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Tor Bejnar

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Re: Sea Ice Extent around Antarctica
« Reply #1500 on: October 01, 2020, 06:03:34 PM »
You mean I cannot celebrate 3 years of "recovery"? (in any meaningful way)
 :o ::) :P
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1501 on: October 01, 2020, 09:06:37 PM »
You mean I cannot celebrate 3 years of "recovery"? (in any meaningful way)
 :o ::) :P
In my not particularly humble opinion (IMNPHO), no - you cannot. Maybe (or maybe not) all that extra sea ice is because the Antarctic Continental ice sheet is losing mass at an accelerating rate (very cold freshwater forming a lower density surface layer on top of warmer salty ocean water).

But then who needs meaning to celebrate? Where's the booze?



« Last Edit: October 02, 2020, 02:01:39 PM by gerontocrat »
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Stephen

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Re: Sea Ice Extent around Antarctica
« Reply #1502 on: October 02, 2020, 02:00:47 AM »
....very cold freshwater forming a lower density surface layer on top of warmer salty ocean water...

[/quote]

That's part of it, but I recall a study which concluded that the main reason was that stronger katabatic winds were pushing existing near-coast ice further out, allowing more ice to form on the coast.
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1503 on: October 02, 2020, 02:03:14 PM »
Quote
....very cold freshwater forming a lower density surface layer on top of warmer salty ocean water...


That's part of it, but I recall a study which concluded that the main reason was that stronger katabatic winds were pushing existing near-coast ice further out, allowing more ice to form on the coast.
Another maybe to add to the long list of maybes?
« Last Edit: October 04, 2020, 01:36:22 PM by gerontocrat »
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1504 on: October 04, 2020, 01:42:45 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,719,023 KM2 as at 03-Oct-2020

- Extent GAIN on this day 28k, 37 k more than the average LOSS on this day (of the last 10 years) of 9k,
- Extent loss from maximum on this date is -0.14 million km2, 0.12 million km2, (45%) less than the 10 year average of 0.26 million km2.
- Extent is at position #27 in the satellite record of which 15 lower values are in the years before 2000
- Extent is  776 k MORE than 2016
- Extent is  949 k MORE than 2017
- Extent is  700 k MORE than 2018
- Extent is  498 k MORE than 2019
- Extent is  313 k MORE than the 1980's Average

- On average 1.6% of ice loss  from maximum to minimum done, and 141 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.97 million km2, 0.82 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
N.B. Click on image  for full-size
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1505 on: October 06, 2020, 01:46:52 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,653,415 KM2 as at 05-Oct-2020

- Extent loss on this day 37k, 43 k more than the average gain on this day (of the last 10 years) of 6k,
- Extent loss from maximum on this date is 0.21 million km2, 0.06 million km2, (21%) less than the 10 year average of 0.26 million km2.
- Extent is at position #26 in the satellite record of which 15 lower values are in the years before 2000
- Extent is  675 k MORE than 2016
- Extent is  707 k MORE than 2017
- Extent is  666 k MORE than 2018
- Extent is  431 k MORE than 2019
- Extent is  300 k MORE than the 1980's Average

- On average 1.6% of ice loss  from maximum to minimum done, and 139 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.91 million km2, 0.76 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
N.B. Click on image  for full-size
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1506 on: October 08, 2020, 01:00:29 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,627,311 KM2 as at 07-Oct-2020

- Extent loss on this day 19k, 8 k less than the average loss on this day (of the last 10 years) of 27k,
- Extent loss from maximum on this date is 0.23 million km2, 0.08 million km2, (25%) less than the 10 year average of 0.31 million km2.
- Extent is at position #31 in the satellite record of which 17 lower values are in the years before 2000
- Extent is  797 k MORE than 2016
- Extent is  636 k MORE than 2017
- Extent is  654 k MORE than 2018
- Extent is  431 k MORE than 2019
- Extent is  345 k MORE than the 1980's Average

- On average 2.0% of ice loss  from maximum to minimum done, and 137 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.91 million km2, 0.77 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
N.B. Click on image  for full-size
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1507 on: October 11, 2020, 10:06:44 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,510,836 KM2 as at 10-Oct-2020

- Extent loss on this day 63k, 40 k more than the average loss on this day (of the last 10 years) of 23k,
- Extent loss from maximum on this date is 0.35 million km2, 0.06 million km2, (14%) less than the 10 year average of 0.41 million km2.
- Extent is at position #30 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  715 k MORE than 2016
- Extent is  515 k MORE than 2017
- Extent is  643 k MORE than 2018
- Extent is  386 k MORE than 2019
- Extent is  270 k MORE than the 1980's Average

- On average 2.5% of ice loss  from maximum to minimum done, and 134 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.88 million km2, 0.73 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
N.B. Click on image  for full-size
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1508 on: October 12, 2020, 12:46:37 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,422,743 KM2 as at 11-Oct-2020

- Extent loss on this day 88k, 51 k more than the average loss on this day (of the last 10 years) of 37k,
- Extent loss from maximum on this date is 0.44 million km2, 0.01 million km2, (3%) less than the 10 year average of 0.45 million km2.
- Extent is at position #28 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  648 k MORE than 2016
- Extent is  473 k MORE than 2017
- Extent is  505 k MORE than 2018
- Extent is  303 k MORE than 2019
- Extent is  200 k MORE than the 1980's Average

- On average 2.8% of ice loss  from maximum to minimum done, and 133 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.83 million km2, 0.68 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
N.B. Click on image  for full-size
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1509 on: October 14, 2020, 12:33:16 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,361,413 KM2 as at 13-Oct-2020

- Extent loss on this day 17k, 26 k less than the average loss on this day (of the last 10 years) of 43k,
- Extent loss from maximum on this date is 0.50 million km2, 0.03 million km2, (5%) less than the 10 year average of 0.53 million km2.
- Extent is at position #27 in the satellite record of which 15 lower values are in the years before 2000
- Extent is  624 k MORE than 2016
- Extent is  523 k MORE than 2017
- Extent is  477 k MORE than 2018
- Extent is  225 k MORE than 2019
- Extent is  194 k MORE than the 1980's Average

- On average 3.3% of ice loss  from maximum to minimum done, and 131 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.85 million km2, 0.70 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
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Tom_Mazanec

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Re: Sea Ice Extent around Antarctica
« Reply #1510 on: October 14, 2020, 02:54:39 PM »
Antarctica ice is at the middle of the satellite record, maybe even above average. Is the southern ice area/extent immune to the early AGW we have had?
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grixm

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Re: Sea Ice Extent around Antarctica
« Reply #1511 on: October 14, 2020, 03:50:02 PM »
Antarctica ice is at the middle of the satellite record, maybe even above average. Is the southern ice area/extent immune to the early AGW we have had?

I believe an argument is that the sea ice is protected by cold and non-saline meltwater from the Antarctic continent. And the more the continent melts due to global warming, the more the sea ice is protected. So this leads to the sea ice being in equilibrium regardless of whether the global temperature goes up or down, at least up to a point. We can see something similar happening around Greenland as well: https://en.wikipedia.org/wiki/Cold_blob_(North_Atlantic)

gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1512 on: October 16, 2020, 10:54:43 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,281,471 KM2 as at 15-Oct-2020

- Extent loss on this day 34k, 6 k less than the average loss on this day (of the last 10 years) of 40k,
- Extent loss from maximum on this date is 0.58 million km2, 0.01 million km2, (2%) less than the 10 year average of 0.59 million km2.
- Extent is at position #28 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  631 k MORE than 2016
- Extent is  535 k MORE than 2017
- Extent is  447 k MORE than 2018
- Extent is  226 k MORE than 2019
- Extent is  176 k MORE than the 1980's Average

- On average 3.7% of ice loss  from maximum to minimum done, and 129 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.84 million km2, 0.69 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1513 on: October 17, 2020, 12:05:18 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,293,247 KM2 as at 16-Oct-2020

- Extent gain on this day 12k, 43 k less than the average loss on this day (of the last 10 years) of 31k,
- Extent loss from maximum on this date is 0.57 million km2, 0.07 million km2, (11%) less than the 10 year average of 0.64 million km2.
- Extent is at position #28 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  735 k MORE than 2016
- Extent is  581 k MORE than 2017
- Extent is  510 k MORE than 2018
- Extent is  243 k MORE than 2019
- Extent is  221 k MORE than the 1980's Average

- On average 4.0% of ice loss  from maximum to minimum done, and 128 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.88 million km2, 0.73 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
N.B. Click on image  for full-size
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1514 on: October 20, 2020, 12:30:20 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,208,308 KM2 as at 19-Oct-2020

- Extent loss on this day 24k, 22 k less than the average loss on this day (of the last 10 years) of 46k,
- Extent loss from maximum on this date is 0.65 million km2, 0.13 million km2, (17%) less than the 10 year average of 0.78 million km2.
- Extent is at position #29 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  947 k MORE than 2016
- Extent is  574 k MORE than 2017
- Extent is  578 k MORE than 2018
- Extent is  326 k MORE than 2019
- Extent is  258 k MORE than the 1980's Average

- On average 4.9% of ice loss  from maximum to minimum done, and 125 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.95 million km2, 0.81 million km2 above the 2017 record low minimum of 2.15 million km2.
______________________________________________
Melting continues at a slow pace.
___________________________________________________________
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1515 on: October 21, 2020, 10:50:55 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,170,098 KM2 as at 20-Oct-2020

- Extent loss on this day 38k, 20 k less than the average loss on this day (of the last 10 years) of 58k,
- Extent loss from maximum on this date is 0.69 million km2, 0.14 million km2, (16%) less than the 10 year average of 0.83 million km2.
- Extent is at position #29 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  958 k MORE than 2016
- Extent is  572 k MORE than 2017
- Extent is  627 k MORE than 2018
- Extent is  347 k MORE than 2019
- Extent is  260 k MORE than the 1980's Average

- On average 5.2% of ice loss  from maximum to minimum done, and 124 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.97 million km2, 0.83 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
N.B. Click on image  for full-size
"Para a Causa do Povo a Luta Continua!"
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Paddy

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Re: Sea Ice Extent around Antarctica
« Reply #1516 on: October 21, 2020, 12:35:54 PM »
Gero, do you have a 365-day average trend graph for the Antarctic? I'd expect that if you do, then it'd probably show a flat trend like the monthly average graphs, but would be interested all the same.

gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1517 on: October 22, 2020, 10:12:23 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,152,051 KM2 as at 21-Oct-2020

- Extent gain on this day 18k, 31 k more than the average gain on this day (of the last 10 years) of 49k,
- Extent gain from minimum on this date is 0.71 million km2, 0.86 million km2, -(15.3%) less than the 10 year average of -0.18 million km2.
- Extent is at position #29 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  978 k MORE than 2016
- Extent is  614 k MORE than 2017
- Extent is  713 k MORE than 2018
- Extent is  408 k MORE than 2019
- Extent is  279 k MORE than the 1980's Average

- On average 5.4% of ice gain from minimum to maximum done, and 123 days to maximum

Projections. (Table JAXA-Ant1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 3.00 million km2, 0.86 million km2 above the 2017 record low maximum of 18.06 million km2.
___________________________________________________________
N.B. Click on image  for full-size
___________________________________________________________
Blurb during Melting Season
JAXA ANTARCTIC SEA ICE EXTENT:  18,152,051 KM2 as at 21-Oct-2020

- Extent loss on this day 18k, 31 k less than the average loss on this day (of the last 10 years) of 49k,
- Extent loss from maximum on this date is 0.71 million km2, 0.15 million km2, (18%) less than the 10 year average of 0.86 million km2.
- Extent is at position #29 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  978 k MORE than 2016
- Extent is  614 k MORE than 2017
- Extent is  713 k MORE than 2018
- Extent is  408 k MORE than 2019
- Extent is  279 k MORE than the 1980's Average

- On average 5.4% of ice loss  from maximum to minimum done, and 123 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 3.00 million km2, 0.86 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
N.B. Click on image  for full-size
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1518 on: October 22, 2020, 10:35:51 AM »
Gero, do you have a 365-day average trend graph for the Antarctic? I'd expect that if you do, then it'd probably show a flat trend like the monthly average graphs, but would be interested all the same.
Yes

Flat it is not.
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Re: Sea Ice Extent around Antarctica
« Reply #1519 on: October 23, 2020, 12:21:38 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,169,884 KM2 as at 22-Oct-2020

- Extent GAIN on this day 18k, 63 k less than the average LOSS on this day (of the last 10 years) of 45k,
- Extent loss from maximum on this date is 0.69 million km2, 0.21 million km2, (24%) less than the 10 year average of 0.91 million km2.
- Extent is at position #32 in the satellite record of which 18 lower values are in the years before 2000
- Extent is  1,064 k MORE than 2016
- Extent is  661 k MORE than 2017
- Extent is  819 k MORE than 2018
- Extent is  452 k MORE than 2019
- Extent is  335 k MORE than the 1980's Average

- On average 5.7% of ice loss  from maximum to minimum done, and 122 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 3.07 million km2, 0.92 million km2 above the 2017 record low minimum of 2.15 million km2.
________________________________________________
Daily Antarctic sea ice extent losses change from being very low to reversing into a sea ice extent gain on this day. As a result total extent drops from 29th lowest to 32nd lowest
___________________________________________________________
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"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1520 on: October 24, 2020, 10:25:50 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,158,062 KM2 as at 23-Oct-2020

- Extent loss on this day 12k, 47 k less than the average loss on this day (of the last 10 years) of 59k,
- Extent loss from maximum on this date is 0.70 million km2, 0.26 million km2, (27%) less than the 10 year average of 0.96 million km2.
- Extent is at position #34 in the satellite record of which 19 lower values are in the years before 2000
- Extent is  1,141 k MORE than 2016
- Extent is  683 k MORE than 2017
- Extent is  884 k MORE than 2018
- Extent is  530 k MORE than 2019
- Extent is  367 k MORE than the 1980's Average

- On average 6.0% of ice loss  from maximum to minimum done, and 121 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 3.12 million km2, 0.97 million km2 above the 2017 record low minimum of 2.15 million km2.
_____________________________________________________
This very low sea ice extent loss has changed total extent in the last 3 days from 29th to 34th lowest, or 9th highest, in the 42 year satellite record.
___________________________________________________________
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"Para a Causa do Povo a Luta Continua!"
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Hefaistos

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Re: Sea Ice Extent around Antarctica
« Reply #1521 on: October 24, 2020, 11:44:30 AM »

_____________________________________________________
This very low sea ice extent loss has changed total extent in the last 3 days from 29th to 34th lowest, or 9th highest, in the 42 year satellite record.


We have had a slight cooling trend in the Antarctica region (60S-90S) for the last 40 years,
as seen in attached graph. The temperature anomaly trend since 1979 is -0.002C per month, -0.023C per year, or -0.69C per 30 years. Data from CFSR.

Thus we shouldn't be too surprised that sea ice extent keeps a corresponding position in the table. (Presumably, bottom melt doesn't affect sea ice extent too much?)

Interestingly, global warming comes with some exceptions.

gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1522 on: October 24, 2020, 12:26:44 PM »
Quoting the temperature data for 60 to 90 degrees South can be misleading when using it to comment on Antarctic sea ice.

The area of 60 to 90 South is about 34 million km2.
The area of the Antarctic Continent is about 14 million km2, with coastal temperatures averaging about -10 celsius, and at high elevations of the interior averaging at around -60 celsius. The 60 to 90 average temperatures are thus dominated by the continental temperatures. The climate of the surrounding ocean is thus vastly different from the continental climate.

This is even more pronounced at this time of year, when the sea ice edge is between 55 and 65 degrees south. Here it is the Antarctic Circumpolar Current that is important.
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Re: Sea Ice Extent around Antarctica
« Reply #1523 on: October 24, 2020, 03:53:55 PM »
Gero, do you have a 365-day average trend graph for the Antarctic? I'd expect that if you do, then it'd probably show a flat trend like the monthly average graphs, but would be interested all the same.
Yes

Flat it is not.

"Flat" is not the word for anything but the linear trend so far, true.  Thank you for sharing that!

Hefaistos

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Re: Sea Ice Extent around Antarctica
« Reply #1524 on: October 25, 2020, 01:58:27 AM »
Quoting the temperature data for 60 to 90 degrees South can be misleading when using it to comment on Antarctic sea ice.

The area of 60 to 90 South is about 34 million km2.
The area of the Antarctic Continent is about 14 million km2, with coastal temperatures averaging about -10 celsius, and at high elevations of the interior averaging at around -60 celsius. The 60 to 90 average temperatures are thus dominated by the continental temperatures. The climate of the surrounding ocean is thus vastly different from the continental climate.

This is even more pronounced at this time of year, when the sea ice edge is between 55 and 65 degrees south. Here it is the Antarctic Circumpolar Current that is important.

I made another plot, now for the sector closest to the Antarctic coast, from 60S to 70S. Thus excluding the Antarctic land mass.
The trend is the same, pronounced cooling over 40 years.

interstitial

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Re: Sea Ice Extent around Antarctica
« Reply #1525 on: October 25, 2020, 09:09:15 AM »
overall the ocean is warmer but the amount of fresh cold surface water is increasing due to increasing glacier melt. There was a paper about it someone posted on this forum a while back. The water below the surface is much warmer. Whenever it gets stirred up it melts surface ice and the ocean is exposed even in winter. It doesn't look like it is still increasing it looks more like it has leveled off to me. Though it will be another decade before its clear if it is leveling off. Its why antarctic ice extent has been expanding while arctic ice is decreasing. It may eventually lead to more ice around greenland though that is far from certain.

gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1526 on: October 25, 2020, 09:44:47 AM »

I made another plot, now for the sector closest to the Antarctic coast, from 60S to 70S. Thus excluding the Antarctic land mass.
The trend is the same, pronounced cooling over 40 years.

And when you add the post by interstitial you start to see a more complete story of maybe why the sea ice average is barely changed over the last 40 years but warmer ocean water is attacking  ice shelves and glaciers, to a considerable extent from underneath.

I wonder what a 50 to 60 South graph would look like.

meanwhile...
JAXA ANTARCTIC SEA ICE EXTENT:  18,156,720 KM2 as at 24-Oct-2020

- Extent loss on this day 1k, 63 k less than the average loss on this day (of the last 10 years) of 64k,
- Extent loss from maximum on this date is 0.70 million km2, 0.31 million km2, (30%) less than the 10 year average of 1.01 million km2.
- Extent is at position #34 in the satellite record of which 19 lower values are in the years before 2000
- Extent is  1,232 k MORE than 2016
- Extent is  658 k MORE than 2017
- Extent is  967 k MORE than 2018
- Extent is  600 k MORE than 2019
- Extent is  417 k MORE than the 1980's Average

- On average 6.3% of ice loss  from maximum to minimum done, and 120 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 3.18 million km2, 1.03 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________
Antarctic sea ice melt has currently stalled.
___________________________________________________________
N.B. Click on image  for full-size
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

KiwiGriff

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Re: Sea Ice Extent around Antarctica
« Reply #1527 on: October 25, 2020, 11:53:35 PM »
 Southern Ocean Warming
Jean-Baptiste Sallée
Published Online: August 15, 2018
ABSTRACT
Quote
The Southern Ocean plays a fundamental role in global climate. With no continental barriers, it distributes climate signals among the Pacific, Atlantic, and Indian Oceans through its fast-flowing, energetic, and deep-reaching dominant current, the Antarctic Circumpolar Current. The unusual dynamics of this current, in conjunction with energetic atmospheric and ice conditions, make the Southern Ocean a key region for connecting the surface ocean with the world ocean’s deep seas. Recent examinations of global ocean temperature show that the Southern Ocean plays a major role in global ocean heat uptake and storage. Since 2006, an estimated 60%–90% of global ocean heat content change associated with global warming is based in the Southern Ocean. But the warming of its water masses is inhomogeneous. While the upper 1,000 m of the Southern Ocean within and north of the Antarctic Circumpolar Current are warming rapidly, at a rate of 0.1°–0.2°C per decade, the surface sub­polar seas south of this region are not warming or are slightly cooling. However, subpolar abyssal waters are warming at a substantial rate of ~0.05°C per decade due to the formation of bottom waters on the Antarctic continental shelves. Although the processes at play in this warming and their regional distribution are beginning to become clear, the specific mechanisms associated with wind change, eddy activity, and ocean-ice interaction remain areas of active research, and substantial challenges persist to representing them accurately in climate models.

We live in a 3d world.

Animals can be driven crazy by placing too many in too small a pen. Homo sapiens is the only animal that voluntarily does this to himself.
Notebooks of Lazarus Long.
Robert Heinlein.

gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1528 on: October 27, 2020, 12:26:05 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,037,921 KM2 as at 26-Oct-2020

- Extent loss on this day 51k, 0 k more than the average loss on this day (of the last 10 years) of 51k,
- Extent loss from maximum on this date is 0.82 million km2, 0.28 million km2, (25%) less than the 10 year average of 1.10 million km2.
- Extent is at position #34 in the satellite record of which 19 lower values are in the years before 2000
- Extent is  1,273 k MORE than 2016
- Extent is  517 k MORE than 2017
- Extent is  952 k MORE than 2018
- Extent is  676 k MORE than 2019
- Extent is  407 k MORE than the 1980's Average

- On average 6.9% of ice loss  from maximum to minimum done, and 118 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 3.17 million km2, 1.03 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
N.B. Click on image  for full-size
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1529 on: October 28, 2020, 10:59:51 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  17,965,932 KM2 as at 27-Oct-2020

- Extent loss on this day 72k, 20 k more than the average loss on this day (of the last 10 years) of 52k,
- Extent loss from maximum on this date is 0.90 million km2, 0.27 million km2, (23%) less than the 10 year average of 1.16 million km2.
- Extent is at position #34 in the satellite record of which 19 lower values are in the years before 2000
- Extent is  1,258 k MORE than 2016
- Extent is  516 k MORE than 2017
- Extent is  911 k MORE than 2018
- Extent is  672 k MORE than 2019
- Extent is  395 k MORE than the 1980's Average

- On average 7.3% of ice loss  from maximum to minimum done, and 117 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 3.15 million km2, 1.01 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
N.B. Click on image  for full-size
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1530 on: October 29, 2020, 03:23:49 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  17,938,859 KM2 as at 28-Oct-2020

- Extent loss on this day 27k, 50 k less than the average loss on this day (of the last 10 years) of 77k,
- Extent loss from maximum on this date is 0.92 million km2, 0.31 million km2, (25%) less than the 10 year average of 1.23 million km2.
- Extent is at position #36 in the satellite record of which 19 lower values are in the years before 2000
- Extent is  1,316 k MORE than 2016
- Extent is  575 k MORE than 2017
- Extent is  931 k MORE than 2018
- Extent is  726 k MORE than 2019
- Extent is  433 k MORE than the 1980's Average

- On average 7.7% of ice loss  from maximum to minimum done, and 116 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 3.20 million km2, 1.06 million km2 above the 2017 record low minimum of 2.15 million km2.
________________________________________
The very low extent loss on this day moved extent from 34th to 36th lowest - and 36th lowest is also 7th HIGHEST in the satellite record.
___________________________________________________________
N.B. Click on image  for full-size
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1531 on: October 30, 2020, 10:39:03 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  17,914,565 KM2 as at 29-Oct-2020

- Extent loss on this day 24k, 53 k less than the average loss on this day (of the last 10 years) of 77k,
- Extent loss from maximum on this date is 0.95 million km2, 0.36 million km2, (27%) less than the 10 year average of 1.30 million km2.
- Extent is at position #37 in the satellite record of which 19 lower values are in the years before 2000

- Extent is  1,344 k MORE than 2016
- Extent is  645 k MORE than 2017
- Extent is  958 k MORE than 2018
- Extent is  806 k MORE than 2019
- Extent is  482 k MORE than the 1980's Average

- On average 8.2% of ice loss  from maximum to minimum done, and 115 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 3.26 million km2, 1.11 million km2 above the 2017 record low minimum of 2.15 million km2.
____________________________________
Another very low extent loss on this day moved extent from 36th to 37th lowest - which is also 6th HIGHEST in the satellite record.
___________________________________________________________
N.B. Click on image  for full-size
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)