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Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #2050 on: August 10, 2019, 05:44:03 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

August 9th, 2019:
     5,239,109 km2, almost a century drop of -95,164 km2.
     2019 is 2nd lowest on record.
     (2012 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 #2051 on: August 10, 2019, 06:19:52 AM »
JAXA ARCTIC EXTENT :- 5,239,109 km2(August 9, 2019)

JAXA daily extent loss on this day was well above average.

- Extent is 2nd lowest in the satellite record (after 49 days at lowest this year),
- extent is 203 k above 2012, 417 k below 2016.
- Extent loss on this day 95 k, 18 k more than the average loss on this day of 77 k.
- Extent loss from maximum 9.032 k, 614 k (7.3%) greater than the average of 8,418 k loss from maximum by this day,
- On average 85.2% of the melting season done, with 35 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.78 million km2, 2nd lowest in the satellite record, 0.60 million km2 above the 2012 low of 3.18 million km2 and 0.24 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 reduce until the minimum. 

GFS 5 day weather outlook Almost no change
- Central Siberia looks very warm, with the warmth spreading to the far east and Alaska
- A band of cold weather from Western Canada to the south of Hudson Bay,
- Northern GreenlandBaffin Bay and the CAA still warm - with occasional rain on the CAA. 
- Southern Greenland staying gradually cooling to below average temperatures.
- And once again it looks like there will be not much export of ice down the Fram into the Greenland Sea.
- A cyclone centered over Novaya Zemla bringing southerly winds from a very warm Siberia may push warmth and even rain across the Arctic Ocean. and then from the central arctic towards the Barents.
____________________________________________________________
To be a record low, remaining melt needs to be 40% above the average. No year has ever done this.

JAXA daily loss is staying strong, in contrast with the 9 Aug NSIDC data.
Was the NSIDC data on that day an aberration ?
Will they have to send someone up there to clean the lens on NSIDC's satellite?
"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 #2052 on: August 10, 2019, 03:50:55 PM »
NSIDC Total Area as at 9 August 2019 (5 day trailing average)  3,570,381 km2

The 7 day turnaround has stopped.
On 8 August area loss collapsed.
On this day area loss collapsed even more.
                        
Total Area         
 3,570,381    km2      
-463,667    km2   <   2010's average.
-468,455    km2   <   2018
-1,289,749    km2   <   2000's average.
         
Total Area Change   -13    k   loss
Peripheral Seas   -2    k   loss
Central Seas__   -12    k   loss
Other Seas___    1    k   gain
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -0    k   loss
Greenland____   -1    k   loss
Barents ______   -0    k   loss
         
CAB Seas         
Beaufort_____   -3    k   loss
CAA_________   -6    k   loss
East Siberian__   -22    k   loss
Central Arctic_    22    k   gain
         
Kara_________   -1    k   loss
Laptev_______    0    k   gain
Chukchi______   -3    k   loss
         
Other Seas         
Okhotsk______   -0    k   loss
St Lawrence___    -    k   loss
Hudson Bay___    1    k   gain
- Area loss 13 k, 39 k LESS than the 2010's average area loss of 52 k on this day.
- Total area 2nd Lowest, 102 k LESS than 2016, and 327 k MORE than 2012.

Of note is:
- Most of the seven seas of the High Arctic are losing seas ice area at well below average daily rates or even gaining area.
- The Chukchi & Beaufort seas area loss have slowed to a crawl,
- The ESS is still losing area at a good clip,,
- The CAA should still be really warm all this week again - and some rain. Also high daily melt.
- No or little Fram export - but Greenland area loss slowed.
- The CAB gained area strongly and thus is even more above the 2010's average .

Outlook
We are now in the period of reducing daily area loss that that will slide to zero by mid-September.
On these last 2 days area extremely below average, much less than 2016 and much less than 2012.
________________________________________________________________________
Area continues 'twixt 2012 and 2016 but this so slow loss if continued could change things quickly.
BUT...
NSIDC daily extent loss was a  healthy 131k on this day.
JAXA extent loss was well above average,
GFS weather forecast suggests a change may be on its way to give area loss a fillip.
Maybe this collapse in loss is temporary, maybe not.
"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 #2053 on: August 10, 2019, 04:07:22 PM »
This end of season is getting quite strange.

Extent loss remains strong.
Area loss very weak.
so Dispersion is reduced, i.e. compaction is increased,

and the remaining ice congregates North of 80 in the CAB?

(while the ESS sea ice disintegrates at the fastest rate since 2007)
"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 #2054 on: August 10, 2019, 04:36:12 PM »
The area loss mid August is not unprecendented. All three other individual years in the graph (2012, 2016, and - less pronounced - 2018) had some kind of slowdown mid August and an acceleration later on. The melt season is not over, it is only slowing down.
It is too late just to be concerned about Climate Change

Patrice

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Re: 2019 sea ice area and extent data
« Reply #2055 on: August 10, 2019, 05:42:42 PM »
@gerontocrat: Nice representation of dispersion, but small wish: Is there a way you include 2007 in your dispersion graphs ?

Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #2056 on: August 10, 2019, 09:18:50 PM »
NSIDC daily extent

Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #2057 on: August 10, 2019, 09:23:43 PM »
An NSIDC extent change of just -141 tomorrow would catch up with 2012.

Sterks

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Re: 2019 sea ice area and extent data
« Reply #2058 on: August 10, 2019, 09:39:04 PM »
The weather seems favorable to keeping century drops for the next 5 days. Cyclone moving to Beaufort sea and anticyclone dominating in the Asian side and CAB.

Killian

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Re: 2019 sea ice area and extent data
« Reply #2059 on: August 11, 2019, 06:01:42 AM »
An NSIDC extent change of just -141 tomorrow would catch up with 2012.

Does tomorrow mean for the 10th or the 11th? For the 10th should be 5.30M+/-30k (87%; +/-10k 52%. Big moves tend to push the error level up for a few days, but 95% chance it will be within 50k, or 5.25~5.35.)

bbr2314

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Re: 2019 sea ice area and extent data
« Reply #2060 on: August 11, 2019, 06:11:16 AM »
JAXA at 5.11 -130Kish though obvs Juan's post will be better  ;D

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #2061 on: August 11, 2019, 06:18:10 AM »
JAXA at 5.11 -130Kish though obvs Juan's post will be better  ;D
Thank you for your post.  :)
I am traveling with my family…  ;)
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

August 10th, 2019:
     5,106,603 km2, a century drop of -132,506 km2.
     2019 is 2nd lowest on record.
     (2012 highlighted).
« Last Edit: August 11, 2019, 06:39:59 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.

DrTskoul

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Re: 2019 sea ice area and extent data
« Reply #2062 on: August 11, 2019, 06:46:41 AM »
What a curvature... things are getting interesting!!

jdallen

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Re: 2019 sea ice area and extent data
« Reply #2063 on: August 11, 2019, 08:26:23 AM »
NSIDC Total Area as at 9 August 2019 (5 day trailing average)  3,570,381 km2

The 7 day turnaround has stopped.
On 8 August area loss collapsed.
On this day area loss collapsed even more.

Fascinating.  The collapse is running counter to everything we tend to expect from the current conditions. Consider for example the SST map from Climate Reanalyzer below. Consider also the current circulation and weather conditions.  What is happening is completely counter-intuitive.  It suggests we are missing some major factor.
This space for Rent.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2064 on: August 11, 2019, 09:28:33 AM »
JAXA ARCTIC EXTENT :- 5,106,603 km2(August 10, 2019)

JAXA daily extent loss on this day was again well above average, accelerating to a well above century break.

- Extent is 2nd lowest in the satellite record (after 49 days at lowest this year),
- extent is 163 k above 2012, 474 k below 2016.
- Extent loss on this day 133 k, 60 k more than the average loss on this day of 73 k.
- Extent loss from maximum 9.165 k, 674 k (7.9%) greater than the average of 8,490 k loss from maximum by this day,
- On average 85.9% of the melting season done, with 34 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.72 million km2, 2nd lowest in the satellite record, 0.54 million km2 above the 2012 low of 3.18 million km2 and 0.30 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 reduce until the minimum. 

GFS 5 day weather outlook Again, almost no change
- Central Siberia looks very warm, with the warmth spread to the far east and Alaska
- A band of cold weather from Western Canada to the south of Hudson Bay,
- Northern Greenland, Baffin Bay and the CAA still warm - with occasional rain on the CAA. 
- Southern Greenland staying gradually cooling to well below average temperatures.
- And once again it looks like there will be not much export of ice down the Fram into the Greenland Sea.
- A cyclone centered over Novaya Zemla bringing southerly winds from a very warm Siberia may push warmth and even rain across the Arctic Ocean. and then winds from the central arctic towards the Barents.
____________________________________________________________
To be a record low, remaining melt needs to be 40% above the average. No year has ever done this from this late date in the season - not even 2012.

The average projection, being less than 3.75, is down one bin.

JAXA daily loss is staying strong, in contrast with the 9 & 10 Aug NSIDC data.
Was the NSIDC data on those days an aberration ?
Have they sent someone up there to clean the lens on NSIDC's satellite 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)

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2065 on: August 11, 2019, 09:40:12 AM »
And to end the week...

Attached is the plume of projections of the minimum from the last 10 years remaining melt. All but one (2017) project a minimum below 4 million km2.

Also attached is the current position of 2019 compared with minima from previous years. i.e. if the 10 August extent was the minimum for 2019, 2019 would be 13th lowest in the satellite record.
"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)

Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #2066 on: August 11, 2019, 01:08:54 PM »
NSIDC Total Area as at 9 August 2019 (5 day trailing average)  3,570,381 km2

The 7 day turnaround has stopped.
On 8 August area loss collapsed.
On this day area loss collapsed even more.

Fascinating.  The collapse is running counter to everything we tend to expect from the current conditions. Consider for example the SST map from Climate Reanalyzer below. Consider also the current circulation and weather conditions.  What is happening is completely counter-intuitive.  It suggests we are missing some major factor.

This melt season is riveting. I think we have still not fully understood what a dramatically cloudier, wetter Arctic will behave like. Your observations about the current circulation and weather conditions is the right question to ask. I have none of the answers.

With all of the early open water and heat uptake, combined with the new cloudier Arctic holding that heat in, it would not surprise me if we have ridiculously warm autumn temps and a very slow refreeze.

Ice Shieldz

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Re: 2019 sea ice area and extent data
« Reply #2067 on: August 11, 2019, 01:26:30 PM »
Indeed SH. As a point of clarity to your post, it’s mostly because we didn’t have a cloudy Arctic during the melt season that enabled the melting of ice and the heat uptake into open waters.

DrTskoul

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Re: 2019 sea ice area and extent data
« Reply #2068 on: August 11, 2019, 02:36:52 PM »
NSIDC Total Area as at 9 August 2019 (5 day trailing average)  3,570,381 km2

The 7 day turnaround has stopped.
On 8 August area loss collapsed.
On this day area loss collapsed even more.

Fascinating.  The collapse is running counter to everything we tend to expect from the current conditions. Consider for example the SST map from Climate Reanalyzer below. Consider also the current circulation and weather conditions.  What is happening is completely counter-intuitive.  It suggests we are missing some major factor.

 Bottom melt?

Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #2069 on: August 11, 2019, 02:39:55 PM »
Indeed SH. As a point of clarity to your post, it’s mostly because we didn’t have a cloudy Arctic during the melt season that enabled the melting of ice and the heat uptake into open waters.

Yes. I didn't mean to imply that a more humid, cloudy Arctic always meant bad conditions for the ice. It's just that we need to get a handle on this to understand what is happening.

I do think that very warm Arctic autumns and early winters are the new normal as clouds inhibit the release of heat into space. The effect is less pronounced later in the winter as the Arctic completely ices over.

Sterks

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Re: 2019 sea ice area and extent data
« Reply #2070 on: August 11, 2019, 03:21:53 PM »
NSIDC Total Area as at 9 August 2019 (5 day trailing average)  3,570,381 km2

The 7 day turnaround has stopped.
On 8 August area loss collapsed.
On this day area loss collapsed even more.

Fascinating.  The collapse is running counter to everything we tend to expect from the current conditions. Consider for example the SST map from Climate Reanalyzer below. Consider also the current circulation and weather conditions.  What is happening is completely counter-intuitive.  It suggests we are missing some major factor.

This melt season is riveting. I think we have still not fully understood what a dramatically cloudier, wetter Arctic will behave like. Your observations about the current circulation and weather conditions is the right question to ask. I have none of the answers.

With all of the early open water and heat uptake, combined with the new cloudier Arctic holding that heat in, it would not surprise me if we have ridiculously warm autumn temps and a very slow refreeze.
With all due respect, there's nothing counter intuitive between the current weather and the extent drop.
FooW explained it very well a few days ago: warmth and compaction over Laptev and ESS, a cyclone messing up Beaufort, and continued heat in CAA

Sterks

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Re: 2019 sea ice area and extent data
« Reply #2071 on: August 11, 2019, 03:30:22 PM »
NSIDC Total Area as at 9 August 2019 (5 day trailing average)  3,570,381 km2

The 7 day turnaround has stopped.
On 8 August area loss collapsed.
On this day area loss collapsed even more.

Fascinating.  The collapse is running counter to everything we tend to expect from the current conditions. Consider for example the SST map from Climate Reanalyzer below. Consider also the current circulation and weather conditions.  What is happening is completely counter-intuitive.  It suggests we are missing some major factor.
You picked not the relevant chart. Past days at ESS and the Pacific side in general were really cold with massive surface refreezing, but winds have already shifted.

Alphabet Hotel

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Re: 2019 sea ice area and extent data
« Reply #2072 on: August 11, 2019, 03:37:04 PM »
NSIDC daily extent

Steven

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Re: 2019 sea ice area and extent data
« Reply #2073 on: August 11, 2019, 03:41:51 PM »
NSIDC daily area is currently second lowest for the date:



Anomalies:

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2074 on: August 11, 2019, 03:51:34 PM »
NSIDC Total Area as at 10 August 2019 (5 day trailing average)  3,534,314 km2

The 7 day turnaround has stopped.
On 8 August area loss collapsed.
On 9 August area loss collapsed even more.
And on this day area loss increased but still low
                        
Total Area         
 3,534,314    km2      
-452,033    km2   <   2010's average.
-449,267    km2   <   2018
-1,277,441    km2   <   2000's average.
         
Total Area Change   -36    k   loss
Peripheral Seas    0    k   gain
Central Seas__   -36    k   loss
Other Seas___   -0    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -0    k   loss
Greenland____    1    k   gain
Barents ______   -0    k   loss
         
CAB Seas         
Beaufort_____   -6    k   loss
CAA_________   -3    k   loss
East Siberian__   -18    k   loss
Central Arctic_    1    k   gain
         
Kara_________   -1    k   loss
Laptev_______   -7    k   loss
Chukchi______   -2    k   loss
         
Other Seas         
Okhotsk______   -0    k   loss
St Lawrence___    -    k   loss
Hudson Bay___   -0    k   loss
- Area loss 36 k, 20 k LESS than the 2010's average area loss of 56 k on this day.
- Total area 2nd Lowest, 98 k LESS than 2016, and 365 k MORE than 2012.

Outlook
We are now in the period of reducing daily area loss that that will slide to zero by mid-September.
On these last 3 days area loss below average, much less than 2016 and much less than 2012.
________________________________________________________________________
Area continues 'twixt 2012 and 2016 but this  slow loss if continued could change things quickly.
BUT...
NSIDC daily extent loss was a  healthy 166k on this day.
JAXA extent loss was well above average,
GFS weather forecast suggests a change may be in process to give area loss a fillip.
Maybe this slowdown in loss is temporary, maybe not.
"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 #2075 on: August 11, 2019, 03:53:40 PM »
By special request here is the dispersion graph with 2007 added.
Compaction increases.
"Para a Causa do Povo a Luta Continua!"
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Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #2076 on: August 11, 2019, 04:35:30 PM »
You picked not the relevant chart. Past days at ESS and the Pacific side in general were really cold with massive surface refreezing, but winds have already shifted.

Any evidence of this massive surface refreezing in the ESS or the Pacific side in general would be appreciated.

Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #2077 on: August 11, 2019, 04:42:05 PM »
Area charts also suggest the ESS is toast.

Record early or burnt toast if you will.

Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #2078 on: August 11, 2019, 04:56:24 PM »
By special request here is the dispersion graph with 2007 added.
Compaction increases.

Looking at how dispersed the ice was in 2012 at this time as compared to 2019, what does it suggest about our little horse race to the minimum?

DrTskoul

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Re: 2019 sea ice area and extent data
« Reply #2079 on: August 11, 2019, 05:10:37 PM »
By special request here is the dispersion graph with 2007 added.
Compaction increases.

Looking at how dispersed the ice was in 2012 at this time as compared to 2019, what does it suggest about our little horse race to the minimum?
2nd....

Stephan

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Re: 2019 sea ice area and extent data
« Reply #2080 on: August 11, 2019, 05:24:24 PM »
Evaluation of the area loss in the different seas "relative area wise" July 27-Aug 10, 2019:
Losses between 54 and 63% occurred in Chukchi, ESS, Hudson* and Kara.
Several seas lost 34-40% of their ice area: CAA, Baffin*, Barents*, Grønland, and Beaufort.
The loss in Laptev was lower (20%).
A very small loss happened in the largest sea (CAB), only 5 %.

* last evaluation for this melting season as there is only very little ice left.
Seas with no ice were not analysed.
It is too late just to be concerned about Climate Change

Sterks

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Re: 2019 sea ice area and extent data
« Reply #2081 on: August 11, 2019, 05:34:22 PM »
You picked not the relevant chart. Past days at ESS and the Pacific side in general were really cold with massive surface refreezing, but winds have already shifted.

Any evidence of this massive surface refreezing in the ESS or the Pacific side in general would be appreciated.
I meant CAB sector north of ESS

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2082 on: August 11, 2019, 06:36:14 PM »
Because its been about a week time to give the graphs an airing.

Chukchi - an impressive melt this year, early and strong. Not far to go.

Baffin - also impressive early and stronger melt. Pretty much done.

CAA - after a late start area is now well below the 2010s average.

Hudson - finished melt a bit earlier than average but of no consequence.
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2083 on: August 11, 2019, 07:03:46 PM »
Greenland Sea Area - much more an indicator of Fram Strait export than the weather. Above and below 2010's average all season.

Barents Sea - a complete contrast with 2012 and 2016. Extremely slow melt, due to persistent sea ice drift from the Russian side of the CAB.

Kara Sea - 2019 started late but caught up. Melt has probably finished, as for some reason the Kara never completely melts out. Note also how back in the 1980's the melt profile was a simple V shape. Now that profile is a much wider U shape. Also freeze is later, and in recent years winter sea ice looks much more vulnerable.

Laptev Sea - Started early and fast and has stayed that way. Over the years has started to show the same U-shape profile as the Kara, and somewhat less stable winter ice.
"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: 2019 sea ice area and extent data
« Reply #2084 on: August 11, 2019, 07:20:03 PM »
Beaufort Sea started melt early and strong, but after a couple of stalls no longer looks like a record-breaker this year. Minimum likely to be well below 2010's average.

The East Siberian Sea (ESS) shows perhaps the most dramatic reduction in summer ice area of all the sea in the Arctic, and this year is no exception as regards timing and speed of area loss. At the moment with 2012 as lowest in the satellite record and little reason to suppose the end result will be different.

The Central Arctic Sea was late in starting melt and is late now, somewhat behind the 2010's average. Looking at the 40 year record, one can see the very shallow and small summer sea ice looses in the 1980's developing into the deep but very short-term losses in the 2010's, making a very deep V--shaped profile. It looks like a long time before losses are large enough and long-term enough to start developing the U-profile of a sea losing its icy desert status.

And that's me lot. The Bering, Okhotsk & Lawrence were finished some time ago.
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petm

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Re: 2019 sea ice area and extent data
« Reply #2085 on: August 11, 2019, 07:26:48 PM »
Beaufort Sea started melt early and strong, but after a couple of stalls no longer looks like a record-breaker this year.

Not stalls, advection, and rapid melt continues unabated.

binntho

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Re: 2019 sea ice area and extent data
« Reply #2086 on: August 11, 2019, 07:32:12 PM »
You are very right to point out the shapes of those graphs, Gero - they tell their own very important story.
because a thing is eloquently expressed it should not be taken to be as necessarily true
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petm

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Re: 2019 sea ice area and extent data
« Reply #2087 on: August 11, 2019, 07:48:45 PM »
Perhaps I'm being too pendantic, objecting to 'stall', which to me implies mechanism rather than simply curve shape. Anyways, I now will continue to not comment on this thread. Thanks for all the graphs and tables.

AndyW

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Re: 2019 sea ice area and extent data
« Reply #2088 on: August 11, 2019, 07:51:44 PM »
NSIDC Total Area as at 9 August 2019 (5 day trailing average)  3,570,381 km2

The 7 day turnaround has stopped.
On 8 August area loss collapsed.
On this day area loss collapsed even more.

Fascinating.  The collapse is running counter to everything we tend to expect from the current conditions. Consider for example the SST map from Climate Reanalyzer below. Consider also the current circulation and weather conditions.  What is happening is completely counter-intuitive.  It suggests we are missing some major factor.

This melt season is riveting. I think we have still not fully understood what a dramatically cloudier, wetter Arctic will behave like. Your observations about the current circulation and weather conditions is the right question to ask. I have none of the answers.

With all of the early open water and heat uptake, combined with the new cloudier Arctic holding that heat in, it would not surprise me if we have ridiculously warm autumn temps and a very slow refreeze.

Both 2007 and 2012 had very steep refreezes come mid October on the extent graphs. Statistically speaking you could argue 2019, if very low, will follow the same path, just because it is getting back up to to the norm of ice extent with Autumn temperatures at those high latitudes. Just like 2007 and 2012.

A corollary would be an extreme sea ice extent after winter would melt out at a greater rate come summer so a huge drop would be seen. Of course we have not had that recently.

Rate of increase after the summer minimum is not really any thing to go by IMO. Neither a rate of spring melt after a huge winter extent.


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Re: 2019 sea ice area and extent data
« Reply #2089 on: August 11, 2019, 08:01:52 PM »
You picked not the relevant chart. Past days at ESS and the Pacific side in general were really cold with massive surface refreezing, but winds have already shifted.

Any evidence of this massive surface refreezing in the ESS or the Pacific side in general would be appreciated.
Yes, your pattern recognition ability to observe the increase in concentration in the pacific edge between the 4th and the 10th of August.

bbr2314

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Re: 2019 sea ice area and extent data
« Reply #2090 on: August 11, 2019, 08:06:06 PM »
You picked not the relevant chart. Past days at ESS and the Pacific side in general were really cold with massive surface refreezing, but winds have already shifted.

Any evidence of this massive surface refreezing in the ESS or the Pacific side in general would be appreciated.
Yes, your pattern recognition ability to observe the increase in concentration in the pacific edge between the 4th and the 10th of August.
I think you are being rude and you are also incorrect, there was no increase in concentration, but there has been an increase in CLOUDS which creates the artifact you incorrectly attribute to refreeze.

binntho

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Re: 2019 sea ice area and extent data
« Reply #2091 on: August 11, 2019, 08:08:58 PM »
You picked not the relevant chart. Past days at ESS and the Pacific side in general were really cold with massive surface refreezing, but winds have already shifted.

Any evidence of this massive surface refreezing in the ESS or the Pacific side in general would be appreciated.
Yes, your pattern recognition ability to observe the increase in concentration in the pacific edge between the 4th and the 10th of August.
I don't see how there could have been any refreeze at all anywhere in the Arctic at this time. The temps simply do not allow for it.
because a thing is eloquently expressed it should not be taken to be as necessarily true
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oren

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Re: 2019 sea ice area and extent data
« Reply #2092 on: August 11, 2019, 08:10:45 PM »
I'd be extremely surprised if there was any refreeze this early. This requires sustained low temps, often initial refreeze occurs at -10C. I am quite certain this was an AMSR2 artifact.

petm

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Re: 2019 sea ice area and extent data
« Reply #2093 on: August 11, 2019, 08:21:27 PM »
Shouldn't this discussion be on the main melting thread?

There is a heat wave going on in the Laptev sector -- do you really think it suddenly froze up in 1 day? If you're not sure, you could always look at now abundantly available satellite imagery...

As has been said repeatedly, single day values of the Bremen maps are almost meaningless, mostly due to cloud artifacts. Clouds generally show up at 100% concentration (purple), move fast (if you look at multiple days), and are shaped like... clouds (big curves, etc.).

If you want to see it visually, I have posted numerous side-by-side images and animations comparing the originals to medians and minimums. Attached are today's 5-day minimum and median. In my opinion, the minimum is probably closest to reality at this time of year.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #2094 on: August 11, 2019, 08:25:19 PM »
You picked not the relevant chart. Past days at ESS and the Pacific side in general were really cold with massive surface refreezing, but winds have already shifted.

Any evidence of this massive surface refreezing in the ESS or the Pacific side in general would be appreciated.
Yes, your pattern recognition ability to observe the increase in concentration in the pacific edge between the 4th and the 10th of August.
I must remember that a gif of just 2 days, several days apart, played quite slowly, gives so much more to my tired old eyes than the gifs of many days running swiftly together. It's the enhanced contrast.

and...
- is that a fairly large Artefact twixt Revolution Island and the Russian shore at 90 East?
- perhaps an even chance for the Parry Channel to open before the end of the month?
- will there just be a great lump of solid ice North of 80 (frayed a bit at the edges) and almost nothing anywhere else by mid-September? If so, still a chance of a record low extent?
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werther

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Re: 2019 sea ice area and extent data
« Reply #2095 on: August 11, 2019, 08:42:56 PM »
Try Daily Composites NCEP/NCAR...no 'really cold' weather anywhere in the Arctic 1-9 august. In fact, temp anomaly is worse than '12.
Be sure to compare sea surface temps northern hemisphere. '12 to '19. Shocking.

jdallen

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Re: 2019 sea ice area and extent data
« Reply #2096 on: August 11, 2019, 09:24:11 PM »
>>>> moved to melt season thread
« Last Edit: August 11, 2019, 09:31:17 PM by jdallen »
This space for Rent.

Sterks

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Re: 2019 sea ice area and extent data
« Reply #2097 on: August 11, 2019, 09:57:27 PM »
Try Daily Composites NCEP/NCAR...no 'really cold' weather anywhere in the Arctic 1-9 august. In fact, temp anomaly is worse than '12.
Be sure to compare sea surface temps northern hemisphere. '12 to '19. Shocking.
Are you comparing this to 2012, during or right after the GAC??? Which left atmosphere pretty cold as any moderate storm???
« Last Edit: August 11, 2019, 10:29:51 PM by Sterks »

philopek

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Re: 2019 sea ice area and extent data
« Reply #2098 on: August 11, 2019, 10:25:31 PM »
Fascinating.  The collapse is running counter to everything we tend to expect from the current conditions. Consider for example the SST map from Climate Reanalyzer below. Consider also the current circulation and weather conditions.  What is happening is completely counter-intuitive.  It suggests we are missing some major factor.

I was pondering over this due to the UNI-BREMEN maps where concentration is kind of blinking in and out and had the idea that:

It could be that relatively warm, steady and not so week winds in case of low angle insolation, would kind of dry the surface while at the same time when it looks higher concentrated due to less wetness, melting is in overdrive.

Since my language skills don't allow the describe it better, i'd compare this what i mean with foehn winds in the alps, only that they, event though they are dry, warm and of certain force, are not katabatic in this case.

I will happily stand to be correct if this is non-sense, just explain it well and in a non-condescending manner. ( precaution haha... )

EDIT: Not to forget cloud cover as mentione above, so perhaps my idea is BS or it could be a combination of the two ?
« Last Edit: August 11, 2019, 10:30:35 PM by philopek »

Sterks

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Re: 2019 sea ice area and extent data
« Reply #2099 on: August 11, 2019, 10:46:08 PM »
Any evidence of this massive surface refreezing in the ESS or the Pacific side in general would be appreciated.
Yes, your pattern recognition ability to observe the increase in concentration in the pacific edge between the 4th and the 10th of August.
I must remember that a gif of just 2 days, several days apart, played quite slowly, gives so much more to my tired old eyes than the gifs of many days running swiftly together. It's the enhanced contrast.
and...
- is that a fairly large Artefact twixt Revolution Island and the Russian shore at 90 East?
- perhaps an even chance for the Parry Channel to open before the end of the month?
- will there just be a great lump of solid ice North of 80 (frayed a bit at the edges) and almost nothing anywhere else by mid-September? If so, still a chance of a record low extent?
I posted the Pacific edge in the main thread, comparing Aug 4 to Aug 9 instead of 10. Artifact free. If you look along the Pacific edge (of which most is already part of the CAB) you’ll notice a relative immobility and an increase of concentration, which is consistent with the spike up in CAB area and relative slowness in Chukchi final decay and Beaufort. It was cold enough for the ponds to refreeze But anyway your numbers suffice.
I’ll won’t post about this any further here.
« Last Edit: August 11, 2019, 11:24:26 PM by Sterks »