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Stephan

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Re: 2019 sea ice area and extent data
« Reply #750 on: May 10, 2019, 06:41:21 PM »
I took the monthly extent value for April 2019 and added it into my long-term plot where I calculate the anomalies from 1979 up to now.
The average April extent is now 14,57 M km². April 2019 had an average extent of 13,46 M km², which is 1,11 M km² less than that average and the lowest April extent since 1979.
In April 2019 the anomaly from the red linear trend line is reduced to -0,06 M km² (calculated this April should have been at 13,52 M km²). For the first time since October 2018 the value is now below that linear trend line. To stay in that position May 2019 must show (slightly) higher than average losses which did not occur in the last ten days.
The slope of the overall trend line has decreased again a tiny little bit (last digit) by one number.

See attached graph.

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #751 on: May 11, 2019, 05:49:32 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

May 10th, 2019:
     11,826,209 km2, a drop of -34,871 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.

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #752 on: May 11, 2019, 07:01:13 AM »
NSIDC NT sea ice extent and area in the Arctic Basin (you know what I mean) are now both below anything previously on the 8th of May.
If we look at JAXA values, we could think that 2019 has lost the lowest values leadership against 2016. But it is interesting the Wipneus post. Looking at the Arctic Basin (Beaufort, Chukchi, ESS, Laptev and Cental Basin), 2019 is lower than 2016.

We will have to wait a couple of weeks at least, to see how 2019 develops.
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 #753 on: May 11, 2019, 11:38:24 AM »
JAXA ARCTIC EXTENT :- 11,826,209 km2(May 10, 2019)

- Extent is 2nd  lowest in the satellite record, 193 k more than 2016
- Extent loss on this day 35k, 35 k less than the average loss of 70 k on this day.
- Extent loss from maximum 2,445 k, 501 k (26%) greater than the average of 1,944k loss from maximum by this day,
- On average 19.7% of the melting season done, with 128 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.89 million km2, 2nd lowest in the satellite record, and 0.71 million km2 above the 2012 low of 3.18 million km2.

On 22nd April, 2016 started its 2 months as the front runner with steep declines in extent.  To become lowest again, 2019 will have to match or exceed the above average extent losses of 2016 from now until at least June. For that reason I have removed 2018 daily change and replaced it with 2016 data on graph Arc2.

Later in the season that will be replaced with 2012 as it becomes the front runner. At the moment 2012 daily loss still below average.

Other Stuff
GFS shows temperature anomalies varying from +2 to +3 celsius over the forecast period, with warmth over most of the Arctic and the CAA as far as Svalbard. Also warmth in Baffin Bay for most of the time.
"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)

oren

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Re: 2019 sea ice area and extent data
« Reply #754 on: May 11, 2019, 01:37:09 PM »
NSIDC NT sea ice extent and area in the Arctic Basin (you know what I mean) are now both below anything previously on the 8th of May.
If we look at JAXA values, we could think that 2019 has lost the lowest values leadership against 2016. But it is interesting the Wipneus post. Looking at the Arctic Basin (Beaufort, Chukchi, ESS, Laptev and Central Basin), 2019 is lower than 2016.

We will have to wait a couple of weeks at least, to see how 2019 develops.
The big difference outside the basin is in the Barents, where 2019 (black line) has 200k km2 more area compared to 2016 (dark green line). This seems to be driven by extra export this year. The difference could easily persist for another month.
As usual, thanks to Wipneus for the charts.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #755 on: May 11, 2019, 02:48:30 PM »
NSIDC Total Area as at 10 May 2019 (5 day trailing average)  10,921,663  km2
               
Total Area         
 10,921,663    km2      
-465,526    km2   <   2010's average.
-343,493    k   <   2018
-829,776    k   <   2000's average.
         
Total Area Change   -32    k   loss
Peripheral Seas   -11    k   loss
Central Seas__   -16    k   loss
Other Seas___   -4    k   loss
         
Peripheral Seas         
Bering _______   -2    k   loss
Baffin  Bay____   -7    k   loss
Greenland____    4    k   gain
Barents ______   -7    k   loss
         
CAB Seas         
Beaufort_____    6    k   gain
CAA_________   -5    k   loss
East Siberian__    1    k   gain
Central Arctic_    1    k   gain
         
Kara_________   -8    k   loss
Laptev_______   -10    k   loss
Chukchi______   -1    k   loss
         
Other Seas         
Okhotsk______   -3    k   loss
St Lawrence___    0    k   gain
Hudson Bay___   -1    k   loss

Area loss 32 k, 17 k less than the 2010's average loss of 49 k on this day.
Total area still 2nd lowest (141k > 2016)

Temperatures
GFS shows temperature anomalies varying from +2 to +3 celsius over the forecast period, with warmth over most of the Central Arctic and the CAA as far as Svalbard. Also warmth in Baffin Bay for most of the time.
"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: 2019 sea ice area and extent data
« Reply #756 on: May 12, 2019, 06:08:05 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

May 11th, 2019:
     11,811,736 km2, a drop of -14,473 km2.
     2019 is 2nd lowest on record.
     (2012 highlighted).
     2013 with not official value. Average calculated.
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 #757 on: May 12, 2019, 06:43:15 AM »
JAXA ARCTIC EXTENT :- 11,811,736 km2(May 11, 2019)

- Extent is 2nd  lowest in the satellite record, 239 k more than 2016
- Extent loss on this day 14k, 49 k less than the average loss of 63 k on this day.
- Extent loss from maximum 2,459 k, 453 k (23%) greater than the average of 2,003k loss from maximum by this day,
- On average 20.3% of the melting season done, with 125 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.94 million km2, 2nd lowest in the satellite record, and 0.76 million km2 above the 2012 low of 3.18 million km2. At the moment 2019 daily loss still well below average and likely to become 3rd lowest below 2018 - perhaps today.

On 22nd April, 2016 started its 2 months as the front runner with steep declines in extent.  To become lowest again, 2019 will have to match or exceed the above average extent losses of 2016 from now until at least June. For that reason I have removed 2018 daily change and replaced it with 2016 data on graph Arc2. Later in the season that will be replaced with 2012 as it becomes the front runner.

Other Stuff
GFS shows temperature anomalies varying from +2 to +3 celsius over the forecast period, with warmth over most of the Arctic and the CAA as far as Svalbard. Also warmth in Baffin Bay for most of the time.
« Last Edit: May 12, 2019, 02:06:30 PM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
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Stephan

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Re: 2019 sea ice area and extent data
« Reply #758 on: May 12, 2019, 08:12:19 AM »
The "2017 feeling" starts to rise - with below average extent losses, now through already most of this month. Will extent losses rise in the next weeks or will 2019 move to 3rd, 4th, 5th place in the table?

Pavel

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Re: 2019 sea ice area and extent data
« Reply #759 on: May 12, 2019, 10:21:15 AM »
Remember the 2012 extent numbers at this time of year. The current weather conditions are unfavorable for the CAB ice due to the possible early surface melting and high ice export. Only the land snow cover extent is relatively good for the ice

pauldry600

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Re: 2019 sea ice area and extent data
« Reply #760 on: May 12, 2019, 12:12:02 PM »
I think a slowdown is now imminent and we will settle in 5th place but the Northern part of Greenland is a worry. It seems to be making the whole ice pack more mobile. Any cyclones and there could be substantial damage.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #761 on: May 12, 2019, 02:27:38 PM »
NSIDC Total Area as at 11 May 2019 (5 day trailing average)  10,903,723  km2
               
Total Area         
 10,903,723    km2      
-427,622    km2   <   2010's average.
-314,792    k   <   2018
-799,195    k   <   2000's average.
         
Total Area Change   -18    k   loss
Peripheral Seas   -7    k   loss
Central Seas__   -9    k   loss
Other Seas___   -1    k   loss
         
Peripheral Seas         
Bering _______   -2    k   loss
Baffin  Bay____   -3    k   loss
Greenland____    3    k   gain
Barents ______   -5    k   loss
         
CAB Seas         
Beaufort_____    5    k   gain
CAA_________   -6    k   loss
East Siberian__    3    k   gain
Central Arctic_    3    k   gain
         
Kara_________   -9    k   loss
Laptev_______   -5    k   loss
Chukchi______   -1    k   loss
         
Other Seas         
Okhotsk______   -4    k   loss
St Lawrence___    1    k   gain
Hudson Bay___    1    k   gain

Area loss 18 k, 35 k less than the 2010's average loss of 53 k on this day.
Total area still 2nd lowest (205k > 2016)

Temperatures
GFS shows temperature anomalies varying from +2 to +3 celsius over the forecast period, with warmth over most of the Central Arctic and the CAA as far as Svalbard. Also warmth in Baffin Bay for most of the time.
"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)

magnamentis

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Re: 2019 sea ice area and extent data
« Reply #762 on: May 12, 2019, 02:46:04 PM »
The "2017 feeling" starts to rise - with below average extent losses, now through already most of this month. Will extent losses rise in the next weeks or will 2019 move to 3rd, 4th, 5th place in the table?

looking at available webcams it's overcast since days, especially in places where the sun would have done a significant job, hence indeed it appears that the early open water has an impact on humidity in the air and that leads to a reduction of insolation at some point.

of course such patterns can change any time, be it for longer or just sufficiently to receive the bullet sooner or later

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #763 on: May 13, 2019, 06:02:05 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

May 12th, 2019:
     11,788,391 km2, a drop of -23,345 km2.
     2019 is now 3rd lowest on record.
     (2012 highlighted).
     2013 with not official value. Average calculated.
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 #764 on: May 13, 2019, 08:30:33 AM »
JAXA ARCTIC EXTENT :- 11,788,391 km2(May 12, 2019)

- Extent is 3rd  lowest in the satellite record, 300 k more than 2016
- Extent loss on this day 23k, 50 k less than the average loss of 73 k on this day.
- Extent loss from maximum 2,483 k, 403 k (21%) greater than the average of 2,080k loss from maximum by this day,
- On average 21.0% of the melting season done, with 124 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.99 million km2, 2nd lowest in the satellite record, and 0.81 million km2 above the 2012 low of 3.18 million km2.

On 22nd April, 2016 started its 2 months as the front runner with steep declines in extent.  To become lowest again, 2019 will have to match or exceed the above average extent losses of 2016 from now until at least June. For that reason I have removed 2018 daily change and replaced it with 2016 data on graph Arc2. Later in the season that will be replaced with 2012 as it becomes the front runner.

Other Stuff
GFS shows temperature anomalies varying from +1.5 to +3 celsius over the forecast period, with warmth over most of the Arctic and the CAA as far as Svalbard. Also warmth in Baffin Bay for most of the time.

At the moment little reason to suppose sea ice loss will accelerate, which makes the cracks and general disintegration of the sea ice all along the Arctic ocean edge from the Beaufort to the Greenland Sea all a bit of a mystery to me.

EDIT. But Frivolousz21 suggests that major changes favouring mega-melt might be on the way - see https://forum.arctic-sea-ice.net/index.php/topic,2591.msg199018.html#msg199018
« Last Edit: May 13, 2019, 08:52:12 AM by gerontocrat »
"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 #765 on: May 13, 2019, 02:06:47 PM »
NSIDC Total Area as at 12 May 2019 (5 day trailing average)  10,874,953  km2
               
Total Area         
 10,874,953    km2      
-396,508    km2   <   2010's average.
-290,138    k   <   2018
-778,170    k   <   2000's average.
         
Total Area Change   -29    k   loss
Peripheral Seas   -16    k   loss
Central Seas__   -10    k   loss
Other Seas___   -4    k   loss
         
Peripheral Seas         
Bering _______   -2    k   loss
Baffin  Bay____   -6    k   loss
Greenland____    2    k   gain
Barents ______   -9    k   loss
         
CAB Seas         
Beaufort_____    2    k   gain
CAA_________   -7    k   loss
East Siberian__    5    k   gain
Central Arctic_    2    k   gain
         
Kara_________   -9    k   loss
Laptev_______   -2    k   loss
Chukchi______   -0    k   loss
         
Other Seas         
Okhotsk______   -4    k   loss
St Lawrence___   -0    k   loss
Hudson Bay___    1    k   gain

Area loss 29 k, 27 k less than the 2010's average loss of 56 k on this day.
Total area still 2nd lowest (269k > 2016)

Temperatures
GFS shows temperature anomalies varying from +1.5 to +3 celsius over the forecast period, with warmth over most of the Central Arctic and the CAA as far as Svalbard. Also warmth in Baffin Bay for most of the time.
« Last Edit: May 13, 2019, 02:13:21 PM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"
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Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #766 on: May 14, 2019, 05:55:28 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

May 13th, 2019:
     11,722,215 km2, a drop of -66,176 km2.
     2019 is 3rd lowest on record.
     (2012 highlighted).
     2013 with not official value. Average calculated.
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 #767 on: May 14, 2019, 10:43:43 AM »
JAXA ARCTIC EXTENT :- 11,722,215 km2(May 13, 2019)

After a solid week of weel below avarge extent loss, a day of above average loss.

- Extent is 3rd  lowest in the satellite record, 351 k more than 2016, just 1k > 2018.
- Extent loss on this day 66k, 17 k more than the average loss of 49 k on this day.
- Extent loss from maximum 2,549 k, 420 k (20%) greater than the average of 2,129k loss from maximum by this day,
- On average 21.5% of the melting season done, with 123 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.97 million km2, 2nd lowest in the satellite record, and 0.79 million km2 above the 2012 low of 3.18 million km2.

On 22nd April, 2016 started its 2 months as the front runner with steep declines in extent.  To become lowest again, 2019 will have to match or exceed the above average extent losses of 2016 from now until at least June. For that reason I have removed 2018 daily change and replaced it with 2016 data on graph Arc2. Later in the season that will be replaced with 2012 as it becomes the front runner.

Other Stuff
GFS shows temperature anomalies varying from +1.5 to +3 celsius over the forecast period, with warmth over most of the Arctic and the CAA as far as Svalbard. Also warmth in Baffin Bay for most of the time.

At the moment little reason to suppose sea ice loss will accelerate, which makes the cracks and general disintegration of the sea ice all along the Arctic ocean edge from the Beaufort to the Greenland Sea all a bit of a mystery to me.

EDIT. But Frivolousz21 (and now others as well) suggest that major changes favouring mega-melt might be on the way - see https://forum.arctic-sea-ice.net/index.php/topic,2591.msg199018.html#msg199018
"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 #768 on: May 14, 2019, 02:25:57 PM »
NSIDC Total Area as at 13 May 2019 (5 day trailing average)  10,840,790 km2
               
Total Area         
 10,840,790    km2      
-370,157    km2   <   2010's average.
-251,543    k   <   2018
-763,985    k   <   2000's average.
         
Total Area Change   -34    k   loss
Peripheral Seas   -22    k   loss
Central Seas__   -10    k   loss
Other Seas___   -3    k   loss
         
Peripheral Seas         
Bering _______   -2    k   loss
Baffin  Bay____   -8    k   loss
Greenland____    4    k   gain
Barents ______   -15    k   loss
         
CAB Seas         
Beaufort_____   -2    k   loss
CAA_________   -8    k   loss
East Siberian__    9    k   gain
Central Arctic_   -1    k   loss
         
Kara_________   -8    k   loss
Laptev_______    3    k   gain
Chukchi______   -3    k   loss
         
Other Seas         
Okhotsk______   -2    k   loss
St Lawrence___   -1    k   loss
Hudson Bay___    0    k   gain

Area loss 34 k, 26 k less than the 2010's average loss of 60 k on this day.
Total area still 2nd lowest (318k > 2016)

Temperatures
GFS shows temperature anomalies varying from +1.5 to +3 celsius over the forecast period, with warmth over most of the Central Arctic and the CAA as far as Svalbard. Also warmth in Baffin Bay for most of the time.
"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: 2019 sea ice area and extent data
« Reply #769 on: May 15, 2019, 05:47:40 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

May 14th, 2019:
     11,657,225 km2, a drop of -64,990 km2.
     2019 is now 2nd lowest on record.
     (2012 highlighted).
     2013 with not official value. Average calculated.
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 #770 on: May 15, 2019, 09:55:35 AM »
JAXA ARCTIC EXTENT :- 11,657,225 km2(May 14, 2019)

After a solid week of well below avarge extent loss, 2 days of above average loss.

- Extent is back to 2nd  lowest in the satellite record, 363 k > 2016, just 21k < 2018.
- Extent loss on this day 65k, 14 k more than the average loss of 51 k on this day.
- Extent loss from maximum 2,614 k, 435 k (20%) greater than the average of 2,180k loss from maximum by this day,
- On average 22.1% of the melting season done, with 122 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.96 million km2, 2nd lowest in the satellite record, and 0.78 million km2 above the 2012 low of 3.18 million km2.

On 22nd April, 2016 started its 2 months as the front runner with steep declines in extent.  To become lowest again, 2019 will have to match or exceed the above average extent losses of 2016 from now until at least June. For that reason I have removed 2018 daily change and replaced it with 2016 data on graph Arc2. Later in the season that will be replaced with 2012 as it becomes the front runner.

Other Stuff
GFS shows temperature anomalies varying from +1.5 to +3.5 celsius over the forecast period, with warmth over most of the Arctic and the CAA as far as Svalbard. Also warmth in Baffin Bay for most of the time.

At the moment little reason to suppose sea ice loss will accelerate, which makes the general disintegration of the sea ice all along the Arctic ocean edge from the Beaufort to the Greenland Sea all a bit of a mystery to me. But several posts on the melting season suggest that major changes favouring mega-melt might be in train.

But as far as melting is concerned, at less than 25% of melting done, the season is far from over.
"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 #771 on: May 15, 2019, 06:34:16 PM »
NSIDC Total Area as at 14 May 2019 (5 day trailing average)  10,791,678 km2
               
Total Area         
 10,791,678    km2      
-352,977    km2   <   2010's average.
-228,514    k   <   2018
-761,587    k   <   2000's average.
         
Total Area Change   -49    k   loss
Peripheral Seas   -29    k   loss
Central Seas__   -9    k   loss
Other Seas___   -11    k   loss
         
Peripheral Seas         
Bering _______   -2    k   loss
Baffin  Bay____   -11    k   loss
Greenland____   -0    k   loss
Barents ______   -16    k   loss
         
CAB Seas         
Beaufort_____   -4    k   loss
CAA_________   -7    k   loss
East Siberian__    9    k   gain
Central Arctic_   -5    k   loss
         
Kara_________   -7    k   loss
Laptev_______    8    k   gain
Chukchi______   -4    k   loss
         
Other Seas         
Okhotsk______   -2    k   loss
St Lawrence___   -0    k   loss
Hudson Bay___   -9    k   loss

Area loss 49 k, 12 k less than the 2010's average loss of 61 k on this day.
Total area still 2nd lowest (362k > 2016)

Temperatures
GFS shows temperature anomalies varying from +1.5 to +3.5 celsius over the forecast period, with warmth over most of the Central Arctic, the CAA and Hudson Bay. Also warmth in Baffin Bay  for most of the time.


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FishOutofWater

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Re: 2019 sea ice area and extent data
« Reply #772 on: May 15, 2019, 07:43:32 PM »
High pressure and clockwise rotation of the ice pack induce Eckman upwelling in the near shore waters of Alaska and Canada. The Coriolis effect deflects the ice towards the center of the high and it is replaced by water from below. If high pressure persists it slowly pumps up warm water from the Atlantic layer along the continental shelf.

At the moment little reason to suppose sea ice loss will accelerate, which makes the general disintegration of the sea ice all along the Arctic ocean edge from the Beaufort to the Greenland Sea all a bit of a mystery to me.

Persistent high pressure in May June and July is not good for Arctic sea ice, especially in the Beaufort sea.


uniquorn

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Re: 2019 sea ice area and extent data
« Reply #773 on: May 16, 2019, 12:27:41 AM »
High pressure and clockwise rotation of the ice pack induce Eckman upwelling <snippage>
replied here https://forum.arctic-sea-ice.net/index.php/topic,2417.msg199462.html#msg199462

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #774 on: May 16, 2019, 05:52:04 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

May 15th, 2019:
     11,568,100 km2, a drop of -89,125 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.

Ktb

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Re: 2019 sea ice area and extent data
« Reply #775 on: May 16, 2019, 06:31:54 AM »
Bimonthly BOE evaluation

May 15 extent was 11,568,100 km^2. With on average 121 days to go until the end of the melt season on September 13th, we now require a daily drop of -87,323 km^2 for a BOE to occur. (See Attachment 1).

There have been many days of below average melt, and several days of above average melt. Total extent loss thus far in May is -739,276 km^2. And total extent loss so far this season is -2,705,021 km^2. This has resulted in the current average daily drop of -42,266 km^2. If the month of May ended today, this would the 3rd fastest daily loss from maximum to the end of May (behind 2010 at a whopping -57,318 km^2 per day, and 2014 at -42,541 km^2 per day). (See Attachment 2).

Looking only at the month of May (so far), we have averaged -49,285 km^2 per day. This average daily drop places May 2019 as 8th out of 13 (2007-2019) in average daily May melt (See Attachment 3).
Although we still have 16 days to go this month, and many of the ASIF gods are becoming worried about the high pressure setup forecast by GFS.

No 2nd post for mid monthlies, don't have the data calculated and I am traveling so even this post was unexpected for me.

Edit: was tired and missed 2,000 km^2 so the averages will be slightly lower. My mistake.
« Last Edit: May 18, 2019, 09:57:24 PM by Ktb »
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FishOutofWater

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Re: 2019 sea ice area and extent data
« Reply #776 on: May 16, 2019, 06:39:22 AM »
FYI the ECMWF & GFS agree on high pressure over the Arctic over the next ten days. They differ on details but it not a "good for shit" forecast. It's a result of large scale subsidence and spin coupling of warm air domes in the troposphere and stratosphere. We're seeing "big picture" phenomena.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #777 on: May 16, 2019, 08:20:31 AM »
JAXA ARCTIC EXTENT :- 11,568,100 km2(May 15, 2019)

After a solid week of well below average extent loss, 3 days of above average loss.

- Extent is back to 2nd  lowest in the satellite record, 306 k > 2016, 104 k < 2018.
- Extent loss on this day 89k, 48 k more than the average loss of 41 k on this day.
- Extent loss from maximum 2,703 k, 482 k (22%) greater than the average of 2,221k loss from maximum by this day,
- On average 22.5% of the melting season done, with 121 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.91 million km2, 2nd lowest in the satellite record, and 0.73 million km2 above the 2012 low of 3.18 million km2.

On 22nd April, 2016 started its 2 months as the front runner with steep declines in extent.  To become lowest again, 2019 will have to match or exceed the above average extent losses of 2016 from now until at least June. For that reason I have removed 2018 daily change and replaced it with 2016 data on graph Arc2. Later in the season that will be replaced with 2012 as it becomes the front runner.

Other Stuff
GFS shows temperature anomalies varying from +1.5 to +3 celsius over the forecast period, with warmth over most of the Arctic and the CAA as far as Svalbard. Also warmth in Baffin Bay for most of the time.

At the moment little reason to suppose sea ice loss will accelerate, which makes the general disintegration of the sea ice all along the Arctic ocean edge from the Beaufort to the Greenland Sea all a bit of a mystery to me. But several posts on the melting season still suggest that major changes favouring mega-melt might be in train.

On average, less than 25% of the melting season is done.
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #778 on: May 16, 2019, 03:04:52 PM »
NSIDC Total Area as at 15 May 2019 (5 day trailing average)  10,746,321 km2
               
Total Area         
 10,746,321    km2      
-333,628    km2   <   2010's average.
-202,061    k   <   2018
-751,156    k   <   2000's average.
         
Total Area Change   -45    k   loss
Peripheral Seas   -31    k   loss
Central Seas__   -9    k   loss
Other Seas___   -6    k   loss
         
Peripheral Seas         
Bering _______   -1    k   loss
Baffin  Bay____   -13    k   loss
Greenland____   -1    k   loss
Barents ______   -15    k   loss
         
CAB Seas         
Beaufort_____   -8    k   loss
CAA_________   -6    k   loss
East Siberian__    8    k   gain
Central Arctic_   -8    k   loss
         
Kara_________    1    k   gain
Laptev_______    11    k   gain
Chukchi______   -6    k   loss
         
Other Seas         
Okhotsk______   -2    k   loss
St Lawrence___    2    k   gain
Hudson Bay___   -5    k   loss

Area loss 45 k, 21 k less than the 2010's average loss of 66 k on this day.
Total area still 2nd lowest (385k > 2016)

Temperatures
GFS shows temperature anomalies varying from +1.5 to +3.5 celsius over the forecast period, with warmth over most of the Central Arctic, the CAA and Hudson Bay. Also warmth in Baffin Bay  for most of the time.
"Para a Causa do Povo a Luta Continua!"
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HelloMeteor

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Re: 2019 sea ice area and extent data
« Reply #779 on: May 17, 2019, 01:16:18 AM »
Been lurking for a year. I was introduced to any significant degree to the idea of arctic sea ice loss and its effects, mostly albedo, and the latent heat of freezing or whatever it's called by a certain "guy" who seems to be somewhat notorious around here. That guy's pronouncements were interesting, so I started paying more attention. I've always been a skeptic of just about everything, and I'm still pretty skeptical about those pronouncements, and many of the far lest drastic ones. However the basic thermodynamics of the conseqences of the loss of arctic sea ice struck me as 100% rational, and the arctic sea ice death spiral certainly shows us trending towards zero. The self-reinforcing nature of the trend makes sense. So I'm less skeptical about that.

Anyway, I've been watching the ice for a year now. I'm making a video with every daily picture from NSIDC. The center image from the site below. How do I put a video in the message? Or how do I turn it into a GIF before doing that?

https://nsidc.org/arcticseaicenews/

Juan C. García

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Re: 2019 sea ice area and extent data
« Reply #780 on: May 17, 2019, 05:50:58 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

May 16th, 2019:
     11,488,339 km2, a drop of -79,761 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 #781 on: May 17, 2019, 05:53:43 AM »
JAXA ARCTIC EXTENT :- 11,488,339 km2(May 16, 2019)

4th day of above average loss.

- Extent is back to 2nd lowest in the satellite record, 290 k > 2016, 143 k < 2018.
- Extent loss on this day 80k, 20 k more than the average loss of 60 k on this day.
- Extent loss from maximum 2,783 k, 502 k (22%) greater than the average of 2,281k loss from maximum by this day,
- On average 23.1% of the melting season done, with 120 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.89 million km2, 2nd lowest in the satellite record, and 0.71 million km2 above the 2012 low of 3.18 million km2.

On 22nd April, 2016 started its 2 months as the front runner with steep declines in extent.  To become lowest again, 2019 will have to match or exceed the above average extent losses of 2016 from now until at least June. For that reason I have removed 2018 daily change and replaced it with 2016 data on graph Arc2. Later in the season that will be replaced with 2012 as it becomes the front runner.

Other Stuff
GFS shows temperature anomalies varying from +1.2 to +3.2 celsius over the forecast period, with warmth over most of the Arctic and the CAA as far as Svalbard. Also warmth in Baffin Bay for most of the time.

At the moment still little reason to suppose sea ice loss will accelerate further. But several posts on the melting season thread suggest (with growing confidence?) that major changes favouring mega-melt might be in train.

On average, less than 25% of the melting season is done.
"Para a Causa do Povo a Luta Continua!"
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Rich

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Re: 2019 sea ice area and extent data
« Reply #782 on: May 17, 2019, 06:24:08 AM »


At the moment still little reason to suppose sea ice loss will accelerate further.

So..just in the interest of keeping it fresh...what variables are you taking into consideration when you suggest that there is no reason to suppose sea ice loss will accelerate?

For clarification, I'm grateful for the effort that people like you put into providing the data that you do. Thank you!!

But I'm also coming from a perspective that we're heading for an inevitable BOE / climate apocalypse in coming decades and that most people here are just here to witness that and share the experience.

There's a balance of people who are seeing the potential for short-term demise and those like yourself who are saying...not yet.

Anyway ..I'm curious to know what variables you consider when there are differences of opinion. I sincerely want to learn.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #783 on: May 17, 2019, 06:47:14 AM »


At the moment still little reason to suppose sea ice loss will accelerate further.

So..just in the interest of keeping it fresh...what variables are you taking into consideration when you suggest that there is no reason to suppose sea ice loss will accelerate?

For clarification, I'm grateful for the effort that people like you put into providing the data that you do. Thank you!!

But I'm also coming from a perspective that we're heading for an inevitable BOE / climate apocalypse in coming decades and that most people here are just here to witness that and share the experience.

There's a balance of people who are seeing the potential for short-term demise and those like yourself who are saying...not yet.

Anyway ..I'm curious to know what variables you consider when there are differences of opinion. I sincerely want to learn.
My statement referred to current forecast period of around 10 days simply from looking at fairly low +ve temperature anomalies and current fairly strong extent loss. i think it is far too early to look at the end of season minimum with any confidence at all. Others disagree.
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El Cid

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Re: 2019 sea ice area and extent data
« Reply #784 on: May 17, 2019, 07:56:48 AM »
gerontocrat,

I believe that at this time of the year (near peak insolation) pressure is the key, not temperature (though the two are related). If we get constant high pressure, ie. constant sunlight all over the Arctic, then that is very detrimental for ice.

(sorry for the OT)

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Re: 2019 sea ice area and extent data
« Reply #785 on: May 17, 2019, 09:01:28 AM »
Anyway, I've been watching the ice for a year now. I'm making a video with every daily picture from NSIDC. The center image from the site below. How do I put a video in the message? Or how do I turn it into a GIF before doing that?

You can click 'Attachments and other options' below the comment box when writing a comment, and then you'll be able to choose files for attachments. MP4, M4V, MOV and AVI are among the allowed file types.

Alternatively, you can upload the video somewhere else and then link to it.

Please, don't make the file too large and post it in the 2019 melting season thread, unless it's specifically about sea ice area and extent data.
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b_lumenkraft

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Re: 2019 sea ice area and extent data
« Reply #786 on: May 17, 2019, 09:18:54 AM »
Or how do I turn it into a GIF before doing that?

There are web services doing this. I like https://ezgif.com.

Hello and welcome to the forum. :)

Rich

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Re: 2019 sea ice area and extent data
« Reply #787 on: May 17, 2019, 09:23:59 AM »


At the moment still little reason to suppose sea ice loss will accelerate further.

So..just in the interest of keeping it fresh...what variables are you taking into consideration when you suggest that there is no reason to suppose sea ice loss will accelerate?

For clarification, I'm grateful for the effort that people like you put into providing the data that you do. Thank you!!

But I'm also coming from a perspective that we're heading for an inevitable BOE / climate apocalypse in coming decades and that most people here are just here to witness that and share the experience.

There's a balance of people who are seeing the potential for short-term demise and those like yourself who are saying...not yet.

Anyway ..I'm curious to know what variables you consider when there are differences of opinion. I sincerely want to learn.
My statement referred to current forecast period of around 10 days simply from looking at fairly low +ve temperature anomalies and current fairly strong extent loss. i think it is far too early to look at the end of season minimum with any confidence at all. Others disagree.

Thanks for the reply. As someone trying to learn, each piece helps. My inference is that you see atmospheric temperature as the dominant variable.

It would be interest to get some kind of sense of how people rank the various variables.

As a newbie, I would guess water temperature is at least up there with atmospheric temperature . Sunlight has been pointed out. The spin which brings ice to Fram seems important. Nares being open with a steady throughput. Wind. The thickness of the ice. The level of surface fracturing.

Thanks for your patience. I'm just trying to get oriented. Asking questions helps.

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #788 on: May 17, 2019, 11:45:55 AM »

It would be interest to get some kind of sense of how people rank the various variables.

As a newbie, I would guess water temperature is at least up there with atmospheric temperature . Sunlight has been pointed out. The spin which brings ice to Fram seems important. Nares being open with a steady throughput. Wind. The thickness of the ice. The level of surface fracturing.

Thanks for your patience. I'm just trying to get oriented. Asking questions helps.
For discussions on the various parameters that influence sea ice area and extent the 2019 melting season thread (and other threads such as salinity) is where you need to go. There you will find the posts on the weather, the climate, the sea temperatures, the ocean currents etc etc etc. There you will also find the more you know the less you know.

This thread is mostly just about the data itself. I only make a comment on my posts in this thread about where the very short-term direction of travel may be.

Most of us also use the "Stupid Questions" thread from time to time. You will get good answers and links to places within this forum and elsewhere.  It is a big and wide-ranging forum. Good hunting.
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gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #789 on: May 17, 2019, 03:56:09 PM »
NSIDC Total Area as at 16 May 2019 (5 day trailing average)  10,680,060 km2
               
Total Area         
 10,680,060    km2      
-336,508    km2   <   2010's average.
-204,868    k   <   2018
-761,718    k   <   2000's average.
         
Total Area Change   -66    k   loss
Peripheral Seas   -36    k   loss
Central Seas__   -21    k   loss
Other Seas___   -9    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -16    k   loss
Greenland____   -2    k   loss
Barents ______   -18    k   loss
         
CAB Seas         
Beaufort_____   -15    k   loss
CAA_________   -7    k   loss
East Siberian__    7    k   gain
Central Arctic_   -7    k   loss
         
Kara_________   -2    k   loss
Laptev_______    11    k   gain
Chukchi______   -7    k   loss
         
Other Seas         
Okhotsk______   -2    k   loss
St Lawrence___    1    k   gain
Hudson Bay___   -8    k   loss

Area loss 66 k, 1 k more than the 2010's average loss of 65 k on this day.
Total area still 2nd lowest (363k > 2016)

Temperatures
GFS shows temperature anomalies varying from +1.2 to +3.2 celsius over the forecast period, with warmth over most of the Central Arctic, the CAA and Hudson Bay. Also warmth in Baffin Bay  for most of the time.
"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 #790 on: May 17, 2019, 05:02:06 PM »
The Perils of Projections?

At the moment 2019 NSIDC Sea Ice Area is some 360k, circa one week's melt,  above that of 2016 (currently lowest area). However, that overall position conceals very large differences between various seas .

For example, sea ice area in the Chukchi Sea has been lowest in the satellite record for 58 out of 135 days in 2019 so far. In 2016, sea ice loss was merely average. In contrast, in 2016 ice in the Beaufort Sea, just next door, crashed. 2019 area loss , though above average, is far more modest.

On the Atlantic side, in 2016 the Barents sea ice melted out extremely early. In 2019, although sea ice loss has rapidly increased in the last few days, area is still a bit above the 2010's average.

Such extreme variations year by year, sea by sea, suggests great regional climatic variation within the general framework of AGW of n degrees per decade. So I don't have a clue what will happen in the remaining 75+ % of the 2019 melting season - not in total and not where in the Arctic the above and below average sea ice losses will be.

But, what does that matter? So here's my forecast for the 2019 Jaxa Extent minimum.
4,000,000 km2- not a km2 more, not a km2 less;  on September 13th - not a day before, not a day later.
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Shared Humanity

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Re: 2019 sea ice area and extent data
« Reply #791 on: May 17, 2019, 05:28:52 PM »
The Perils of Projections?

At the moment 2019 NSIDC Sea Ice Area is some 360k, circa one week's melt,  above that of 2016 (currently lowest area). However, that overall position conceals very large differences between various seas .

For example, sea ice area in the Chukchi Sea has been lowest in the satellite record for 58 out of 135 days in 2019 so far. In 2016, sea ice loss was merely average. In contrast, in 2016 ice in the Beaufort Sea, just next door, crashed. 2019 area loss , though above average, is far more modest.

On the Atlantic side, in 2016 the Barents sea ice melted out extremely early. In 2019, although sea ice loss has rapidly increased in the last few days, area is still a bit above the 2010's average.

Such extreme variations year by year, sea by sea, suggests great regional climatic variation within the general framework of AGW of n degrees per decade. So I don't have a clue what will happen in the remaining 75+ % of the 2019 melting season - not in total and not where in the Arctic the above and below average sea ice losses will be.

But, what does that matter? So here's my forecast for the 2019 Jaxa Extent minimum.
4,000,000 km2- not a km2 more, not a km2 less;  on September 13th - not a day before, not a day later.

I am not certain but wasn't ice export into the Barents fairly pronounced this winter? This may account for the higher totals.

Thank you for this analysis by the way.

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Re: 2019 sea ice area and extent data
« Reply #792 on: May 18, 2019, 12:07:12 AM »
 I figure this is the best place for this.
Slater sea ice anomaly persistence model predicting 8.47 million km2 on July 6.

I believe the Charctic graph (third attachment) is the proper comparison, apologies if I'm mistaken.
Lowest for that date is 2012, with 8.796 million km2

I'm not saying it'll be correct, but I found it interesting.
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Re: 2019 sea ice area and extent data
« Reply #793 on: May 18, 2019, 05:45:40 AM »
[ADS NIPR VISHOP (JAXA)] Arctic Sea Ice Extent.

May 17th, 2019:
     11,421,099 km2, a drop of -67,240 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 #794 on: May 18, 2019, 09:38:20 AM »
JAXA ARCTIC EXTENT :- 11,421,099 km2(May 17, 2019)

- Extent is back to 2nd lowest in the satellite record, 276 k > 2016, 167 k < 2018.
- Extent loss on this day 67 k, 8 k more than the average loss of 59 k on this day.
- Extent loss from maximum 2,850 k, 510 k (22%) greater than the average of 2,339k loss from maximum by this day,
- On average 23.7% of the melting season done, with 119 days to average date of minimum (13 September).

The Perils of Projections.
Average remaining melt would give a minimum of 3.88 million km2, 2nd lowest in the satellite record, and 0.70 million km2 above the 2012 low of 3.18 million km2.

On 22nd April, 2016 started its 2 months as the front runner with steep declines in extent.  To become lowest again, 2019 will have to match or exceed the above average extent losses of 2016 from now until at least mid-late June. For that reason I have removed 2018 daily change and replaced it with 2016 data on graph Arc2. Later in the season that will be replaced with 2012 as it becomes the front runner.

Other Stuff
GFS shows temperature anomalies varying from +1.2 to +3.0 celsius over the forecast period, with warmth over most of the Arctic and the CAA as far as Svalbard. Also warmth in Baffin Bay for most of the time.

At the moment still little reason to suppose sea ice loss will accelerate further. But several posts on the melting season thread suggest (with growing confidence?) that major changes favouring mega-melt might be in train.

On average, less than 25% of the melting season is done.
"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)

bbr2314

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Re: 2019 sea ice area and extent data
« Reply #795 on: May 18, 2019, 09:52:37 AM »
The Slater model is usually quite accurate. But the numbers are actually even worse than face value as the map shows Hudson and Baffin still significantly intact by that point. Beyond already venturing into record territory at that point, that would set us up for a very substantial cliff through both July and August (like normal, but worse, as both of those areas will melt out fully -- 99% anyways).

gerontocrat

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Re: 2019 sea ice area and extent data
« Reply #796 on: May 18, 2019, 03:12:05 PM »
NSIDC Total Area as at 17 May 2019 (5 day trailing average)  10,611,807 km2
               
Total Area         
 10,611,807    km2      
-343,850    km2   <   2010's average.
-213,374    k   <   2018
-772,164    k   <   2000's average.
         
Total Area Change   -68    k   loss
Peripheral Seas   -38    k   loss
Central Seas__   -25    k   loss
Other Seas___   -5    k   loss
         
Peripheral Seas         
Bering _______   -0    k   loss
Baffin  Bay____   -17    k   loss
Greenland____   -3    k   loss
Barents ______   -18    k   loss
         
CAB Seas         
Beaufort_____   -18    k   loss
CAA_________   -4    k   loss
East Siberian__    4    k   gain
Central Arctic_   -6    k   loss
         
Kara_________   -7    k   loss
Laptev_______    12    k   gain
Chukchi______   -6    k   loss
         
Other Seas         
Okhotsk______   -2    k   loss
St Lawrence___    0    k   gain
Hudson Bay___   -4    k   loss

Area loss 68 k, 5 k more than the 2010's average loss of 63 k on this day.
Total area still 2nd lowest (340k > 2016)

Temperatures
GFS shows temperature anomalies varying from +1.2 to +3.2 celsius over the forecast period, with warmth over most of the Central Arctic, the CAA and Hudson Bay. Also warmth in Baffin Bay  for most of the time.

It will be interesting to see if the prognostications of imminent ice armageddon (Slater projections, various posts in the melting thread) translate into HUGE ice loss. Looking at temperature alone suggests more like a bit above average at least for the next week or so.
"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: 2019 sea ice area and extent data
« Reply #797 on: May 19, 2019, 04:09:13 AM »
With the pollution in Mexico City and surrounding, I am starting to be sick, so I will go early to bed.
Can someone else post the JAXA data?
Thanks.
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.

wdmn

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Re: 2019 sea ice area and extent data
« Reply #798 on: May 19, 2019, 05:47:08 AM »
May 18th, 2019:
     11,374,861 km2, a drop of -46,238 km2.
     2019 is 2nd lowest on record.

epiphyte

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Re: 2019 sea ice area and extent data
« Reply #799 on: May 19, 2019, 08:20:26 AM »

It will be interesting to see if the prognostications of imminent ice armageddon (Slater projections, various posts in the melting thread) translate into HUGE ice loss. Looking at temperature alone suggests more like a bit above average at least for the next week or so.

A couple of those prognostications were mine, so speaking only for myself, I'd re-iterate that at this time of year, changes in extent are _not_ an indicator of melt progress vs. previous years. It's entirely possible that the next 2-3 weeks will do damage that will result in a record low at the end of the season, but there will be little net change in extent. Depending on where it's happening, an extent _increase_ may itself signify a death blow for the ice in that region.