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Steven

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Re: 2020 Sea ice area and extent data
« Reply #1100 on: July 26, 2020, 08:44:30 PM »
NSIDC daily sea ice area anomalies:





2020 is currently the lowest on record for the date.  We'll see whether it can stay below 2012 in the next week, as 2012 dropped very fast at the end of July and beginning of August.  The anomaly data are from Wipneus' site and have leap year corrections.

Juan C. García

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Re: 2020 Sea ice area and extent data
« Reply #1101 on: July 27, 2020, 05:31:51 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 26th, 2020:
     5,962,825 km2, a drop of -31,737 km2.
     2020 is the lowest on record.
     Highlighted 2020 & the 4 years with a daily lowest min in Sept. (2012, 2019, 2016 & 2007).
     In the graph are today's 10 lowest years.
     Source: https://ads.nipr.ac.jp/vishop/#/extent
« Last Edit: July 27, 2020, 05:45:15 AM 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.

Lord M Vader

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Re: 2020 Sea ice area and extent data
« Reply #1102 on: July 27, 2020, 05:32:15 AM »
July 26: 5,962,825 Km2. A small drop by -31,737 km2. 2020 is still lowest on record.

Alphabet Hotel

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Re: 2020 Sea ice area and extent data
« Reply #1103 on: July 27, 2020, 02:59:56 PM »
NSIDC daily extent

7-day average:  (6204 − 6710) / 7  =  −72
14-day average: (6204 − 7747) / 14  =  −110

2020-07-12  7.747
2020-07-13  7.473  −274
2020-07-14  7.308  −165
2020-07-15  7.188  −120
2020-07-16  7.078  −110
2020-07-17  6.954  −124
2020-07-18  6.789  −165
2020-07-19  6.710    −79
2020-07-20  6.600  −110
2020-07-21  6.475  −125
2020-07-22  6.330  −145
2020-07-23  6.301    −29
2020-07-24  6.311    +10
2020-07-25  6.246    −65
2020-07-26  6.204    −42

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1104 on: July 27, 2020, 03:19:52 PM »
Clapped out technology,
Dodgy internet.
Try again.
JAXA ARCTIC SEA ICE EXTENT:  5,962,825 KM2 as at 26-Jul-2020

- Extent loss on this day 32k, 46 k less than the average loss on this day (of the last 10 years) of 78k,
- Extent loss from maximum on this date is 8,485 k, 1,071 k, 14.4% more than the 10 year average of 7,414 k.
- Extent is at position #1 in the satellite record
- Extent is  422 k LESS than 2019,
- Extent is  870 k LESS than 2016,
- Extent is  549 k LESS than 2012
- Extent is  627 k LESS than 2007
_____________________________________________
On average 74.5% of melting from maximum to minimum done, and 50 days to minimum

Projections. (Table JAXA-Arc1)

Average remaining melt (of the last 10 years) would produce a minimum in Sept 2020 of 3.43 million km2, 0.25 million km2 above the 2012 minimum of 3.18 million km2.

For a record low, remaining melt needs to be  9.8% or more above average, as happened with remaining melt in just 2 years, 2012 & 2016.
For the minimum to be above 4.0 million km2,  remaining melt needs to be  22.6% or more below the previous 10 years average remaining melt.

In every year from 2007 to 2019 remaining melt results in an extent below 3.96 million km2, which was the 2nd lowest extent in 2019.

I also attach a table comparing current JAXA extent with previous years' minima.
______________________________
N.B. Click once on an image to make it full-size

"Para a Causa do Povo a Luta Continua!"
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"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1105 on: July 27, 2020, 07:06:57 PM »
NSIDC Total Area as at 26-Jul-2020 (5 day trailing average) 4,311,259 KM2         
         
Total Area         
 4,311,259    km2      
-514,774    km2   <   2010's average.
-206,261    km2   <   2019
-1,331,856    km2   <   2000's average.
         
Total Change   -108    k   loss
Peripheral Seas   -16    k   loss
Central Seas___   -92    k   loss
         
Peripheral Seas         
Okhotsk______   -1    k   loss
Bering _______   -1    k   loss
Hudson Bay___   -3    k   loss
Baffin  Bay____   -2    k   loss
St Lawrence___   -0    k   loss
Greenland____   -8    k   loss
Barents ______   -2    k   loss
         
Central Arctic  Ocean Seas         
Chukchi______   -15    k   loss
Beaufort_____   -7    k   loss
CAA_________   -21    k   loss
East Siberian__   -8    k   loss
Central Arctic_   -43    k   loss
Laptev_______    2    k   gain
Kara_________   -1    k   loss
         
Sea ice area loss on this day 108 k, 55 k more than the 2010's average loss of 53 k         
         
- 2020 area is at position #1 in the satellite record.         
- 2020 Area is 515 k less than the 2010's average         
- 2020 Area is 1,332 k less than the 2000's average         
- 2020 Area is 387 k less than 2016         
- 2020 Area is 206 k less than 2019          
- 2020 Area is 139 k less than 2012         
___________________________________________         
NSIDC Total EXTENT as at 26-Jul-2020 (5 day trailing average) 6,275,407 KM2         
         
NSIDC Sea ice EXTENT loss on this day 54 k, 19 k less than the 2010's average loss of 73k         
         
- 2020 EXTENT is at position #1 in the satellite record.         
- 2020 EXTENT is 952 k less than the 2010's average         
- 2020 EXTENT is 1,859 k less than the 2000's average         
- 2020 EXTENT is 983 k less than 2016         
- 2020 EXTENT is 474 k less than 2019          
- 2020 EXTENT is 740 k less than 2012
         
___________________________________________         
Note: Click once on each image to see it full-size         
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1106 on: July 27, 2020, 08:07:17 PM »
NSIDC Central Arctic Sea AREA Graph
"Para a Causa do Povo a Luta Continua!"
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"Damn, I wanted to see what happened next" (Epitaph)

Juan C. García

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Re: 2020 Sea ice area and extent data
« Reply #1107 on: July 27, 2020, 08:48:28 PM »
Usually, the NSIDC single day values are seeing without confidence. It is recommended to follow the NSIDC 5-day trailing average. But I decided to make an analysis with the single day values, just to try to understand how the Arctic sea ice is being hit by the storm.

It is interesting that according to NSIDC, almost all the regions lost extent and area. Only the Laptev increase on both, extent and area.

What I was expecting became true: the area figure doubles the lost that we have on extent.

It is the Central Arctic the one that receive the strongest hit on area and it is the Canadian Archipelago the one that had the biggest lost on both, extent and area. Chukchi, ESS, Beaufort and Greenland had also a kind of important lost on area.


It is 5-day trailing average.  :-[
« Last Edit: July 28, 2020, 12:32:17 AM 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.

Sambuccu

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Re: 2020 Sea ice area and extent data
« Reply #1108 on: July 27, 2020, 10:49:21 PM »
Are you sure, Juan, these data are single day values ?
They look identical to Gerontocrat's 5 days values.

Juan C. García

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Re: 2020 Sea ice area and extent data
« Reply #1109 on: July 28, 2020, 12:30:49 AM »
Are you sure, Juan, these data are single day values ?
They look identical to Gerontocrat's 5 days values.
You are right. Seems that they don't make public the single day value.  :(
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.

be cause

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Re: 2020 Sea ice area and extent data
« Reply #1110 on: July 28, 2020, 01:14:14 AM »
https://forum.arctic-sea-ice.net/index.php?action=dlattach;topic=2975.0;attach=277672;image

 just to note the rise in Laptev sia was the first by any of the 'central seas in 15 days . I believe that is a record since i've followed Gerontocrat's stats ! b.c.
2007 + 5 = 2012 + 4 = 2016 + 3 = 2019 + 2 = 2021 
 (phew)

Juan C. García

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Re: 2020 Sea ice area and extent data
« Reply #1111 on: July 28, 2020, 05:37:07 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 27th, 2020:
     5,918,919 km2, a drop of -43,906 km2.
     2020 is the lowest on record.
     Highlighted 2020 & the 4 years with a daily lowest min in Sept. (2012, 2019, 2016 & 2007).
     In the graph are today's 10 lowest years.
     Source: https://ads.nipr.ac.jp/vishop/#/extent
« Last Edit: July 28, 2020, 05:52:49 AM 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.

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1112 on: July 28, 2020, 11:31:05 AM »
JAXA ARCTIC SEA ICE EXTENT:  5,918,919 KM2 as at 27-Jul-2020

- Extent loss on this day 44k, 46 k less than the average loss on this day (of the last 10 years) of 90k,
- Extent loss from maximum on this date is 8,529 k, 1,025 k, 13.7% more than the 10 year average of 7,504 k.
- Extent is at position #1 in the satellite record
- Extent is  369 k LESS than 2019,
- Extent is  835 k LESS than 2016,
- Extent is  447 k LESS than 2012
- Extent is  579 k LESS than 2007
_____________________________________________
On average 75.4% of melting from maximum to minimum done, and 49 days to minimum

Projections. (Table JAXA-Arc1)

Average remaining melt (of the last 10 years) would produce a minimum in Sept 2020 of 3.47 million km2, 0.29 million km2 above the 2012 minimum of 3.18 million km2.

For a record low, remaining melt needs to be  12.0% or more above average, as happened with remaining melt in just 2 years, 2012 & 2016.
For the minimum to be above 4.0 million km2,  remaining melt needs to be  21.6% or more below the previous 10 years average remaining melt.

In every year from 2007 to 2019 remaining melt results in an extent below 3.96 million km2, which was the 2nd lowest extent in 2019.
______________________________
N.B. Click once on an image to make it full-size
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Alphabet Hotel

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Re: 2020 Sea ice area and extent data
« Reply #1113 on: July 28, 2020, 03:10:38 PM »
NSIDC daily extent

7-day average:  (6130 − 6600) / 7  =  −67
14-day average: (6130 − 7473) / 14  =  −96

2020-07-13  7.473
2020-07-14  7.308  −165
2020-07-15  7.188  −120
2020-07-16  7.078  −110
2020-07-17  6.954  −124
2020-07-18  6.789  −165
2020-07-19  6.710    −79
2020-07-20  6.600  −110
2020-07-21  6.475  −125
2020-07-22  6.330  −145
2020-07-23  6.301    −29
2020-07-24  6.311    +10
2020-07-25  6.246    −65
2020-07-26  6.204    −42
2020-07-27  6.130    −74

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1114 on: July 28, 2020, 03:14:27 PM »
NSIDC Total Area as at 27-Jul-2020 (5 day trailing average) 4,206,561 KM2         
         
Total Area         
 4,206,561    km2      
-566,888    km2   <   2010's average.
-264,542    km2   <   2019
-1,382,020    km2   <   2000's average.
         
Total Change   -105    k   loss
Peripheral Seas   -15    k   loss
Central Seas___   -90    k   loss
         
Peripheral Seas         
Okhotsk______   -0    k   loss
Bering _______    0    k   gain
Hudson Bay___   -4    k   loss
Baffin  Bay____   -3    k   loss
St Lawrence___    0    k   gain
Greenland____   -8    k   loss
Barents ______   -2    k   loss
         
Central Arctic  Ocean Seas         
Chukchi______   -9    k   loss
Beaufort_____   -14    k   loss
CAA_________   -20    k   loss
East Siberian__    1    k   gain
Central Arctic_   -49    k   loss
Laptev_______    2    k   gain
Kara_________   -1    k   loss
         
Sea ice area loss on this day 105 k, 52 k more than the 2010's average loss of 53 k         
         
- 2020 area is at position #1 in the satellite record.         
- 2020 Area is 567 k less than the 2010's average         
- 2020 Area is 1,382 k less than the 2000's average         
- 2020 Area is 442 k less than 2016         
- 2020 Area is 265 k less than 2019          
- 2020 Area is 191 k less than 2012         
___________________________________________         
NSIDC Total EXTENT as at 27-Jul-2020 (5 day trailing average) 6,235,472 KM2         
         
NSIDC Sea ice EXTENT loss on this day 40 k, 33 k less than the 2010's average loss of 73k         
         
- 2020 EXTENT is at position #1 in the satellite record.         
- 2020 EXTENT is 918 k less than the 2010's average         
- 2020 EXTENT is 1,812 k less than the 2000's average         
- 2020 EXTENT is 974 k less than 2016         
- 2020 EXTENT is 429 k less than 2019          
- 2020 EXTENT is 679 k less than 2012
         
___________________________________________         
Note: Click once on each image to see it full-size         
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1115 on: July 28, 2020, 04:18:56 PM »
NSIDC Central Arctic Sea - ice area continues it's impressive decline; now 2nd lowest in the satellite record. The question as always is will this translate into impressive sea ice extent decline. Not yet.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Steven

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Re: 2020 Sea ice area and extent data
« Reply #1116 on: July 28, 2020, 07:35:04 PM »
Seems that they don't make public the single day value.  :(

You can find the single-day NSIDC regional extent and area values on Wipneus' site.  I think this is the file you're looking for:

https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxhcmN0aXNjaGVwaW5ndWlufGd4OjJhYjU3ZGMzNjUxYjdhZTc

Juan C. García

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Re: 2020 Sea ice area and extent data
« Reply #1117 on: July 28, 2020, 09:26:17 PM »
Seems that they don't make public the single day value.  :(

You can find the single-day NSIDC regional extent and area values on Wipneus' site.  I think this is the file you're looking for:

https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxhcmN0aXNjaGVwaW5ndWlufGd4OjJhYjU3ZGMzNjUxYjdhZTc
Thank you, Steven.
I will look at them.  :)
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.

Juan C. García

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Re: 2020 Sea ice area and extent data
« Reply #1118 on: July 29, 2020, 05:47:04 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 28th, 2020:
     5,886,022 km2, a drop of -32,897 km2.
     2020 is the lowest on record.
     Highlighted 2020 & the 4 years with a daily lowest min in Sept. (2012, 2019, 2016 & 2007).
     In the graph are today's 10 lowest years.
     Source: https://ads.nipr.ac.jp/vishop/#/extent
« Last Edit: July 30, 2020, 05:34:33 AM 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.

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1119 on: July 29, 2020, 11:18:13 AM »
JAXA ARCTIC SEA ICE EXTENT:  5,886,022 KM2 as at 28-Jul-2020

- Extent loss on this day 33k, 48 k less than the average loss on this day (of the last 10 years) of 81k,
- Extent loss from maximum on this date is 8,562 k, 976 k, 12.9% more than the 10 year average of 7,585 k.
- Extent is at position #1 in the satellite record
- Extent is  304 k LESS than 2019,
- Extent is  799 k LESS than 2016,
- Extent is  407 k LESS than 2012
- Extent is  524 k LESS than 2007
_____________________________________________
On average 76.2% of melting from maximum to minimum done, and 48 days to minimum

Projections. (Table JAXA-Arc1)

Average remaining melt (of the last 10 years) would produce a minimum in Sept 2020 of 3.52 million km2, 0.34 million km2 above the 2012 minimum of 3.18 million km2.

For a record low, remaining melt needs to be  14.5% or more above average.

For the minimum to be above 4.0 million km2,  remaining melt needs to be  20.3% or more below the previous 10 years average remaining melt.

In every year from 2007 to 2019, with the exception of 2009, remaining melt results in an extent below 3.96 million km2, which was the 2nd lowest extent of 2019.

5 days in a row of extremely low extent gains has changed the picture somewhat
______________________________
N.B. Click once on an image to make it full-size
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1120 on: July 29, 2020, 03:30:00 PM »
NSIDC Total Area as at 28-Jul-2020 (5 day trailing average) 4,106,162 KM2         
         
Total Area         
 4,106,162    km2      
-614,542    km2   <   2010's average.
-314,845    km2   <   2019
-1,429,637    km2   <   2000's average.
         
Total Change   -100    k   loss
Peripheral Seas   -13    k   loss
Central Seas___   -87    k   loss
         
Peripheral Seas         
Okhotsk______    0    k   gain
Bering _______   -0    k   loss
Hudson Bay___   -0    k   loss
Baffin  Bay____   -0    k   loss
St Lawrence___    1    k   gain
Greenland____   -12    k   loss
Barents ______   -1    k   loss
         
Central Arctic  Ocean Seas         
Chukchi______   -4    k   loss
Beaufort_____   -9    k   loss
CAA_________   -17    k   loss
East Siberian__   -2    k   loss
Central Arctic_   -54    k   loss
Laptev_______    3    k   gain
Kara_________   -2    k   loss
         
Sea ice area loss on this day 100 k, 47 k more than the 2010's average loss of 53 k         
         
- 2020 area is at position #1 in the satellite record.         
- 2020 Area is 615 k less than the 2010's average         
- 2020 Area is 1,430 k less than the 2000's average         
- 2020 Area is 456 k less than 2016         
- 2020 Area is 315 k less than 2019          
- 2020 Area is 237 k less than 2012         
___________________________________________         
NSIDC Total EXTENT as at 28-Jul-2020 (5 day trailing average) 6,219,589 KM2         
         
NSIDC Sea ice EXTENT loss on this day 16 k, 59 k less than the 2010's average loss of 75k         
         
- 2020 EXTENT is at position #1 in the satellite record.         
- 2020 EXTENT is 860 k less than the 2010's average         
- 2020 EXTENT is 1,744 k less than the 2000's average         
- 2020 EXTENT is 913 k less than 2016         
- 2020 EXTENT is 345 k less than 2019          
- 2020 EXTENT is 591 k less than 2012

__________________________________________
Daily sea ice extent increased by 92k. But the Arctic is not freezing, sea ice is melting.
The gif by aluminium and the University of Bremen concentration images show the massive rearrangement of the ice in the central seas of the Arctic Ocean.

I suggest we are seeing not so much a ridiculously early halt to sea ice loss, but more of a rearranging of the deckchairs on the Titanic.   

      
___________________________________________         
Note: Click once on each image to see it full-size         
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1121 on: July 29, 2020, 03:45:16 PM »
NSIDC Central Arctic Sea Extent & Area graphs attached

Extent loss is low c.f. area, but even so, extent is 2nd lowest in the satellite record, area is lowest.
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1122 on: July 29, 2020, 03:54:10 PM »
More NSIDC Area Graphs. N.B. 5 day trailing average data

Area losses have stalled in the seas off the Russian shore, (having become killing fields for ice pushed into them?).  (no graphs attached).

Meanwhile, looks like at the moment no ice import from the Fram into the Greenland Sea. Hence large area losses have started.
Also looks like the persistent heat in the CAA is now doing a demolition job on the ice.

But ice area loss in the Beaufort remains modest at the moment.
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gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1123 on: July 29, 2020, 06:39:59 PM »
As, at he moment, extent ice losses are taking a breather, while area ice losses are not, here is   NSIDC Area data analysed as I d JAXA extent data.

NSIDC ARCTIC SEA ICE AREA:  4,106,162 KM2 as at 28-Jul-2020

- Area loss on this day 100k, 47 k more than the average loss on this day (of the last 10 years) of 53k,
- Extent loss from maximum on this date is 9,260 k, 761 k, 09.0% more than the 10 year average of 8,499 k.
- Extent is at position #1 in the satellite record
- Extent is  -315 k LESS than 2019
- Extent is  -456 k LESS than 2016
- Extent is  -237 k LESS than 2012
______________________________
On average 83.5% of melting from maximum to minimum done, and 48 days to minimum

Projections. (Table JAXA-Arc1)
Average remaining melt (of the last 10 years) would produce a minimum in Sept 2020 of 2.42 million km2, 0.17 million km2 above the 2012 minimum of 2.25 million km2.
________________________________________________________
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gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1124 on: July 29, 2020, 06:55:37 PM »
NSIDC AREA data - a bit more..

The PLUME of minima from the last 10 years remaining area losses show that while the remaining area losses of 2012 and 2016 would produce a record low area, the same cannot be said for 2019.

With a range of outcomes spanning 0.8 million km2, for me it's far too early to be confident of any outcome.

The TABLE shows the current day's sea ice area compared with the minima of previous years.
Area is already blow the 1980's and 1990's minima, and the minima of the years 2000 to 2006.
Another 53k of area loss and its goodbye to the 2000's average minima.

Then there is a large gap of well over 400k to the next lowest minimum in 2013.

Tomorrow is another day
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Re: 2020 Sea ice area and extent data
« Reply #1125 on: July 29, 2020, 08:05:11 PM »
NSIDC daily extent

A gain of +92 today!

7-day average:  (6222 − 6475) / 7  =  −36
14-day average: (6222 − 7308) / 14  =  −78

2020-07-14  7.308
2020-07-15  7.188  −120
2020-07-16  7.078  −110
2020-07-17  6.954  −124
2020-07-18  6.789  −165
2020-07-19  6.710    −79
2020-07-20  6.600  −110
2020-07-21  6.475  −125
2020-07-22  6.330  −145
2020-07-23  6.301    −29
2020-07-24  6.311    +10
2020-07-25  6.246    −65
2020-07-26  6.204    −42
2020-07-27  6.130    −74
2020-07-28  6.222    +92

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Re: 2020 Sea ice area and extent data
« Reply #1126 on: July 29, 2020, 10:28:18 PM »
You can find the single-day NSIDC regional extent and area values on Wipneus' site.  I think this is the file you're looking for:

https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxhcmN0aXNjaGVwaW5ndWlufGd4OjJhYjU3ZGMzNjUxYjdhZTc
Thank you, Steven.
I will look at them.  :)

Glad it's useful. 

Maybe I should add that Wipneus uses a somewhat different definition of the regions than on the NSIDC website.  In particular, the CAB region as defined in Wipneus' data is about 38% larger than on the NSIDC website.

In addition, he has a spreadsheet with the daily regional NSIDC data for all previous days and years:

https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data/nsidc_arc_nt_detail.txt

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Re: 2020 Sea ice area and extent data
« Reply #1127 on: July 30, 2020, 03:00:13 AM »
You can find the single-day NSIDC regional extent and area values on Wipneus' site.  I think this is the file you're looking for:

https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxhcmN0aXNjaGVwaW5ndWlufGd4OjJhYjU3ZGMzNjUxYjdhZTc
Thank you, Steven.
I will look at them.  :)

Glad it's useful. 

Maybe I should add that Wipneus uses a somewhat different definition of the regions than on the NSIDC website.  In particular, the CAB region as defined in Wipneus' data is about 38% larger than on the NSIDC website.

In addition, he has a spreadsheet with the daily regional NSIDC data for all previous days and years:

https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data/nsidc_arc_nt_detail.txt
Thank you, Steven.
I have to check the numbers more carefully.
At a fast look, I get on July 28th.:  4.04M km2 for area, excluding lakes.
It is an interesting data set.
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.

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Re: 2020 Sea ice area and extent data
« Reply #1128 on: July 30, 2020, 05:33:49 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 29th, 2020:
     5,831,121 km2, a drop of -54,901 km2.
     2020 is the lowest on record.
     Highlighted 2020 & the 4 years with a daily lowest min in Sept. (2012, 2019, 2016 & 2007).
     In the graph are today's 10 lowest years.
     Source: https://ads.nipr.ac.jp/vishop/#/extent
« Last Edit: July 30, 2020, 05:45:58 AM 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.

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Re: 2020 Sea ice area and extent data
« Reply #1129 on: July 30, 2020, 06:32:13 AM »
This has been a good example of why it's good to use 5-day averages in the numbers. If there's a transient phenomenon changing the structure of remaining ice, both extent and area numbers get moderated. For area it's good since the melt ponds get mitigated and for the extent it's good since the 15% rule (there's ice extent even if there's only 15% of ice in the measurement block area)

That said, volume models are doing their own thing, and from the smoothness of their curves it can be said they use alternative methods of averaging. F.e. when there's an influx of warm water their curves do not show any fast movements in their numbers. But no doubt they attempt to smooth these over the month they report.

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Re: 2020 Sea ice area and extent data
« Reply #1130 on: July 30, 2020, 10:13:25 AM »
This has been a good example of why it's good to use 5-day averages in the numbers. If there's a transient phenomenon changing the structure of remaining ice, both extent and area numbers get moderated. For area it's good since the melt ponds get mitigated and for the extent it's good since the 15% rule (there's ice extent even if there's only 15% of ice in the measurement block area)

That said, volume models are doing their own thing, and from the smoothness of their curves it can be said they use alternative methods of averaging. F.e. when there's an influx of warm water their curves do not show any fast movements in their numbers. But no doubt they attempt to smooth these over the month they report.
Thank you -- this clear summary helps crystallize things for me.  I would only add that area and extent are based more directly on data whereas volume, as I understand it, is more modeled, using an array of measurements and assumptions.  So the nature of the model itself, rather than any averaging, may render volume less volatile.  Just shooting the breeze here, but these are different animals.
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Re: 2020 Sea ice area and extent data
« Reply #1131 on: July 30, 2020, 11:02:27 AM »
I have to check the numbers more carefully.
At a fast look, I get on July 28th.:  4.04M km2 for area, excluding lakes.
It is an interesting data set.

It should be 3.89 million km2 for 28 July 2020.  I'm not sure how you got 4.04 million km2?

Here are the single-day NSIDC area values for the last 10 days.  The table also shows the change from the previous day and the anomaly relative to the 1981-2010 average, in million km2.



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Re: 2020 Sea ice area and extent data
« Reply #1132 on: July 30, 2020, 12:35:58 PM »
JAXA ARCTIC SEA ICE EXTENT:  5,831,121 KM2 as at 29-Jul-2020

- Extent loss on this day 55k, 22 k less than the average loss on this day (of the last 10 years) of 77k,
- Extent loss from maximum on this date is 8,617 k, 954 k, 12.5% more than the 10 year average of 7,662 k.
- Extent is at position #1 in the satellite record
- Extent is  245 k LESS than 2019,
- Extent is  791 k LESS than 2016,
- Extent is  372 k LESS than 2012
- Extent is  531 k LESS than 2007
_____________________________________________
On average 77.0% of melting from maximum to minimum done, and 47 days to minimum

Projections. (Table JAXA-Arc1)

Average remaining melt (of the last 10 years) would produce a minimum in Sept 2020 of 3.54 million km2, 0.37 million km2 above the 2012 minimum of 3.18 million km2.

For a record low, remaining melt needs to be  16.0% or more above average.
For the minimum to be above 4.0 million km2,  remaining melt needs to be  20.0% or more below the previous 10 years average remaining melt.

In every year from 2007 to 2019, with the exception of 2009, remaining melt results in an extent below 3.96 million km2, which was the 2nd lowest extent of 2019.
______________________________
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gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1133 on: July 30, 2020, 04:39:41 PM »
NSIDC Total Area as at 29-Jul-2020 (5 day trailing average) 3,999,723 KM2         
         
Total Area         
 3,999,723    km2      
-674,231    km2   <   2010's average.
-371,569    km2   <   2019
-1,481,182    km2   <   2000's average.
         
Total Change   -106    k   loss
Peripheral Seas   -17    k   loss
Central Seas___   -90    k   loss
         
Peripheral Seas         
Okhotsk______    0    k   gain
Bering _______    0    k   gain
Hudson Bay___   -2    k   loss
Baffin  Bay____   -2    k   loss
St Lawrence___    0    k   gain
Greenland____   -12    k   loss
Barents ______   -1    k   loss
         
Central Arctic  Ocean Seas         
Chukchi______   -12    k   loss
Beaufort_____   -8    k   loss
CAA_________   -13    k   loss
East Siberian__   -7    k   loss
Central Arctic_   -50    k   loss
Laptev_______    2    k   gain
Kara_________   -2    k   loss
         
Sea ice area loss on this day 106 k, 59 k more than the 2010's average loss of 47 k         
         
- 2020 area is at position #1 in the satellite record.         
- 2020 Area is 674 k less than the 2010's average         
- 2020 Area is 1,481 k less than the 2000's average         
- 2020 Area is 480 k less than 2016         
- 2020 Area is 372 k less than 2019          
- 2020 Area is 289 k less than 2012         
___________________________________________         
NSIDC Total EXTENT as at 29-Jul-2020 (5 day trailing average) 6,175,097 KM2         
         
NSIDC Sea ice EXTENT loss on this day 44 k, 32 k less than the 2010's average loss of 76k         
         
- 2020 EXTENT is at position #1 in the satellite record.         
- 2020 EXTENT is 829 k less than the 2010's average         
- 2020 EXTENT is 1,706 k less than the 2000's average         
- 2020 EXTENT is 891 k less than 2016         
- 2020 EXTENT is 311 k less than 2019          
- 2020 EXTENT is 524 k less than 2012
   
____________________________________________
Daily sea ice Area losses have been above 100k for 4 days in a row.
Total Area has been lowest in the satellite record for 7 days in a row.
Can't just be the sensors getting fooled, especially as the data is 5 day trailing average, which tends to smooth out oddities.

Total Extent has been lowest in the satellite record for 23 days in a row.
No matter what the final outcome, that's quite a bit of the unused part of the graph paper with a big fat line on it.

Below is a good example of why NSIDC was reluctant to produce daily extent (& area) daily change data for general consumption. Too erratic..
Daily extent change   
26/07/20   -0.042
27/07/20   -0.074
28/07/20 +0.091
29/07/20   -0.131
___________________________________________         
Note: Click once on each image to see it full-size         
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"Damn, I wanted to see what happened next" (Epitaph)

Juan C. García

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Re: 2020 Sea ice area and extent data
« Reply #1134 on: July 30, 2020, 04:55:09 PM »
It should be 3.89 million km2 for 28 July 2020.  I'm not sure how you got 4.04 million km2?

Here are the single-day NSIDC area values for the last 10 days.  The table also shows the change from the previous day and the anomaly relative to the 1981-2010 average, in million km2.
Thanks Steven.

This is the table that I was looking for (I made it now, there is no data for yesterday yet):
[Almost 500K km2 difference between the drop in area and the drop in extent].
Source: https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data/nsidc_arc_nt_detail.txt

P.S. I will look to give more data and correct orthographic errors [ :P ], when today's data is available.
« Last Edit: July 30, 2020, 05:09:31 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.

Alphabet Hotel

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Re: 2020 Sea ice area and extent data
« Reply #1135 on: July 30, 2020, 05:48:31 PM »
NSIDC daily extent

NSIDC changed 2020-07-28 from 6.222 to 6.221

7-day average:  (6090 − 6330) / 7  =  −34
14-day average: (6090 − 7188) / 14  =  −78

2020-07-15  7.188
2020-07-16  7.078  −110
2020-07-17  6.954  −124
2020-07-18  6.789  −165
2020-07-19  6.710    −79
2020-07-20  6.600  −110
2020-07-21  6.475  −125
2020-07-22  6.330  −145
2020-07-23  6.301    −29
2020-07-24  6.311    +10
2020-07-25  6.246    −65
2020-07-26  6.204    −42
2020-07-27  6.130    −74
2020-07-28  6.221    +91
2020-07-29  6.090  −131

Juan C. García

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Re: 2020 Sea ice area and extent data
« Reply #1136 on: July 31, 2020, 05:35:15 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 30th, 2020:
     5,778,313 km2, a drop of -52,808 km2.
     2020 is the lowest on record.
     Highlighted 2020 & the 4 years with a daily lowest min in Sept. (2012, 2019, 2016 & 2007).
     In the graph are today's 10 lowest years.
     Source: https://ads.nipr.ac.jp/vishop/#/extent
« Last Edit: July 31, 2020, 05:48:50 AM 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.

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1137 on: July 31, 2020, 11:03:52 AM »
JAXA ARCTIC SEA ICE EXTENT:  5,778,313 KM2 as at 30-Jul-2020

- Extent loss on this day 53k, 19 k less than the average loss on this day (of the last 10 years) of 72k,
- Extent loss from maximum on this date is 8,669 k, 935 k, 12.1% more than the 10 year average of 7,735 k.
- Extent is at position #1 in the satellite record
- Extent is  219 k LESS than 2019,
- Extent is  756 k LESS than 2016,
- Extent is  354 k LESS than 2012
- Extent is  522 k LESS than 2007
_____________________________________________
On average 77.7% of melting from maximum to minimum done, and 46 days to minimum

Projections. (Table JAXA-Arc1)

Average remaining melt (of the last 10 years) would produce a minimum in Sept 2020 of 3.56 million km2, 0.38 million km2 above the 2012 minimum of 3.18 million km2.

For a record low, remaining melt needs to be  17.4% or more above average.
For the minimum to be above 4.0 million km2,  remaining melt needs to be  19.8% or more below the previous 10 years average remaining melt.

In every year from 2007 to 2019, with the exception of 2009, remaining melt results in an extent below 3.96 million km2, which was the 2nd lowest extent of 2019.
______________________________
N.B. Click once on an image to make it full-size
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Re: 2020 Sea ice area and extent data
« Reply #1138 on: July 31, 2020, 03:29:58 PM »
NSIDC daily extent

7-day average:  (6069 − 6301) / 7  =  −33
14-day average: (6069 − 7078) / 14  =  −72

2020-07-16  7.078
2020-07-17  6.954  −124
2020-07-18  6.789  −165
2020-07-19  6.710    −79
2020-07-20  6.600  −110
2020-07-21  6.475  −125
2020-07-22  6.330  −145
2020-07-23  6.301    −29
2020-07-24  6.311    +10
2020-07-25  6.246    −65
2020-07-26  6.204    −42
2020-07-27  6.130    −74
2020-07-28  6.221    +91
2020-07-29  6.090  −131
2020-07-30  6.069    −21

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1139 on: July 31, 2020, 04:38:35 PM »
NSIDC Total Area as at 30-Jul-2020 (5 day trailing average) 3,902,406 KM2         
         
Total Area         
 3,902,406    km2      
-710,818    km2   <   2010's average.
-393,086    km2   <   2019
-1,519,079    km2   <   2000's average.
         
Total Change   -97    k   loss
Peripheral Seas   -15    k   loss
Central Seas___   -82    k   loss
         
Peripheral Seas         
Okhotsk______    0    k   gain
Bering _______    0    k   gain
Hudson Bay___   -2    k   loss
Baffin  Bay____   -1    k   loss
St Lawrence___    0    k   gain
Greenland____   -11    k   loss
Barents ______   -1    k   loss
         
Central Arctic  Ocean Seas         
Chukchi______   -13    k   loss
Beaufort_____   -17    k   loss
CAA_________   -6    k   loss
East Siberian__   -4    k   loss
Central Arctic_   -41    k   loss
Laptev_______    2    k   gain
Kara_________   -3    k   loss
         
Sea ice area loss on this day 97 k, 36 k more than the 2010's average loss of 61 k         
         
- 2020 area is at position #1 in the satellite record.         
- 2020 Area is 711 k less than the 2010's average         
- 2020 Area is 1,519 k less than the 2000's average         
- 2020 Area is 476 k less than 2016         
- 2020 Area is 393 k less than 2019          
- 2020 Area is 294 k less than 2012         
___________________________________________         
NSIDC Total EXTENT as at 30-Jul-2020 (5 day trailing average) 6,139,611 KM2         
         
NSIDC Sea ice EXTENT loss on this day 35 k, 51 k less than the 2010's average loss of 86k         
         
- 2020 EXTENT is at position #1 in the satellite record.         
- 2020 EXTENT is 779 k less than the 2010's average         
- 2020 EXTENT is 1,660 k less than the 2000's average         
- 2020 EXTENT is 829 k less than 2016         
- 2020 EXTENT is 251 k less than 2019          
- 2020 EXTENT is 453 k less than 2012
         
___________________________________________         
Note: Click once on each image to see it full-size         
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

Juan C. García

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Re: 2020 Sea ice area and extent data
« Reply #1140 on: August 01, 2020, 02:48:32 AM »
Maybe I should add that Wipneus uses a somewhat different definition of the regions than on the NSIDC website.  In particular, the CAB region as defined in Wipneus' data is about 38% larger than on the NSIDC website.

In addition, he has a spreadsheet with the daily regional NSIDC data for all previous days and years:

https://sites.google.com/site/arctischepinguin/home/sea-ice-extent-area/data/nsidc_arc_nt_detail.txt
Hi.

I made 2 analysis with the data from NSIDC provided by Wipneus. The first analysis looks to the changes from July 21st to July 30th. The true is that I choose the 21st just randomly, without a reason. The second analysis is from July 25th to July 30th. I think that July 25th was the beginning of the storm that had an impact on the ASI.

At first, after looking at the numbers, I did not know what to think. There is a bigger lost on area that it is on extent. I was expecting that. But the drops, in both analyses, are concentrated on the Central Arctic Basin, not on Chukchi and Beaufort.

On a 2nd thought, the drops on Chukchi and Beaufort were important when they are measure on percentage (2nd analysis). So, what I think is that the CAB had a hit north of Chukchi and Beaufort. I need to analyze the frontier of both seas versus the CAB, to see is that is true. But that is beyond the analysis that I am looking to do now.

I include the numbers of both analyses.
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.

Juan C. García

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Re: 2020 Sea ice area and extent data
« Reply #1141 on: August 01, 2020, 05:32:57 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

July 31st, 2020:
     5,756,384 km2, a drop of -21,929 km2.
     2020 is the lowest on record.
     Highlighted 2020 & the 4 years with a daily lowest min in Sept. (2012, 2019, 2016 & 2007).
     In the graph are today's 10 lowest years.
     Source: https://ads.nipr.ac.jp/vishop/#/extent
« Last Edit: August 02, 2020, 05:34:26 AM 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.

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1142 on: August 01, 2020, 10:59:58 AM »
JAXA ARCTIC SEA ICE EXTENT:  5,756,384 KM2 as at 31-Jul-2020


In the last week of July, extent loss stalled. On the melting thread the discussion rages as to whether this just conceals massive ice losses, or reflects real slowdown in sea ice melt.
Whatever the outcome, Arctic sea ice extent has been lowest in the satellite record for the entire month of July.


- Extent loss on this day 22k, 42 k less than the average loss on this day (of the last 10 years) of 64k,
- Extent loss from maximum on this date is 8,691 k, 893 k, 11.4% more than the 10 year average of 7,799 k.
- Extent is at position #1 in the satellite record
- Extent is  199 k LESS than 2019,
- Extent is  682 k LESS than 2016,
- Extent is  340 k LESS than 2012
- Extent is  475 k LESS than 2007
_____________________________________________
On average 78.4% of melting from maximum to minimum done, and 45 days to minimum

Projections. (Table JAXA-Arc1)

Average remaining melt (of the last 10 years) would produce a minimum in Sept 2020 of 3.60 million km2, 0.43 million km2 above the 2012 minimum of 3.18 million km2.

For a record low, remaining melt needs to be  19.8% or more above average.
For the 2020 minimum to be above the 2019 minimum of 3.96 million km2,  remaining melt needs to be  16.5% or more below the previous 10 years average remaining melt.

In every year from 2007 to 2019, with the exception of 2009, remaining melt results in an extent below 3.96 million km2, which was the 2nd lowest extent of 2019.
______________________________
N.B. Click once on an image to make it full-size
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1143 on: August 01, 2020, 11:12:01 AM »
Arctic sea ice extent has been lowest in the satellite record for the entire month of July.

The monthly average extent for July shows this well. Average extent at 7.01 million is 383k, or nearly 5 years annual trend reduction, below the linear trend, and 364k below 2019.

Note that 2019 was also a record low July monthly average, 74k below the previous record low year of 2011, and 112k below 2012. 
_______________________________________________
2012 is already for some months a footnote in history.
« Last Edit: August 01, 2020, 11:18:07 AM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1144 on: August 01, 2020, 03:05:27 PM »
NSIDC Total Area as at 31-Jul-2020 (5 day trailing average) 3,824,028 KM2         
         
Total Area         
 3,824,028    km2      
-721,755    km2   <   2010's average.
-391,607    km2   <   2019
-1,529,379    km2   <   2000's average.
         
Total Change   -78    k   loss
Peripheral Seas   -11    k   loss
Central Seas___   -68    k   loss
         
Peripheral Seas         
Okhotsk______    0    k   gain
Bering _______    0    k   gain
Hudson Bay___   -2    k   loss
Baffin  Bay____   -2    k   loss
St Lawrence___   -0    k   loss
Greenland____   -7    k   loss
Barents ______   -1    k   loss
         
Central Arctic  Ocean Seas         
Chukchi______   -11    k   loss
Beaufort_____   -19    k   loss
CAA_________    1    k   gain
East Siberian__   -5    k   loss
Central Arctic_   -33    k   loss
Laptev_______    1    k   gain
Kara_________   -2    k   loss
         
Sea ice area loss on this day 78 k, 11 k more than the 2010's average loss of 67 k         
         
- 2020 area is at position #1 in the satellite record.         
- 2020 Area is 722 k less than the 2010's average         
- 2020 Area is 1,529 k less than the 2000's average         
- 2020 Area is 448 k less than 2016         
- 2020 Area is 392 k less than 2019          
- 2020 Area is 261 k less than 2012         
___________________________________________         
NSIDC Total EXTENT as at 31-Jul-2020 (5 day trailing average) 6,106,140 KM2         
         
NSIDC Sea ice EXTENT loss on this day 33 k, 50 k less than the 2010's average loss of 83k         
         
- 2020 EXTENT is at position #1 in the satellite record.         
- 2020 EXTENT is 729 k less than the 2010's average         
- 2020 EXTENT is 1,611 k less than the 2000's average         
- 2020 EXTENT is 762 k less than 2016         
- 2020 EXTENT is 190 k less than 2019          
- 2020 EXTENT is 398 k less than 2012
         
___________________________________________         
Note: Click once on each image to see it full-size         
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1145 on: August 01, 2020, 03:39:01 PM »
A few NSIDC graphs - no comment as yet
"Para a Causa do Povo a Luta Continua!"
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Alphabet Hotel

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Re: 2020 Sea ice area and extent data
« Reply #1146 on: August 01, 2020, 04:21:35 PM »
NSIDC daily extent

7-day average:  (6036 − 6311) / 7  =  −39
14-day average: (6036 − 6954) / 14  =  −66

2020-07-17  6.954
2020-07-18  6.789  −165
2020-07-19  6.710    −79
2020-07-20  6.600  −110
2020-07-21  6.475  −125
2020-07-22  6.330  −145
2020-07-23  6.301    −29
2020-07-24  6.311    +10
2020-07-25  6.246    −65
2020-07-26  6.204    −42
2020-07-27  6.130    −74
2020-07-28  6.221    +91
2020-07-29  6.090  −131
2020-07-30  6.069    −21
2020-07-31  6.036    −33

blumenkraft

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Re: 2020 Sea ice area and extent data
« Reply #1147 on: August 01, 2020, 04:42:40 PM »
Another deep red month.

Click to enlarge.

Juan C. García

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Re: 2020 Sea ice area and extent data
« Reply #1148 on: August 02, 2020, 05:32:36 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

August 1st, 2020:
     5,717,878 km2, a drop of -38,506 km2.
     2020 is the lowest on record.
     Highlighted 2020 & the 4 years with a daily lowest min in Sept. (2012, 2019, 2016 & 2007).
     In the graph are today's 10 lowest years.
     Source: https://ads.nipr.ac.jp/vishop/#/extent
« Last Edit: August 02, 2020, 05:44:34 AM 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.

gerontocrat

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Re: 2020 Sea ice area and extent data
« Reply #1149 on: August 02, 2020, 10:25:35 AM »
JAXA ARCTIC SEA ICE EXTENT:  5,717,878 KM2 as at 01-Aug-2020

- Extent loss on this day 39k, 25 k less than the average loss on this day (of the last 10 years) of 64k,
- Extent loss from maximum on this date is 8,730 k, 868 k, 11.0% more than the 10 year average of 7,862 k.
- Extent is at position #1 in the satellite record
- Extent is  187 k LESS than 2019,
- Extent is  604 k LESS than 2016,
- Extent is  365 k LESS than 2012
- Extent is  465 k LESS than 2007
_____________________________________________
On average 79.0% of melting from maximum to minimum done, and 44 days to minimum

Projections. (Table JAXA-Arc1)

Average remaining melt (of the last 10 years) would produce a minimum in Sept 2020 of 3.63 million km2, 0.45 million km2 above the 2012 minimum of 3.18 million km2.

For a record low, remaining melt needs to be  21.6% or more above average.
For the 2020 minimum to be above the 2019 minimum of 3.96 million km2,  remaining melt needs to be  15.8% or more below the previous 10 years average remaining melt.

In every year from 2007 to 2019, with the exception of 2009, remaining melt results in an extent below 3.96 million km2, which was the 2nd lowest extent of 2019.
_______________________________
As each day of very low extent loss occurs, it becomes ever more unlikely that 2020 will be a record low minimum, and a bit less unlikely that the 2020 minimum will be above that of 2019.
______________________________
N.B. Click once on an image to make it full-size
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)