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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2350 on: September 04, 2019, 10:55:02 AM »
JAXA ARCTIC SEA ICE EXTENT :-4,174,722 km2(September 3, 2019)

On this day extent loss increased to an above average 40k.
- Extent is 3rd lowest in the satellite record,
- Extent is 730 k greater than 2012, 121 k greater than 2016.
- Extent loss on this day 40 k, 19 k MORE than the average loss on this day of 21 k.
- Extent loss from maximum 10,097 k, 420 k (4.3%) greater than the average of 9,677 k loss from maximum by this day,
- Extent loss from maximum to date is still second highest in at least the last 12 years, only second to 2012,
- If extent loss stopped on this day, 2019 would be the 4th lowest minimum in the satellite record (just 2012, 2016 and 2007 less),
- On average 97.9% of the melting season done, with 10 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt (0.20 million km) would give a minimum of 3.97 million km2, 2nd lowest in the satellite record, 0.79 million km2 above the 2012 low of 3.18 million km2 and 0.05 million below the 2nd lowest in 2016 of 4.02 million km2.

Ice Melt Outlook The peak days of daily melt are past. From now to minimum, on average daily extent loss will gradually but erratically reduce until the minimum. 

Each day now consumes 9% of the average time available for further extent loss. However, in the the last 10 years there were as few as 4 days or as many as 18 days of extent losses to come.

Perhaps the final days of the season will ring the changes yet again. With very high SSTs and bottom melt still underway, this could provide the conditions for a later date of minimum as well as a slow refreeze (if surface weather conditions are at least not unfavourable)
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"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: 2019 sea ice area and extent data
« Reply #2351 on: September 04, 2019, 04:49:19 PM »
NSIDC Total Area as at 3 September 2019 (5 day trailing average)  2,935,250 km2

On this day the 5 day trailing average AREA decreased by 17k, (18k decrease the previous day). One-day NSIDC EXTENT loss 112k (21k, 97k, 73k & 58k the days before).
                        
Total Area         
 2,935,250    km2      
-239,024    km2   <   2010's average.
-441,826    km2   <   2018
-1,172,186    km2   <   2000's average.
         
Total Area Change   -17    k   loss
Peripheral Seas   -0    k   loss
Central Seas__   -13    k   loss
Other Seas___   -3    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____    0    k   gain
Greenland____    0    k   gain
Barents ______   -0    k   loss
         
CAB Seas         
Beaufort_____    5    k   gain
CAA_________   -8    k   loss
East Siberian__   -4    k   loss
Central Arctic_    0    k   gain
         
Kara_________   -0    k   loss
Laptev_______   -4    k   loss
Chukchi______   -2    k   loss
         
Other Seas         
Okhotsk______   -1    k   loss
St Lawrence___    -    k   loss
Hudson Bay___   -2    k   loss
- Area LOSS 18 k, 5 k less than the 2010's average area LOSS of 23 k on this day,
- Total area 3rd Lowest, 339 k MORE than 2016, and 506 k MORE than 2012, and now 2k LESS than the current minimum of 25th August, i.e. a new minimum.
________________________________________________________________________
Outlook
We are now well into the last few days of reducing and very variable daily area loss that that will slide to zero by around mid-September (or a bit later?).
"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: 2019 sea ice area and extent data
« Reply #2352 on: September 04, 2019, 05:06:26 PM »
NSIDC daily extent

blumenkraft

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Re: 2019 sea ice area and extent data
« Reply #2353 on: September 04, 2019, 05:12:03 PM »
Boom!
Refugees welcome

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #2354 on: September 04, 2019, 05:15:56 PM »
A late century drop in extent shows there are still possibilities for second lowest place ( in my limited data set).

NSIDC daily extent

An NSIDC daily extent drop of -112K km2, combined with the University of Hamburg century drop, as commented by Wipneus.

I wonder what will be the next ADS JAXA drop.
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.

blumenkraft

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Re: 2019 sea ice area and extent data
« Reply #2355 on: September 04, 2019, 06:24:34 PM »
Refugees welcome

Stephan

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Re: 2019 sea ice area and extent data
« Reply #2356 on: September 04, 2019, 10:28:54 PM »
The days of 5-10% daily area losses are back (ESS; Laptev)
It is too late just to be concerned about Climate Change

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #2357 on: September 05, 2019, 05:41:06 AM »
September 4th, 2019:
     4,158,349 km2, a drop of -16,373 km2.
     2019 is 3rd lowest on record.
     (2012 & 2016 highlighted).
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.

oren

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Re: 2019 sea ice area and extent data
« Reply #2358 on: September 05, 2019, 09:23:16 AM »
A late century drop in extent shows there are still possibilities for second lowest place ( in my limited data set).

NSIDC daily extent

An NSIDC daily extent drop of -112K km2, combined with the University of Hamburg century drop, as commented by Wipneus.

I wonder what will be the next ADS JAXA drop.
-16k... The numbers are not highly correlated day to day.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2359 on: September 05, 2019, 10:15:00 AM »
JAXA ARCTIC SEA ICE EXTENT :-   4,158,349 km2(September 4, 2019)

On this day extent loss decreased to a below average 16k.
- Extent is 3rd lowest in the satellite record,
- Extent is 744 k greater than 2012, 102 k greater than 2016.
- Extent loss on this day 16 k, 5 k less than the average loss on this day of 21 k.
- Extent loss from maximum 10,113 k, 415 k (4.3%) greater than the average of 9,697 k loss from maximum by this day,
- Extent loss from maximum to date is still second highest in at least the last 12 years, only second to 2012, but equal to 2008,
- If extent loss stopped on this day, 2019 would be the 4th lowest minimum in the satellite record (just 2012, 2016 and 2007 less),
- On average 98.1% of the melting season done, with 9 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt (0.18 million km) would give a minimum of 3.98 million km2, 2nd lowest in the satellite record, 0.80 million km2 above the 2012 low of 3.18 million km2 and 0.04 million below the 2nd lowest in 2016 of 4.02 million km2.

Ice Melt Outlook The peak days of daily melt are past. From now to minimum, on average daily extent loss will gradually but erratically reduce until the minimum. 

Each day now consumes 11 % of the average time available for further extent loss. However, in the the last 10 years there were as few as 3 days or as many as 17 days of extent losses to come.

Perhaps the final days of the season will ring the changes yet again. With very high SSTs and bottom melt still underway, this could provide the conditions for a later date of minimum as well as a slow refreeze (if surface weather conditions are at least not unfavourable)
____________________________________________________________
"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: 2019 sea ice area and extent data
« Reply #2360 on: September 05, 2019, 03:11:55 PM »
NSIDC Total Area as at 4 September 2019 (5 day trailing average)  2,915,980 km2

On this day the 5 day trailing average AREA decreased by 19k, (17k decrease the previous day). One-day NSIDC EXTENT loss 48k, 112k the day before.
                        
Total Area         
 2,915,980    km2      
-236,947    km2   <   2010's average.
-452,970    km2   <   2018
-1,173,314    km2   <   2000's average.
         
Total Area Change   -19    k   loss
Peripheral Seas   -4    k   loss
Central Seas__   -13    k   loss
Other Seas___   -3    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -1    k   loss
Greenland____   -3    k   loss
Barents ______    0    k   gain
         
CAB Seas         
Beaufort_____    9    k   gain
CAA_________   -9    k   loss
East Siberian__   -6    k   loss
Central Arctic_   -3    k   loss
         
Kara_________   -1    k   loss
Laptev_______   -1    k   loss
Chukchi______   -2    k   loss
         
Other Seas         
Okhotsk______   -2    k   loss
St Lawrence___    -    k   loss
Hudson Bay___   -1    k   loss
- Area LOSS 19 k, 3 k less than the 2010's average area loss of 22 k on this day,
- Total area 3rd Lowest, 365 k MORE than 2016, and 518 k MORE than 2012.
________________________________________________________________________
Outlook
We are now well into the last few days of reducing and very variable daily area loss that that will slide to zero by around mid-September (or a bit later?).
"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: 2019 sea ice area and extent data
« Reply #2361 on: September 05, 2019, 03:17:00 PM »
NSIDC daily extent

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2362 on: September 05, 2019, 03:25:23 PM »
NSIDC Total Area as at 4 September 2019 (5 day trailing average)  2,915,980 km2

Some more


Extent dropping faster than average, by a lot. Dispersion decreases as compaction concentration increases.

The Beaufort Sea has gone into reverse - area increasing quickly.

The CAA losing area quickly.
Could the Parry Channel end up clear but be blocked by ice in the Beaufort?

"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: 2019 sea ice area and extent data
« Reply #2363 on: September 05, 2019, 03:51:28 PM »
NSIDC ARCTIC SEA ICE EXTENT - 5 day trailing average:- 4,369,144  km2@ Sep 4, 2019

The last few days of strong daily extent losses are now fully incorporated into the 5 day data, so I thought to once again have a look at the data using the graphs & table formats I use for JAXA data.

- Extent is 3rd lowest in the satellite record,
- Extent is 791 k greater than 2012, 92 k greater than 2016.
- Extent loss on this day 68 k, 34 k more than the average loss on this day of 34 k.
- Extent loss from maximum 10,257 k, 357 k (3.6%) greater than the average of 9,900 k loss from maximum by this day,
- If extent loss stopped on this day, 2019 would be the 5th lowest minimum in the satellite record (just 2012, 2016 and 2007 and 2011 less),
- On average 97.8% of the melting season done, with 9 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining extent loss (0.22 million km) would give a minimum of 4.15 million km2, 3rd lowest in the satellite record, 0.76 million km2 above the 2012 low of 3.39 million km2.

Ice Melt Outlook The peak days of daily melt are past. From now to minimum, on average daily extent loss will gradually but erratically reduce until the minimum. 

Each day now consumes 11 % of the average time available for further extent loss. However, in the the last 10 years there were as few as 3 days or as many as 17 days of extent losses to come.
"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)

Stephan

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Re: 2019 sea ice area and extent data
« Reply #2364 on: September 05, 2019, 06:26:23 PM »
Analysis of seas with (almost) no ice Aug 31-Sep 04:
Okhotsk - 6,25 M km² (-78%)
Hudson - 7,05 M km² (-54%)
Bering - 0.40 M km² (-35%)
Barents - 1.21 M km² (-14%)
Baffin - 3.26 M km² (-27%)
sum      -18,17 M km² → looking at the small changes since Aug 20 these 18 M km² are relevant.

Will they finally find out that these seas are ice free? (at least Okhotsk and Bering?)

!! Edit: Sorry, I was too fast with this posting. Of course I am talking about k (not M) square kilometres!!
« Last Edit: September 05, 2019, 09:45:05 PM by Stephan »
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grixm

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Re: 2019 sea ice area and extent data
« Reply #2365 on: September 05, 2019, 06:31:22 PM »
Analysis of seas with (almost) no ice Aug 31-Sep 04:
Okhotsk - 6,25 M km² (-78%)
Hudson - 7,05 M km² (-54%)
Bering - 0.40 M km² (-35%)
Barents - 1.21 M km² (-14%)
Baffin - 3.26 M km² (-27%)
sum      -18,17 M km² → looking at the small changes since Aug 20 these 18 M km² are relevant.

Will they finally find out that these seas are ice free? (at least Okhotsk and Bering?)

They are well aware that those are ice-free. Kara too. But they can't manually adjust the readings because that would introduce subjectivity which ruins a lot of the scientific worth of the data.

Stephan

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Re: 2019 sea ice area and extent data
« Reply #2366 on: September 05, 2019, 09:02:06 PM »
I took the monthly extent value for August 2019 and added it into my long-term plot where I calculate the anomalies from 1979 up to now.
The average August extent is now 6,91 M km². August 2019 had an average extent of 5,03 M km², which is 1,88 M km² less than that average and the second lowest ever recorded since 1979, behind the record year 2012.
This low level also led the blue curve dive further below the red long term linear trend line by -0,62 M km² (calculated from the trend line this August should have been at 5,65 M km²).
The slope of the overall trend line has decreased by three digits compared to July 2019.

See attached graph.
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Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #2367 on: September 06, 2019, 05:44:23 AM »
September 5th, 2019:
     4,175,657 km2, an increase of 17,308 km2.
     2019 is 3rd lowest on record.
     (2012 & 2016 highlighted).
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: 2019 sea ice area and extent data
« Reply #2368 on: September 06, 2019, 10:50:39 AM »
JAXA ARCTIC SEA ICE EXTENT :- 4,175,657 km2(September 5, 2019)

Whoops. On this day extent loss increased by 17k.
- Extent is 3rd lowest in the satellite record,
- Extent is 810 k greater than 2012, 130 k greater than 2016.
- Extent gain on this day 17 k, 45 k different from the average loss on this day of 28 k.
- Extent loss from maximum 10,095 k, 370 k (3.8%) greater than the average of 9,725 k loss from maximum by this day,
- If extent loss stopped on this day, 2019 would be the 4th lowest minimum in the satellite record (just 2012, 2016 and 2007 less),
- On average 98.4% of the melting season done, with 8 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt (0.16 million km) would give a minimum of 4.02 million km2, equal 2nd lowest in the satellite record, 0.84 million km2 above the 2012 low of 3.18 million km2 and equal to the 2nd lowest in 2016 of 4.02 million km2.

Ice Melt Outlook The peak days of daily melt are past. From now to minimum, on average daily extent loss will gradually but erratically reduce until the minimum. 

Each day now consumes 12.5 % of the average time available for further extent loss. However, in the the last 10 years there were as few as 2 days or as many as 16 days of extent losses to come.

Despite this day's extent gain, very high SSTs and bottom melt could still provide the conditions for a later date of minimum as well as a slow refreeze (if surface weather conditions are at least not unfavourable)
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sja45uk

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Re: 2019 sea ice area and extent data
« Reply #2369 on: September 06, 2019, 01:50:20 PM »
This low level also led the blue curve dive further below the red long term linear trend line by -0,62 M km²
Stephen, what statistical tools did you use to establish that the trend is best modelled by a straight line?

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2370 on: September 06, 2019, 03:14:42 PM »
NSIDC Total Area as at 5 September 2019 (5 day trailing average)  2,909,863  km2

End of season wobbles rule, OK?....
On this day the 5 day trailing average AREA decreased by a measly 6k, .
One-day NSIDC EXTENT gain 46k, JAXA extent gain 17k

                        
Total Area         
 2,909,863    km2      
-224,291    km2   <   2010's average.
-451,867    km2   <   2018
-1,168,579    km2   <   2000's average.
         
Total Area Change   -6    k   loss
Peripheral Seas    1    k   gain
Central Seas__   -5    k   loss
Other Seas___   -2    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -1    k   loss
Greenland____    2    k   gain
Barents ______   -0    k   loss
         
CAB Seas         
Beaufort_____    14    k   gain
CAA_________   -6    k   loss
East Siberian__   -4    k   loss
Central Arctic_   -8    k   loss
         
Kara_________   -1    k   loss
Laptev_______   -1    k   loss
Chukchi______   -1    k   loss
         
Other Seas         
Okhotsk______   -1    k   loss
St Lawrence___    -    k   loss
Hudson Bay___   -1    k   loss
- Area LOSS 6 k, 15 k less than the 2010's average area loss of 21 k on this day,
- Total area 3rd Lowest, 395 k MORE than 2016, and 539 k MORE than 2012.
________________________________________________________________________
Outlook
We are now well into the last few days of reducing and very variable daily area loss that that will slide to zero by around mid-September (or a bit later?).
"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)

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Re: 2019 sea ice area and extent data
« Reply #2371 on: September 06, 2019, 03:20:38 PM »
NSIDC daily extent

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2372 on: September 06, 2019, 03:25:46 PM »
As far as AREA data is concerned, apart from the generally slow loss in area, the stories from individual seas are:-

- Beaufort Sea Area continues to increase strongly,
- while next door the CAA manages to continue losing area.
"Para a Causa do Povo a Luta Continua!"
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Re: 2019 sea ice area and extent data
« Reply #2373 on: September 06, 2019, 05:40:36 PM »
This low level also led the blue curve dive further below the red long term linear trend line by -0,62 M km²
Stephen, what statistical tools did you use to establish that the trend is best modelled by a straight line?
I have not made a detailed statistical analysis which type of trend line to use.
I attach the original one and a logarithmic trend line. The differences between them are marginal, R² is almost identical.
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Re: 2019 sea ice area and extent data
« Reply #2374 on: September 06, 2019, 10:36:07 PM »
End of season wobbles rule, OK?....
On this day the 5 day trailing average AREA decreased by a measly 6k, .
One-day NSIDC EXTENT gain 46k, JAXA extent gain 17k


The single daily NSIDC sea ice area value for 9.5 is 2,959,927 square kilometers (pole hole adjustment). 

This is a significant gain of 59,524 square kilometers from the previous day. This increase in the daily value, shows consistency with the sea ice gains for JAXA and NSIDC extent values.

If you remove 9.4 from the daily NSIDC area data set, 8.24 would have the lowest area value for the current melting season.

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #2375 on: September 07, 2019, 05:41:10 AM »
September 5th, 2019:
     4,176,087 km2, an increase of 430 km2.
     2019 is 3rd lowest on record.
     (2012 & 2016 highlighted).
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: 2019 sea ice area and extent data
« Reply #2376 on: September 07, 2019, 11:44:11 AM »
JAXA ARCTIC SEA ICE EXTENT :- 4,175,657 km2(September 5, 2019)

Whoops and a bit. Today extent increased by 0.4k, the previous day extent increased by 17k. Suddenly a minimum of less than 4 million km2 looks a long way away. 
- Extent is 3rd lowest in the satellite record,
- Extent is 851 k greater than 2012, 153 k greater than 2016.
- Extent gain on this day <1k, 31 k different from the average loss on this day of 31 k.
- Extent loss from maximum 10,095 k, 339 k (3.5%) greater than the average of 9,756 k loss from maximum by this day,
- If extent loss stopped on this day, 2019 would be the 4th lowest minimum in the satellite record (just 2012, 2016 and 2007 less),
- On average 98.7% of the melting season done, with 7 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt (0.16 million km) would give a minimum of 4.05 million km2, 3rd lowest in the satellite record, 0.87 million km2 above the 2012 low of 3.18 million km2 and 0.03 millon km2 greater than the 2nd lowest in 2016 of 4.02 million km2.

Ice Melt Outlook The peak days of daily melt are past. From now to minimum, on average daily extent loss will gradually but erratically reduce until the minimum. 

Each day now consumes 14 % of the average time available for further extent loss. However, in the the last 10 years there were as few as just 1 day or as many as 15 days of extent losses to come.

Despite this day's extent gain, very high SSTs and bottom melt could still provide the conditions for a later date of minimum as well as a slow refreeze (if surface weather conditions are at least not unfavourable). However, unfavourable seems to be the flavour of the moment.
____________________________________________________________
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2377 on: September 07, 2019, 11:53:28 AM »
JAXA ARCTIC SEA ICE EXTENT :- 4,175,657 km2(September 5, 2019)- MORE STUFF

I attach the plume of projections of minimum from the previous 10 years remaining melt. Keeps on moving up. Note 2018 - from now and into the freezing daily losses high to minimum, and low gains into the freezing season.

Also attached is the table of outcomes if the current minimum on 4 September holds.

Also attached is the graph of 365 day trailing averages. Still looks like a possible new record low in early 2020.
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sja45uk

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Re: 2019 sea ice area and extent data
« Reply #2378 on: September 07, 2019, 12:08:16 PM »
I attach the original one and a logarithmic trend line. The differences between them are marginal, R² is almost identical.
Thanks Stephan, that is an interesting result, and not what I expected from eyeballing them. However, I was never great at mathematics and am not sure how a log curve compares with a quadratic.

uniquorn

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Re: 2019 sea ice area and extent data
« Reply #2379 on: September 07, 2019, 12:50:49 PM »
Despite this day's extent gain, very high SSTs and bottom melt could still provide the conditions for a later date of minimum as well as a slow refreeze (if surface weather conditions are at least not unfavourable). However, unfavourable seems to be the flavour of the moment.
Perhaps it's time to go back to a comparison with 2018 on the chart

echoughton

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Re: 2019 sea ice area and extent data
« Reply #2380 on: September 07, 2019, 01:06:06 PM »
What's up with this site? Seems to be at odds with JAXA. Glitch showing massive losses lately???

http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/


grixm

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Re: 2019 sea ice area and extent data
« Reply #2381 on: September 07, 2019, 01:11:03 PM »
What's up with this site? Seems to be at odds with JAXA. Glitch showing massive losses lately???

http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

It 5-day average. Daily values are posted in this thread. https://forum.arctic-sea-ice.net/index.php/topic,2533.msg227125.html#msg227125

binntho

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Re: 2019 sea ice area and extent data
« Reply #2382 on: September 07, 2019, 01:29:56 PM »
What's up with this site? Seems to be at odds with JAXA. Glitch showing massive losses lately???

http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

I agree, there is too much difference to be able to explain with 2 days vs. 5 days averages. The NSIDC shows a very marked and rapid drop, the JAXA doesn't.

NSIDC has extent dropping by almost 300.000 km2 since August 31st, Jaxa has just about 80.000. That's a vast difference over a 5 day period!

NSIDC is at 4.235 on the 5th, JAXA on 4.16 on the same day. So in spite of dropping by 220.000 km2 more, NSIDC is still 75.000 km2 above JAXA (I know that the two rarely meet, but I'm just trying to figure out what is going on here!)

because a thing is eloquently expressed it should not be taken to be as necessarily true
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2383 on: September 07, 2019, 01:36:40 PM »
Despite this day's extent gain, very high SSTs and bottom melt could still provide the conditions for a later date of minimum as well as a slow refreeze (if surface weather conditions are at least not unfavourable). However, unfavourable seems to be the flavour of the moment.
Perhaps it's time to go back to a comparison with 2018 on the chart
When the freezing season thread opens I will be giving the spreadsheet it's 6 monthly overhaul.
"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: 2019 sea ice area and extent data
« Reply #2384 on: September 07, 2019, 03:19:35 PM »
NSIDC Total Area as at 6 September 2019 (5 day trailing average)  2,921,298  km2

End of season wobbles rule, OK?....
On this day the 5 day trailing average AREA increased by modest 11k, the day before decreased by a measly 6k, .
One-day NSIDC EXTENT gain 49, JAXA extent gain 0.4 k

                        
Total Area         
 2,921,298    km2      
-196,479    km2   <   2010's average.
-426,618    km2   <   2018
-1,146,959    km2   <   2000's average.
         
Total Area Change    11    k   gain
Peripheral Seas    3    k   gain
Central Seas__    8    k   gain
Other Seas___    0    k   gain
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -0    k   loss
Greenland____    3    k   gain
Barents ______   -0    k   loss
         
CAB Seas         
Beaufort_____    12    k   gain
CAA_________   -2    k   loss
East Siberian__   -2    k   loss
Central Arctic_   -0    k   loss
         
Kara_________    1    k   gain
Laptev_______   -1    k   loss
Chukchi______    0    k   gain
         
Other Seas         
Okhotsk______    0    k   gain
St Lawrence___    -    k   loss
Hudson Bay___    0    k   gain
- Area GAIN 6 k, 30 k different from the 2010's average area loss of 19 k on this day,
- Total area 3rd Lowest, 433 k MORE than 2016, and 566 k MORE than 2012.
________________________________________________________________________
Outlook
We are now well into the last few days of reducing and very variable daily area loss that that will slide to zero by around mid-September (or a bit later?).
"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: 2019 sea ice area and extent data
« Reply #2385 on: September 07, 2019, 03:27:57 PM »
Lord M Vader twitching about opening the freezing thread.

The Area Plume says - hold on, most previous years say more area losses.

patiencia, calma, homem.
"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)

weatherdude88

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Re: 2019 sea ice area and extent data
« Reply #2386 on: September 07, 2019, 05:29:25 PM »
The Area Plume says - hold on, most previous years say more area losses.

The single daily NSIDC sea ice area value for 9.6 is 3,012,376 square kilometers (pole hole adjustment).
 
This is significant gain of 52,449 square kilometers from the previous day. We are now 111,973 square kilometers above the 9.4 NSIDC sea ice area minimum value.

The 2019 NSIDC sea ice area melting season has concluded. We are now in the freezing season. Historically, we would need anomalous sea ice area losses to extend the sea ice area melting season.

If you remove 9.4 from the daily NSIDC area data set, 8.24 would have been the lowest area value for the 2019 melting season.

On this day the 5 day trailing average AREA increased by modest 11k, the day before decreased

Even with the 3 oldest days showing area losses, the 5 day average increased by "11k".  There is going to be a significant increases in the 5 day trailing average starting tomorrow, as the older days fall off.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2387 on: September 07, 2019, 05:35:57 PM »
"The 2019 NSIDC sea ice area melting season has concluded."

I used to write  such 100% definite opinions. Oftimes I ended up eating crow. Now I would write

"The 2019 NSIDC sea ice area melting season has most likely concluded."
"Para a Causa do Povo a Luta Continua!"
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Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #2388 on: September 08, 2019, 04:39:43 AM »
NSIDC daily extent

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #2389 on: September 08, 2019, 05:43:59 AM »
September 7th, 2019:
     4,168,525 km2, a drop of -7,562 km2.
     2019 is 3rd lowest on record.
     (2007, 2012 & 2016 highlighted).
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: 2019 sea ice area and extent data
« Reply #2390 on: September 08, 2019, 11:42:43 AM »
JAXA ARCTIC SEA ICE EXTENT :- 4,168,525 km2(September 7, 2019)

Below average extent loss of 7.5k. A minimum of less than 4 million km2 looks an long way away. 
- Extent is 3rd lowest in the satellite record,
- Extent is 856 k greater than 2012, 151 k greater than 2016. 2016 is at its minimum on this day.
- Extent loss on this day 8 k , 18 kless than the average loss on this day of 26 k.
- Extent loss from maximum 10,103 k, 320 k (3.3%) greater than the average of 9,782 k loss from maximum by this day,
- On average 99.0% of the melting season done, with 6 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt (0.10 million km) would give a minimum of 4.07 million km2, equal 3rd lowest (with 2007) in the satellite record, 0.89 million km2 above the 2012 low of 3.18 million km2 and 0.05 millon km2 greater than the 2nd lowest in 2016 of 4.02 million km2.

Ice Melt Outlook The peak days of daily melt are past. From now to minimum, on average daily extent loss will gradually but erratically reduce until the minimum. 

Each day now consumes 16 % of the average time available for further extent loss. However, in the the last 10 years there were as few as just 0 days or as many as 15 days of extent losses to come.

In only two of the last 10 previous years (2010 and 2018) was remaining melt enough to bring 2019 to a minimum below 4 million km2.

Nevertheless, very high SSTs and bottom melt could still provide the conditions for a later date of minimum as well as a slow refreeze (if surface weather conditions are at least not unfavourable). However, unfavourable seems to be the flavour of the moment.
____________________________________________________________
"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: 2019 sea ice area and extent data
« Reply #2391 on: September 08, 2019, 03:32:51 PM »
NSIDC Total Area as at 7 September 2019 (5 day trailing average)  2,934,397  km2

On this day the 5 day trailing average AREA increased by a modest 13k, the day before a gain of  11k.
One-day NSIDC EXTENT loss 9k, JAXA extent loss 7.5 k

                        
Total Area         
 2,934,397    km2      
-167,386    km2   <   2010's average.
-408,701    km2   <   2018
-1,125,654    km2   <   2000's average.
         
Total Area Change    13    k   gain
Peripheral Seas    3    k   gain
Central Seas__    10    k   gain
Other Seas___   -0    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -0    k   loss
Greenland____    4    k   gain
Barents ______   -0    k   loss
         
CAB Seas         
Beaufort_____    4    k   gain
CAA_________    2    k   gain
East Siberian__   -2    k   loss
Central Arctic_    5    k   gain
         
Kara_________    0    k   gain
Laptev_______   -0    k   loss
Chukchi______    0    k   gain
         
Other Seas         
Okhotsk______   -0    k   loss
St Lawrence___    -    k   loss
Hudson Bay___   -0    k   loss
- Area GAIN 13 k, 29 k different from the 2010's average area loss of 16 k on this day,
- Total area 3rd Lowest, 475 k MORE than 2016, and 593 k MORE than 2012.
________________________________________________________________________
Outlook
We are now well into the last few days of reducing and very variable daily area loss that that will slide to zero by around mid-September (or a bit later?).
"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: 2019 sea ice area and extent data
« Reply #2392 on: September 08, 2019, 03:39:44 PM »
Has the area minimum for 2019 been and gone?

Here is the plume of projections.
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Stephan

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Re: 2019 sea ice area and extent data
« Reply #2393 on: September 08, 2019, 05:06:59 PM »
Analysis of the individual seas "relative area wise".
This is probably the last analysis of this type for this melting season. The days of 5-10% daily area losses are gone. One sea has already gained sea ice between Aug 21 and Sep 07.
Losses between 38% and 26% were observed in ESS, Laptev and Grønland Seas
CAA lost around 16% of its ice, whereas CAB remained almost constant.
The Beaufort Sea gained 21%, most probably not by early refreezing but by movement of ice from CAB (and maybe a little from CAA)

Seas with no ice were not analysed.
It is too late just to be concerned about Climate Change

Steven

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Re: 2019 sea ice area and extent data
« Reply #2394 on: September 08, 2019, 07:30:24 PM »
NSIDC daily area is now 2.97 million km2, which is 5th lowest for the date (slightly above 2007 and 2011):



The year-to-date minimum for 2019 so far is 2.87 million km2 on 4 September 2019.

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #2395 on: September 09, 2019, 05:45:13 AM »
September 8th, 2019:
     4,163,470 km2, a drop of -5,055 km2.
     2019 is 3rd lowest on record.
     (2007, 2012 & 2016 highlighted).
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: 2019 sea ice area and extent data
« Reply #2396 on: September 09, 2019, 11:18:54 AM »
NSIDC daily extent

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2397 on: September 09, 2019, 02:13:02 PM »
JAXA ARCTIC SEA ICE EXTENT :- 4,163,470 km2(September 8, 2019)

A minimal extent loss of 5k. Extent is 5k above the current minimum on 4th September. What a tease. 
- Extent is 3rd lowest in the satellite record,
- Extent is 863 k greater than 2012, 139 k greater than 2016. 2016 extent is now increasing.
- Extent loss on this day 5 k , 14 k less than the average loss on this day of 19 k.
- Extent loss from maximum 10,108 k, 307 k (3.1%) greater than the average of 9,801 k loss from maximum by this day,
- On average 99.2% of the melting season done, with 5 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt (0.08 million km) would give a minimum of 4.08 million km2, 4th lowest in the satellite record, 0.91 million km2 above the 2012 low of 3.18 million km2 and 0.06  greater than 2016, 0.01 greater than 2007.

However, the uncertainty is such that I am posting the plume of projections instead of what is really a meaningless projection table.

Ice Melt Outlook ??

Each day now consumes 20 % of the average time available for further extent loss. However, in the the last 10 years there were as few as just -1 days or as many as 14 days of extent losses to come.

In none of the last 10 previous years was remaining extent loss enough to bring 2019 to a minimum below 4 million km2.

Nevertheless, very high SSTs and bottom melt could still provide the conditions for a later date of minimum as well as a slow refreeze (if surface weather conditions are at least not unfavourable). However, unfavourable seems to be the flavour of the moment.
____________________________________________________________
"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: 2019 sea ice area and extent data
« Reply #2398 on: September 09, 2019, 03:20:24 PM »
NSIDC Total Area as at 8 September 2019 (5 day trailing average)  2,936,982   km2

On this day the 5 day trailing average AREA increased by a minimal 3k
One-day NSIDC EXTENT loss 16k, JAXA extent loss 5 k

                        
Total Area         
 2,936,982    km2      
-149,639    km2   <   2010's average.
-383,609    km2   <   2018
-1,117,703    km2   <   2000's average.
         
Total Area Change    3    k   gain
Peripheral Seas    6    k   gain
Central Seas__   -3    k   loss
Other Seas___   -0    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -1    k   loss
Greenland____    7    k   gain
Barents ______    0    k   gain
         
CAB Seas         
Beaufort_____   -3    k   loss
CAA_________    4    k   gain
East Siberian__   -2    k   loss
Central Arctic_   -3    k   loss
         
Kara_________    1    k   gain
Laptev_______   -0    k   loss
Chukchi______   -0    k   loss
         
Other Seas         
Okhotsk______   -0    k   loss
St Lawrence___    -    k   loss
Hudson Bay___   -0    k   loss
- Area GAIN 3 k, 19 k different from the 2010's average area loss of 16 k on this day,
- Total area 3rd Lowest, 488 k MORE than 2016, and 608 k MORE than 2012.
- Area is 25k more than the current minimum on 3rd September.
________________________________________________________________________
Outlook
We are now well into the last few days of reducing and very variable daily area loss that that will slide to zero by around mid-September (or a bit later?, or a bit earlier?).
"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: 2019 sea ice area and extent data
« Reply #2399 on: September 09, 2019, 03:21:43 PM »
NSIDC daily extent