lord M Vader

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Re: Home brew AMSR2 extent & area calculation
« Reply #2975 on: June 22, 2017, 08:10:27 AM »
Wipneus: those numbers for Okhotsk seems to be a glitch. That area seems to be bone dry for now.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2976 on: June 22, 2017, 08:19:13 AM »
Wipneus: those numbers for Okhotsk seems to be a glitch. That area seems to be bone dry for now.

We are too used to the quality of the Uni Hamburg data. And those of Jaxa I should add.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2977 on: June 23, 2017, 08:02:00 AM »
My report calculated from Uni Bremen sea ice concentration:


Regional Arctic Sea Ice Extent and Area calculated from Uni Bremen ASI AMSR2 concentration data
See ub_am2_3.125_arc.txt for more details
Date: 2017-06-22 12:00  Values in 1000 km^2

Extent (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4411.8   +3.8            818.4   -3.3            608.8   -6.6
               Kara Sea             Barents Sea           Greenland Sea
           618.5   +1.0            197.2   +3.4            511.1   +4.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           527.0   -4.8             22.2   +3.3            544.6  -34.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           675.9   +1.1            333.0   +7.5            302.2   +6.9
             Bering Sea          Sea of Okhotsk                   Lakes
            40.9   +1.6             32.5  -22.5            109.1   +5.7
          Other regions       Total (ex. lakes)
           120.3   +1.1           9764.5  -36.5

Area (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4328.3   +2.6            737.8   +7.3            491.6   +7.9
               Kara Sea             Barents Sea           Greenland Sea
           509.3   +5.0            128.0   -2.3            422.3  +11.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           439.1   -3.2              8.1   +1.2            340.6  -40.6
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           606.5   -6.1            301.2  +12.3            274.5   +2.8
             Bering Sea          Sea of Okhotsk                   Lakes
            15.5   +0.4             12.6   -9.4             60.6   +8.9
          Other regions       Total (ex. lakes)
            44.7   -0.7           8660.2  -11.8



Now the Okhotsk variability stays troublesome.  The problem is illustrated in attached animation. Fields of false ice appear and disappear. Difficult to filter from the most recent SIC map. That is why I prefer the Uni Hamburg data, unfortunately there have not come any data from that source for a couple of days.
« Last Edit: June 23, 2017, 08:07:28 AM by Wipneus »

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2978 on: June 24, 2017, 09:07:15 AM »
Regional Arctic Sea Ice Extent and Area calculated from Uni Bremen ASI AMSR2 concentration data
See ub_am2_3.125_arc.txt for more details
Date: 2017-06-23 12:00  Values in 1000 km^2

Extent (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4417.8   +6.0            808.1  -10.4            618.2   +9.4
               Kara Sea             Barents Sea           Greenland Sea
           618.0   -0.5            184.5  -12.8            494.3  -16.9
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           528.3   +1.0             15.7   -6.9            517.1  -28.0
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           680.0   +4.0            342.2   +9.1            291.9  -10.4
             Bering Sea          Sea of Okhotsk                   Lakes
            36.0   -5.1             37.7   +4.3            124.8  +12.3
          Other regions       Total (ex. lakes)
           128.3   +6.7           9718.0  -50.5

Area (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4324.5   -3.8            737.8   -0.0            493.5   +1.9
               Kara Sea             Barents Sea           Greenland Sea
           504.3   -4.8            121.2   -6.8            394.8  -27.6
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           440.5   +1.3              5.6   -2.5            336.6   -4.1
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           617.9  +11.5            299.4   -1.8            264.2  -10.4
             Bering Sea          Sea of Okhotsk                   Lakes
            14.3   -1.2             14.6   +1.9             72.0  +10.1
          Other regions       Total (ex. lakes)
            50.3   +5.7           8619.5  -40.8

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2979 on: June 25, 2017, 09:56:29 AM »
I have made a change to the calculation of extent and area from Bremen sea ice concentration. Applying the ocean/ice masks from NSIDC reduces some of the false ice in low-latitude regions (Okhotsk / St. Lawrence). The same masks that cause the first-of-the-month jumps in NSIDC extent.

The latest change report shows continuing extent dropping in the Hudson. Area is dropping all over the (proper) Arctic Basin:


Regional Arctic Sea Ice Extent and Area calculated from Uni Bremen ASI AMSR2 concentration data
See ub_am2_3.125_arc.txt for more details
Date: 2017-06-24 12:00  Values in 1000 km^2

Extent (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4418.8   +1.0            808.6   +0.5            619.4   +1.2
               Kara Sea             Barents Sea           Greenland Sea
           618.1   +0.0            172.6   -1.8            465.9  -20.1
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           551.9  +24.5             18.8   +6.9            455.6  -61.8
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           689.6   +9.6            339.1   -3.1            279.0  -13.0
             Bering Sea          Sea of Okhotsk                   Lakes
            32.5   +0.6             24.9   -6.8             84.3  -40.2
          Other regions       Total (ex. lakes)
             6.1  -32.5           9501.0  -94.9

Area (value, one day change):
   Central Arctic Basin       East Siberian Sea              Laptev Sea
          4298.4  -26.0            715.7  -22.2            483.9   -9.5
               Kara Sea             Barents Sea           Greenland Sea
           503.9   -0.4            112.0   -5.1            366.3  -25.3
Baffin/Newfoundland Bay            St. Lawrence              Hudson Bay
           461.7  +21.4              8.5   +4.0            295.7  -40.9
   Canadian Archipelago            Beaufort Sea             Chukchi Sea
           621.9   +3.9            284.9  -14.5            246.8  -17.2
             Bering Sea          Sea of Okhotsk                   Lakes
            12.5   -0.1              9.6   -2.8             43.2  -26.0
          Other regions       Total (ex. lakes)
             2.1  -14.9           8423.7 -149.6


Thawing Thunder

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Re: Home brew AMSR2 extent & area calculation
« Reply #2980 on: June 25, 2017, 02:54:23 PM »
The NSIDC-cliff starts to look frightening ...

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2981 on: June 26, 2017, 08:18:31 AM »
Even Jaxa shows the torching Beaufort.
« Last Edit: June 26, 2017, 08:25:04 AM by Wipneus »

Thawing Thunder

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Re: Home brew AMSR2 extent & area calculation
« Reply #2982 on: June 26, 2017, 10:05:26 AM »
If drift and melt work together, there could be an open way through the NE-passage before the end of the month. At least for a small boat.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2983 on: June 26, 2017, 12:29:38 PM »
The adjustment needed for 24th June due to the "feeble pixels" discussed a few was more than 40k in extent.
That is just too much to use Bremen sea ice concentration in day-to-day comparisons.

Until I have thought of, and implemented another "trick" (don't tell anyone) to reduce those day-to-day variations no more daily Bremen reports.

Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2984 on: June 26, 2017, 04:48:26 PM »
On Hamburg's ftp server appeared data for 25th June, first data since those from the 18th.

Extent and area calculated from it confirms that 2017 is in an exiting race with 2012 and 2016:

Extent: NA (+26k vs 2016, -551k vs 2015, -368k vs 2014, -852k vs 2013, -73k vs 2012)
Area: NA (+14k vs 2016, -459k vs 2015, -347k vs 2014, -738k vs 2013, -226k vs 2012)
 


Attached the 7-day delta of the Hudson and Baffin Bay regions where most of the melting took place.

jdallen

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Re: Home brew AMSR2 extent & area calculation
« Reply #2985 on: June 26, 2017, 07:39:46 PM »
Even Jaxa shows the torching Beaufort.
Direct sun plus bottom heat plus warm 2M temps could translate to 10 CM/day coming off some areas of ice.  When do we expect that high to show up? How long will it hand around!?
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Neven

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Re: Home brew AMSR2 extent & area calculation
« Reply #2986 on: June 26, 2017, 09:30:03 PM »
According to ECMWF, the high will start to move over the Beaufort tomorrow, at 1015 hPa. This then becomes 1017-1023-1028 (with a second high starting over the Svalbard region)-1025-1022 hPa. Further out, the forecast has the Beaufort and Svalbard high merging, dominating the entire Arctic at 1030 hPa. But that is well beyond D6, so bound to change.

I'll post the 6-day forecast 12Z run later tonight in the melting season thread.
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Wipneus

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Re: Home brew AMSR2 extent & area calculation
« Reply #2987 on: Today at 04:57:33 PM »
Uni Hamburg is back! Most of the missing data has come in, hopefully the problems are solved up there.
Regarding the problems I faced with Bremen's data, I wait with publishing daily reports until I am satisfied that the UH data is indeed behaving much better.

In the mean time a side by side animated comparison of the CAA sea ice concentration 2016 and 2017.

Click to animate.
 

oren

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Re: Home brew AMSR2 extent & area calculation
« Reply #2988 on: Today at 05:19:36 PM »
In the mean time a side by side animated comparison of the CAA sea ice concentration 2016 and 2017.
Thanks Wipneus. 2016 seemed to be leading nicely in the main NW passage, until the last 48 hours turned it from what looked like undisturbed snow to very strong melt ponding (as also discussed in the buoy thread), now 2017 is in the lead.

Neven

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Re: Home brew AMSR2 extent & area calculation
« Reply #2989 on: Today at 05:23:21 PM »
Uni Hamburg is back! Most of the missing data has come in, hopefully the problems are solved up there.
Good news!
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FishOutofWater

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Re: Home brew AMSR2 extent & area calculation
« Reply #2990 on: Today at 05:59:56 PM »
All the snow last winter will have slowed the thickening of the ice. Now that the snow is gone the ice in the main channel will be very vulnerable to warm winds because it is not as thick as last year. Moreover, last summer's very warm weather took it's toll on the thick, multiyear ice in the CAA. Last fall started with thinner ice than fall 2015.

This year the thick ice in the CAA will be vulnerable to the early opening of the garlic press if the weather is warm there. It bears close watching.