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Author Topic: Antarctic Sea Ice Extent and Area  (Read 979693 times)

blumenkraft

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Re: Sea Ice Extent around Antarctica
« Reply #1450 on: August 01, 2020, 04:40:45 PM »
Another red month added.

Click to enlarge.

Tor Bejnar

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Re: Sea Ice Extent around Antarctica
« Reply #1451 on: August 01, 2020, 06:49:10 PM »
Well, orange.
Arctic ice is healthy for children and other living things because "we cannot negotiate with the melting point of ice"

Stephan

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Re: Sea Ice Extent around Antarctica
« Reply #1452 on: August 10, 2020, 10:34:40 PM »
JAXA Antarctic Sea Ice Extent as of Aug. 09.
The top ten list, all values in M km²
1986  16.56
2002  16.58
2017  16.73
1983  16.88
2018  17.03
1993  17.08
2017  17.11
1989  17.18
2020  17.20
1997  17.22

2020 today is #9 and had recently higher than average increases (+0.08, +0.20 and +0.11 M km² per day) and was #4 in the ranking list on Aug. 06, 2020.

The average of the decades, all values in M km²
1980s 17.38
1990s 17.50
2000s 17.60
2010s 17.61
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ArcTickTock

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Re: Sea Ice Extent around Antarctica
« Reply #1453 on: August 14, 2020, 06:00:02 AM »
I sorta follow Antarctic sea ice, maybe I just never paid enough attention before, am used to seeing a strip of open water at the edge of the Ross IS near the maximum in recent years, but there seem to be a lot of little open pockets along the coast, more than I recall from prior years???

charles_oil

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Re: Sea Ice Extent around Antarctica
« Reply #1454 on: August 14, 2020, 11:17:02 AM »
Thanks for figs Stephan - but "top ten" list = actually the bottom ten I imagine ? 


Stephan

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Re: Sea Ice Extent around Antarctica
« Reply #1455 on: August 14, 2020, 05:50:17 PM »
Yeah. The top ten list is the lowest top ten - as it is common for the Arctic Sea Ice.

JAXA Antarctic Sea Ice extent as of Aug 13, 2020. All values in M km²
2002: 16.82
2017: 16.87
1983: 16.98
1986: 17.01
2018: 17.09
2019: 17.24
1993: 17.28
2003: 17.32
1990: 17.37 (extrapolated)
1989: 17.38
2001: 17.40
2007: 17.41
2015: 17.47
2020: 17.55 (# 14 in the list after massive gains in the last days)

The decadal averages are
1980s ave: 17.57
1990s ave: 17.69
2000s ave: 17.75
2010s ave: 17.78



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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1456 on: August 15, 2020, 02:30:36 PM »
While I was out of action, things changed a lot.....

JAXA ANTARCTIC SEA ICE EXTENT:  17,651,839 KM2 as at 14-Aug-2020


- Extent gain on this day 100k, 40 k more than the average gain on this day (of the last 10 years) of 60k,
- Extent gain from minimum on this date is 14.89 million km2, 0.09 million km2, (0.6%) less than the 10 year average of 14.99 million km2.
- Extent is at position #17 in the satellite record of which 8 lower values are in the years before 2000. On July 31 Antarctic sea ice extent was 7th lowest in the satellite record.
- Extent is  114 k LESS than 2016
- Extent is  697 k MORE than 2017
- Extent is  484 k MORE than 2018
- Extent is  363 k MORE than 2019
- Extent is  9 k MORE than the 1980's Average

- On average 93.8% of ice gain from minimum to maximum done, and 37 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.64 million km2, 0.58 million km2 above the 2017 record low maximum of 18.06 million km2.
____________________________________________
In the 2019-20 Austral Summer Antarctic Mass Loss was very high - from calving, and perhaps more importantly for sea ice extent, from submarine melting of ice shelves and marine terminating glaciers and from unprecedented surface melt runoff. The scientists tell us that this "freshwater hosing" is likely to increase sea ice extent (a surface layer of cold fresh water spreading out from Antarctica will freeze at a higher temperature than saltwater).

On the other hand, farther north the circumpolar winds are increasing and thus tending moving south, while AGW continues. So from the South a tendency for increased sea ice extent while from the North increased warmth of air and ocean.

Which will prevail? At the moment this year it looks like sea ice increase.

___________________________________________________________
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1457 on: August 18, 2020, 12:19:32 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  17,670,119 KM2 as at 17-Aug-2020

- Extent gain on this day 25k, 6 k less than the average gain on this day (of the last 10 years) of 31k,
- Extent gain from minimum on this date is 14.91 million km2, 0.16 million km2, (1.1%) less than the 10 year average of 15.07 million km2.
- Extent is at position #15 in the satellite record of which 6 lower values are in the years before 2000
- Extent is  337 k LESS than 2016
- Extent is  545 k MORE than 2017
- Extent is  289 k MORE than 2018
- Extent is  275 k MORE than 2019
- Extent is  102 k LESS than the 1980's Average

- On average 94.3% of ice gain from minimum to maximum done, and 34 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.57 million km2, 0.51 million km2 above the 2017 record low maximum of 18.06 million km2.
___________________________________________________________
N.B. Click an image once for full-size
« Last Edit: August 18, 2020, 12:25:53 PM by gerontocrat »
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1458 on: August 18, 2020, 12:58:30 PM »
I've given up looking for a trend in either an increase or decrease in Antarctic sea ice extent. I attach March & September monthly average graphs. The R2 value of the linear trend is pretty much zero.

The 365 day average graph is also somewhat unstable.

There does seem to be a trend, and that is towards greater instability - the highs are higher and the lows are lower. But then they do say the circumpolar winds are getting stronger.

My speculation that belongs to me is that the Antarctic is in transition mode - & where that is going to end up is ? ? ? ?
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1459 on: August 20, 2020, 11:57:30 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  17,830,124 KM2 as at 19-Aug-2020

- Extent gain on this day 57k, 44 k more than the average gain on this day (of the last 10 years) of 13k,
- Extent gain from minimum on this date is 15.07 million km2, 0.04 million km2, (0.3%) less than the 10 year average of 15.11 million km2.
- Extent is at position #19 in the satellite record of which 9 lower values are in the years before 2000
- Extent is  276 k LESS than 2016
- Extent is  659 k MORE than 2017
- Extent is  325 k MORE than 2018
- Extent is  391 k MORE than 2019
- Extent is  16 k LESS than the 1980's Average

- On average 94.6% of ice gain from minimum to maximum done, and 32 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.69 million km2, 0.63 million km2 above the 2017 record low maximum of 18.06 million km2.
______________________________________________________
August so far has seen mostly well above average ice extent increases, extent being 7th lowest in the satellite record on August 1st and 19th lowest on the 19th August. (No, not a typo - a small coincidence)
___________________________________________________________
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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 #1460 on: August 20, 2020, 12:19:35 PM »
Antarctic Sea Ice Extent Unpredictability

The plume of the projected sea ice extent by early October using daily changes in sea ice extent over the last ten years are in a range of nearly 2 million km2. Projections of outcomes range from a drop of 0.5 million KM2 to a gain of nearly 1.5 million KM2.

The Antarctic is still very much the realm of the unknown.
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Tor Bejnar

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Re: Sea Ice Extent around Antarctica
« Reply #1461 on: August 20, 2020, 05:11:14 PM »
I guess I'm into adjusting 'quotes' today:
"The Antarctic is still very much the realm of the unknown chaos."
Arctic ice is healthy for children and other living things because "we cannot negotiate with the melting point of ice"

gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1462 on: August 22, 2020, 12:27:02 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  17,919,941 KM2 as at 21-Aug-2020

- Extent gain on this day 24k, 21 k less than the average gain on this day (of the last 10 years) of 45k,
- Extent gain from minimum on this date is 15.16 million km2, 0.03 million km2, (0.2%) less than the 10 year average of 15.19 million km2.
- Extent is at position #20 in the satellite record of which 10 lower values are in the years before 2000
- Extent is  266 k LESS than 2016
- Extent is  546 k MORE than 2017
- Extent is  429 k MORE than 2018
- Extent is  382 k MORE than 2019
- Extent is  8 k LESS than the 1980's Average

- On average 95.1% of ice gain from minimum to maximum done, and 30 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.71 million km2, 0.65 million km2 above the 2017 record low maximum of 18.06 million km2.
___________________________________________________________
N.B. Click an image once 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 #1463 on: August 23, 2020, 12:55:07 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  17,935,765 KM2 as at 22-Aug-2020

- Extent gain on this day 16k, 40 k less than the average gain on this day (of the last 10 years) of 56k,
- Extent gain from minimum on this date is 15.18 million km2, 0.07 million km2, (0.5%) less than the 10 year average of 15.25 million km2.
- Extent is at position #20 in the satellite record of which 9 lower values are in the years before 2000
- Extent is  253 k LESS than 2016
- Extent is  458 k MORE than 2017
- Extent is  410 k MORE than 2018
- Extent is  377 k MORE than 2019
- Extent is  29 k LESS than the 1980's Average

- On average 95.4% of ice gain from minimum to maximum done, and 29 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.67 million km2, 0.61 million km2 above the 2017 record low maximum of 18.06 million km2.
_________________________________________
2 days in a row of below average extent losses - almost counts as an event..
___________________________________________________________
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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 #1464 on: August 25, 2020, 01:03:48 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,105,354 KM2 as at 24-Aug-2020

- Extent gain on this day 123k, 109 k more than the average gain on this day (of the last 10 years) of 14k,
- Extent gain from minimum on this date is 15.35 million km2, -0.04 million km2, -(0.3%) more than the 10 year average of 15.30 million km2.
- Extent is at position #24 in the satellite record of which 12 lower values are in the years before 2000
- Extent is  20 k LESS than 2016
- Extent is  509 k MORE than 2017
- Extent is  460 k MORE than 2018
- Extent is  368 k MORE than 2019
- Extent is  86 k MORE than the 1980's Average

- On average 95.8% of ice gain from minimum to maximum done, and 27 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.78 million km2, 0.72 million km2 above the 2017 record low maximum of 18.06 million km2.
___________________________________________________________
N.B. Click an image once 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 #1465 on: August 25, 2020, 01:14:32 PM »
JAXA Antarctic data - some more...

In the last 2 days extent has changed from 20th lowest to 24th lowest in the satellite record for the day.

ANT- Maxima.
- Extent on this day already above the maximum in 2002** and 2017.
- If high extent losses continue at this rate , I will have to add the years 1979 to 1999 to make the table meaningful.

Ant-Plume. The range of outcomes is large as is the date of the maximum in the last 10 years.
_________________________________________
**2002
There are large gaps in the JAXA and NSIDC record of daily extent in 2002.
The data that is there seems totally out of sync with the surrounding years.
BUT - that is the data in the official record.
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1466 on: August 27, 2020, 11:31:50 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,183,818 KM2 as at 26-Aug-2020

- Extent gain on this day 48k, 17 k more than the average gain on this day (of the last 10 years) of 31k,
- Extent gain from minimum on this date is 15.42 million km2, -0.05 million km2, -(0.3%) more than the 10 year average of 15.37 million km2.
- Extent is at position #25 in the satellite record of which 13 lower values are in the years before 2000
- Extent is  191 k LESS than 2016
- Extent is  569 k MORE than 2017
- Extent is  409 k MORE than 2018
- Extent is  308 k MORE than 2019
- Extent is  85 k MORE than the 1980's Average

- On average 96.2% of ice gain from minimum to maximum done, and 25 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.79 million km2, 0.73 million km2 above the 2017 record low maximum of 18.06 million km2.
______________________________________________________
On the 6th August Antarctic sea ice extent was 4th lowest in the satellite record.
It is now 25th lowest.
And the scientists can theorise about what is going on down there, but always with a caveat of great uncertainty.

___________________________________________________________
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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 #1467 on: August 29, 2020, 10:45:04 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,355,284 KM2 as at 28-Aug-2020

- Extent gain on this day 74k, 44 k more than the average gain on this day (of the last 10 years) of 30k,
- Extent gain from minimum on this date is 15.60 million km2, -0.17 million km2, -(1.1%) more than the 10 year average of 15.43 million km2.
- Extent is at position #31 in the satellite record of which 18 lower values are in the years before 2000
- Extent is  113 k LESS than 2016
- Extent is  841 k MORE than 2017
- Extent is  652 k MORE than 2018
- Extent is  453 k MORE than 2019
- Extent is  188 k MORE than the 1980's Average

- On average 96.6% of ice gain from minimum to maximum done, and 23 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.91 million km2, 0.85 million km2 above the 2017 record low maximum of 18.06 million km2.
_____________________________________________________
On the 6th August Antarctic sea ice extent was 4th lowest in the satellite record.
It is now 31st lowest, or perhsps it is better to say 10th highest

___________________________________________________________
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1468 on: August 31, 2020, 10:46:08 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,463,611 KM2 as at 30-Aug-2020

- Extent gain on this day 38k, 8 k more than the average gain on this day (of the last 10 years) of 30k,
- Extent gain from minimum on this date is 15.70 million km2, -0.21 million km2, -(1.4%) more than the 10 year average of 15.49 million km2.
- Extent is at position #31 in the satellite record of which 18 lower values are in the years before 2000
- Extent is  9 k LESS than 2016
- Extent is  936 k MORE than 2017
- Extent is  697 k MORE than 2018
- Extent is  509 k MORE than 2019
- Extent is  250 k MORE than the 1980's Average

- On average 97.0% of ice gain from minimum to maximum done, and 21 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.95 million km2, 0.89 million km2 above the 2017 record low maximum of 18.06 million km2.
___________________________________________________________
N.B. Click an image once 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 #1469 on: September 01, 2020, 01:00:58 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,422,127 KM2 as at 31-Aug-2020

- Extent LOSS on this day 41k, 35 k  MORE than the unusual average LOSS on this day (of the last 10 years) of 6k,
- Extent gain from minimum on this date is 15.66 million km2, 0.17 million km2, (1.1%) more than the 10 year average of 15.49 million km2.
- Extent is at position #31 in the satellite record of which 18 lower values are in the years before 2000
- Extent is  65 k MORE than 2016
- Extent is  860 k MORE than 2017
- Extent is  693 k MORE than 2018
- Extent is  459 k MORE than 2019
- Extent is  181 k MORE than the 1980's Average

- On average 96.9% of ice gain from minimum to maximum done, and 20 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.91 million km2, 0.85 million km2 above the 2017 record low maximum of 18.06 million km2.
___________________________________________________________
N.B. Click an image once 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 #1470 on: September 01, 2020, 01:15:46 PM »
JAXA Antarctic Sea Ice Extent - a bit more.


I attach the August Monthly Average graph. 2020 continues the ramblings around a trend that does not really exist.

The Plume attached shows that from now the interest starts to switch to 2016, which is why I attach a copy of the daily changes graph with 2016 added.
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1471 on: September 02, 2020, 09:44:13 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,368,240 KM2 as at 01-Sep-2020

- Extent LOSS on this day 54k, 59 k less than the average gain on this day (of the last 10 years) of 5k,
- Extent gain from minimum on this date is 15.61 million km2, 0.12 million km2, (0.7%) more than the 10 year average of 15.49 million km2.
- Extent is at position #24 in the satellite record of which 13 lower values are in the years before 2000
- Extent is  89 k MORE than 2016
- Extent is  854 k MORE than 2017
- Extent is  692 k MORE than 2018
- Extent is  324 k MORE than 2019
- Extent is  100 k MORE than the 1980's Average

- On average 97.0% of ice gain from minimum to maximum done, and 19 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.85 million km2, 0.79 million km2 above the 2017 record low maximum of 18.06 million km2.
______________________________________________________
A second day of extent loss dropped extent from 31st to 24th lowest in the satellite record.
___________________________________________________________
N.B. Click an image once 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 #1472 on: September 03, 2020, 11:04:24 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,327,205 KM2 as at 02-Sep-2020

- Extent LOSS on this day 41k, 60 k less than the average gain on this day (of the last 10 years) of 19k,
- Extent gain from minimum on this date is 15.57 million km2, 0.06 million km2, (0.4%) more than the 10 year average of 15.51 million km2.
- Extent is at position #20 in the satellite record of which 9 lower values are in the years before 2000
- Extent is  138 k MORE than 2016
- Extent is  870 k MORE than 2017
- Extent is  618 k MORE than 2018
- Extent is  236 k MORE than 2019
- Extent is  42 k MORE than the 1980's Average

- On average 97.1% of ice gain from minimum to maximum done, and 18 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.79 million km2, 0.73 million km2 above the 2017 record low maximum of 18.06 million km2.

A third day of unusual extent loss. Extent dropped from 31st to 20th lowest in the satellite record  in two days.

___________________________________________________________
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1473 on: September 10, 2020, 11:21:54 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,597,348 KM2 as at 09-Sep-2020

- Extent gain on this day 18k, 9 k less than the average gain on this day (of the last 10 years) of 27k,
- Extent gain from minimum on this date is 15.84 million km2, 0.18 million km2, (1.2%) more than the 10 year average of 15.65 million km2.
- Extent is at position #25 in the satellite record of which 13 lower values are in the years before 2000
- Extent is  336 k MORE than 2016
- Extent is  683 k MORE than 2017
- Extent is  974 k MORE than 2018
- Extent is  474 k MORE than 2019
- Extent is  171 k MORE than the 1980's Average

- On average 98.2% of ice gain from minimum to maximum done, and 11 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.89 million km2, 0.83 million km2 above the 2017 record low maximum of 18.06 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 #1474 on: September 12, 2020, 01:53:56 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,727,450 KM2 as at 11-Sep-2020

- Extent gain on this day 82k, 68 k more than the average gain on this day (of the last 10 years) of 14k,
- Extent gain from minimum on this date is 15.97 million km2, 0.28 million km2, (1.8%) more than the 10 year average of 15.69 million km2.
- Extent is at position #30 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  662 k MORE than 2016
- Extent is  722 k MORE than 2017
- Extent is  1,158 k MORE than 2018
- Extent is  578 k MORE than 2019
- Extent is  241 k MORE than the 1980's Average

- On average 98.5% of ice gain from minimum to maximum done, and 10 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.97 million km2, 0.91 million km2 above the 2017 record low maximum of 18.06 million km2.
___________________________________________________________
N.B. Click on image for full-size
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Re: Sea Ice Extent around Antarctica
« Reply #1475 on: September 14, 2020, 01:24:30 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,789,715 KM2 as at 13-Sep-2020

- Extent gain on this day 34k, 28 k more than the average gain on this day (of the last 10 years) of 6k,
- Extent gain from minimum on this date is 16.03 million km2, 0.32 million km2, (2.0%) more than the 10 year average of 15.71 million km2.
- Extent is at position #31 in the satellite record of which 17 lower values are in the years before 2000
- Extent is  975 k MORE than 2016
- Extent is  762 k MORE than 2017
- Extent is  1,266 k MORE than 2018
- Extent is  618 k MORE than 2019
- Extent is  253 k MORE than the 1980's Average

- On average 98.8% of ice gain from minimum to maximum done, and 8 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.98 million km2, 0.92 million km2 above the 2017 record low maximum of 18.06 million km2.
___________________________________________________________
N.B. Click on image  for full-size
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Re: Sea Ice Extent around Antarctica
« Reply #1476 on: September 15, 2020, 03:25:32 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,848,016 KM2 as at 14-Sep-2020

- Extent gain on this day 58k, 59 k more than the average gain on this day (of the last 10 years) of 1k,
- Extent gain from minimum on this date is 16.09 million km2, 0.38 million km2, (2.4%) more than the 10 year average of 15.71 million km2.
- Extent is at position #33 in the satellite record of which 17 lower values are in the years before 2000
- Extent is  1,085 k MORE than 2016
- Extent is  880 k MORE than 2017
- Extent is  1,301 k MORE than 2018
- Extent is  654 k MORE than 2019
- Extent is  296 k MORE than the 1980's Average

- On average 98.9% of ice gain from minimum to maximum done, and 7 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 19.03 million km2, 0.97 million km2 above the 2017 record low maximum of 18.06 million km2.
___________________________________________________________
N.B. Click on image  for full-size
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oren

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Re: Sea Ice Extent around Antarctica
« Reply #1477 on: September 15, 2020, 05:07:07 PM »
Quote
Extent is at position #33 in the satellite record
Out of how many? How far to number 1 from above?

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Re: Sea Ice Extent around Antarctica
« Reply #1478 on: September 15, 2020, 07:21:08 PM »
It should be 42 years (1979 to 2020).
It is too late just to be concerned about Climate Change

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Re: Sea Ice Extent around Antarctica
« Reply #1479 on: September 16, 2020, 12:38:59 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,861,031 KM2 as at 15-Sep-2020

- Extent gain on this day 13k, 0 k less than the average gain on this day (of the last 10 years) of 13k,
- Extent gain from minimum on this date is 16.10 million km2, 0.38 million km2, (2.4%) more than the 10 year average of 15.72 million km2.
- Extent is at position #33 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  1,097 k MORE than 2016
- Extent is  933 k MORE than 2017
- Extent is  1,237 k MORE than 2018
- Extent is  618 k MORE than 2019
- Extent is  289 k MORE than the 1980's Average

- On average 99.0% of ice gain from minimum to maximum done, and 7 days to maximum

Projections. (Table JAXA-Arc1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 19.02 million km2, 0.96 million km2 above the 2017 record low maximum of 18.06 million km2.
___________________________________________________
It looks like the September monthly average graph will show that the Antarctic Sea Ice has completely recovered from the massive losses that started after the record maximum in 2014.
___________________________________________________________
N.B. Click on image  for full-size
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Re: Sea Ice Extent around Antarctica
« Reply #1480 on: September 16, 2020, 12:42:25 PM »
It should be 42 years (1979 to 2020).
Which it is...

Attached is the table comparing the current extent value with all 41 previous yeas' maxima. I wonder how far down the table 2020 will go.
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Re: Sea Ice Extent around Antarctica
« Reply #1481 on: September 18, 2020, 10:21:33 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,766,938 KM2 as at 17-Sep-2020

- Extent LOSS on this day 52k, 58 k less than the average gain on this day (of the last 10 years) of 6k,
- Extent gain from minimum on this date is 16.01 million km2, 0.26 million km2, (1.7%) more than the 10 year average of 15.74 million km2.
- Extent is at position #29 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  972 k MORE than 2016
- Extent is  920 k MORE than 2017
- Extent is  948 k MORE than 2018
- Extent is  501 k MORE than 2019
- Extent is  163 k MORE than the 1980's Average

- On average 99.2% of ice gain from minimum to maximum done, and 5 days to maximum

Projections. (Table JAXA-Ant1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.89 million km2, 0.83 million km2 above the 2017 record low maximum of 18.06 million km2.

The last 2 days have seen extent losses totalling 94k. It is possible that the 2020 maximum was reached on the 15th Sept at 18.86 million km2. The projections table may, therefore, be redundant.
___________________________________________________________
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Re: Sea Ice Extent around Antarctica
« Reply #1482 on: September 19, 2020, 01:43:21 PM »
Hey!
Another good topic
I take this opportunity to provide a link to a recent study, which focused on glaciers and their speed, and about the total mass of ice, on the continent .
It is not directly related to the subject, but I find it interesting and I did not find a topic about continental Antarctica ice
Thank you for your contributions
Sorry, excuse my bad english

gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1483 on: September 19, 2020, 02:46:33 PM »
Hey!
Another good topic
I take this opportunity to provide a link to a recent study, which focused on glaciers and their speed, and about the total mass of ice, on the continent .
It is not directly related to the subject, but I find it interesting and I did not find a topic about continental Antarctica ice
Thank you for your contributions
The Antarctic Ice Sheet thread has got loads of stuff about Antarctica, including ice mass, glaciers etc etc
https://forum.arctic-sea-ice.net/index.php/topic,2903.msg227406.html#msg227406
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Re: Sea Ice Extent around Antarctica
« Reply #1484 on: September 20, 2020, 11:43:11 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,756,810 KM2 as at 19-Sep-2020

- Extent LOSS on this day 12k, 2 k less than the average loss on this day (of the last 10 years) of 14k,
- Extent gain from minimum on this date is 16.00 million km2, 0.27 million km2, (1.7%) more than the 10 year average of 15.73 million km2.
- Extent is at position #28 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  869 k MORE than 2016
- Extent is  974 k MORE than 2017
- Extent is  833 k MORE than 2018
- Extent is  618 k MORE than 2019
- Extent is  148 k MORE than the 1980's Average

- On average 99.2% of ice gain from minimum to maximum done, and 4 days to maximum

Projections. (Table JAXA-Ant1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.88 million km2, 0.82 million km2 above the 2017 record low maximum of 18.06 million km2.
______________________________________________
The maximum may, or may not, have already been reached on 15th September at 18.86 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 #1485 on: September 21, 2020, 12:04:37 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,726,530 KM2 as at 20-Sep-2020

- Extent LOSS on this day 30k, 52 k less than the average gain on this day (of the last 10 years) of 22k,
- Extent gain from minimum on this date is 15.97 million km2, 0.21 million km2, (1.4%) more than the 10 year average of 15.75 million km2.
- Extent is at position #27 in the satellite record of which 16 lower values are in the years before 2000
- Extent is  866 k MORE than 2016
- Extent is  980 k MORE than 2017
- Extent is  696 k MORE than 2018
- Extent is  583 k MORE than 2019
- Extent is  131 k MORE than the 1980's Average

- On average 99.4% of ice gain from minimum to maximum done, and 3 days to maximum

Projections. (Table JAXA-Ant1)

Average remaining freeze (of the last 10 years) would produce a maximum in Sept 2020 of 18.86 million km2, 0.80 million km2 above the 2017 record low maximum of 18.06 million km2.
________________________________________________________
Yet another extent loss makes it even more likely that the maximum extent was reached on 15 Sept at 18.86 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 #1486 on: September 21, 2020, 12:09:11 PM »
The graph attached shows how even with current extent 130k lower than the current maximum, it is still too early to call the maximum. The data is just too variable.
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Re: Sea Ice Extent around Antarctica
« Reply #1487 on: September 22, 2020, 10:57:37 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,693,809 KM2 as at 21-Sep-2020

- Extent LOSS on this day 33k, 44 k less than the average gain on this day (of the last 10 years) of 11k,
- Extent gain from minimum on this date is 15.93 million km2, 0.17 million km2, (1.1%) more than the 10 year average of 15.76 million km2.
- Extent is at position #25 in the satellite record of which 14 lower values are in the years before 2000
- Extent is  796 k MORE than 2016
- Extent is  982 k MORE than 2017
- Extent is  604 k MORE than 2018
- Extent is  531 k MORE than 2019
- Extent is  133 k MORE than the 1980's Average

- On average one day beyond the maximum.

Projections. (Table JAXA-Ant1)

It is probable that the maximum was reached at 18.86 million km2, at the fairly early date of 15th September. This is 0.80 million km2 above the 2017 record low maximum of 18.06 million km2.

I expect to start posting projections of the 2021 minimum some time this week.
___________________________________________________________
N.B. Click on image  for full-size
« Last Edit: September 22, 2020, 12:14:15 PM by gerontocrat »
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Re: Sea Ice Extent around Antarctica
« Reply #1488 on: September 23, 2020, 01:18:16 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,714,304 KM2 as at 22-Sep-2020

- Extent gain on this day 20k, 3 k more than the average gain on this day (of the last 10 years) of 17k,
- Extent is at position #25 in the satellite record of which 14 lower values are in the years before 2000
- Extent is  806 k MORE than 2016
- Extent is  1,000 k MORE than 2017
- Extent is  611 k MORE than 2018
- Extent is  537 k MORE than 2019
- Extent is  177 k MORE than the 1980's Average

A blip upwards in extent on this day means not switching to the melting season narrative today. One stays in limbo for a bit longer?
« Last Edit: September 24, 2020, 11:17:02 AM by gerontocrat »
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Re: Sea Ice Extent around Antarctica
« Reply #1489 on: September 24, 2020, 11:16:27 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,789,907 KM2 as at 23-Sep-2020

- Extent gain on this day 76k, 92 k more than the average loss on this day (of the last 10 years) of 16k,
- Extent is at position #30 in the satellite record of which 17 lower values are in the years before 2000
- Extent is  863 k MORE than 2016
- Extent is  1,102 k MORE than 2017
- Extent is  711 k MORE than 2018
- Extent is  584 k MORE than 2019
- Extent is  279 k MORE than the 1980's Average

Another blip upwards in extent, and this time large, on this day means not switching to the melting season narrative today. The current maximum of 18.86 milliom km2 is only 70 k more than extent on this day.  One stays in limbo for a bit longer?

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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1490 on: September 25, 2020, 11:16:59 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,802,524 KM2 as at 24-Sep-2020

- Extent gain on this day 13k, 41 k more than the average loss on this day (of the last 10 years) of 28k,
- Extent is at position #31 in the satellite record of which 18 lower values are in the years before 2000
- Extent is  906 k MORE than 2016
- Extent is  1,195 k MORE than 2017
- Extent is  767 k MORE than 2018
- Extent is  540 k MORE than 2019
- Extent is  315 k MORE than the 1980's Average

Another gain - extent just 60k less than the current maximum of 15 Sept. Still might be a new maximum in the next few days.
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Re: Sea Ice Extent around Antarctica
« Reply #1491 on: September 26, 2020, 01:13:52 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,855,088 KM2 as at 25-Sep-2020

- Extent gain on this day 53k, 60 k more than the average loss on this day (of the last 10 years) of 7k,
- Extent is at position #32 in the satellite record of which 18 lower values are in the years before 2000
- Extent is  965 k MORE than 2016
- Extent is  1,280 k MORE than 2017
- Extent is  836 k MORE than 2018
- Extent is  562 k MORE than 2019
- Extent is  390 k MORE than the 1980's Average

Another large blip upwards in extent on this day means not switching to the melting season narrative today. The current maximum of 18.86 milliom km2 of the 15th September is only 6k km2 more than extent on this day.  One stays in limbo for a bit longer?
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Re: Sea Ice Extent around Antarctica
« Reply #1492 on: September 27, 2020, 11:19:51 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,856,524 KM2 as at 26-Sep-2020

- Extent gain on this day 1k, 18 k less than the average gain on this day (of the last 10 years) of 19k,
- Extent is at position #31 in the satellite record of which 18 lower values are in the years before 2000
- Extent is  939 k MORE than 2016
- Extent is  1,222 k MORE than 2017
- Extent is  844 k MORE than 2018
- Extent is  526 k MORE than 2019
- Extent is  410 k MORE than the 1980's Average

Another blip upwards in extent on this day, but this time just 1k, means not switching to the melting season narrative today. The current maximum of 18.86 milliom km2 of the 15th September is only 5k km2 more than extent on this day.  One stays in limbo for yet another day
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oren

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Re: Sea Ice Extent around Antarctica
« Reply #1493 on: September 27, 2020, 01:14:19 PM »
Will it or won't it...?

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Re: Sea Ice Extent around Antarctica
« Reply #1494 on: September 28, 2020, 12:31:30 PM »
Will it or won't it...?
It won't, extent reduced, so today my post will assume that the maximum of 15th Septemeber of 18.86 million km2 was the maximum. Of course today and the days afterwards may see extent increases.

JAXA ANTARCTIC SEA ICE EXTENT:  18,838,447 KM2 as at 27-Sep-2020

- Extent loss on this day 18k, 39 k less than the average gain on this day (of the last 10 years) of 21k,
- Extent loss from maximum on this date is -0.02 million km2, -0.23 million km2, (91%) less than the 10 year average of 0.26 million km2.
- Extent is at position #30 in the satellite record of which 17 lower values are in the years before 2000
- Extent is  919 k MORE than 2016
- Extent is  1,209 k MORE than 2017
- Extent is  795 k MORE than 2018
- Extent is  491 k MORE than 2019
- Extent is  401 k MORE than the 1980's Average

- On average 1.6% of ice loss  from maximum to minimum done, and 147 days to maximum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.76 million km2, 0.61 million km2 above the 2017 record low minimum of 2.15 million km2.
___________________________________________________________
N.B. Click on image  for full-size
« Last Edit: September 28, 2020, 12:47:00 PM by gerontocrat »
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Re: Sea Ice Extent around Antarctica
« Reply #1495 on: September 29, 2020, 12:53:38 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,806,540 KM2 as at 28-Sep-2020

Extent reduced again on this day, so for another day my post will assume that the maximum of 15th September of 18.86 million km2 was the maximum. Of course today and the days afterwards may see extent increases. (see next post for the plume)

- Extent loss on this day 32k, 44 k less than the average gain on this day (of the last 10 years) of 12k,
- Extent loss from maximum on this date is -0.05 million km2, -0.20 million km2, (78%) less than the 10 year average of 0.25 million km2.
- Extent is at position #30 in the satellite record of which 17 lower values are in the years before 2000
- Extent is  862 k MORE than 2016
- Extent is  1,124 k MORE than 2017
- Extent is  754 k MORE than 2018
- Extent is  497 k MORE than 2019
- Extent is  383 k MORE than the 1980's Average

- On average 1.6% of ice loss  from maximum to minimum done, and 146 days to maximum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 3.02 million km2, 0.87 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 #1496 on: September 29, 2020, 12:59:46 PM »
I attach the plume of forward projections from previous years' daily changes.
It shows the high extent of variation between years.

I also attach the table that compares the 2020 maximum sea ice extent with previous years.
2020 was the 26th lowest in the 42 years satellite record, and the maximum was above each decadal average.
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Re: Sea Ice Extent around Antarctica
« Reply #1497 on: September 30, 2020, 10:05:14 AM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,747,982 KM2 as at 29-Sep-2020

- Extent loss on this day 59k, 65 k less than the average gain on this day (of the last 10 years) of 6k,
- Extent loss from maximum on this date is -0.11 million km2, -0.13 million km2, (54%) less than the 10 year average of 0.25 million km2.
- Extent is at position #30 in the satellite record of which 17 lower values are in the years before 2000
- Extent is  819 k MORE than 2016
- Extent is  1,042 k MORE than 2017
- Extent is  689 k MORE than 2018
- Extent is  435 k MORE than 2019
- Extent is  332 k MORE than the 1980's Average

- On average 1.5% of ice loss  from maximum to minimum done, and 145 days to maximum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.96 million km2, 0.81 million km2 above the 2017 record low minimum of 2.15 million km2.
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Extent on this day is about 110k below the maximum. It loks like the melting season this time may be properly underway after the fairly usual lengthy end of freezing season wobbles,
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N.B. Click on image  for full-size
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1498 on: October 01, 2020, 12:59:41 PM »
JAXA ANTARCTIC SEA ICE EXTENT:  18,718,286 KM2 as at 30-Sep-2020

- Extent loss on this day 30k, 32 k less than the average gain on this day (of the last 10 years) of 2k,
- Extent loss from maximum on this date is -0.14 million km2, -0.11 million km2, (43%) less than the 10 year average of 0.25 million km2.
- Extent is at position #29 in the satellite record of which 17 lower values are in the years before 2000
- Extent is  748 k MORE than 2016
- Extent is  985 k MORE than 2017
- Extent is  608 k MORE than 2018
- Extent is  394 k MORE than 2019
- Extent is  305 k MORE than the 1980's Average

- On average 1.6% of ice loss  from maximum to minimum done, and 144 days to minimum

Projections. (Table JAXA-Ant1)

Average remaining melt (of the last 10 years) would produce a minimum in Feb 2021 of 2.92 million km2, 0.78 million km2 above the 2017 record low minimum of 2.15 million km2.
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N.B. Click on image  for full-size
« Last Edit: October 01, 2020, 08:59:22 PM by gerontocrat »
"Para a Causa do Povo a Luta Continua!"
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gerontocrat

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Re: Sea Ice Extent around Antarctica
« Reply #1499 on: October 01, 2020, 01:13:15 PM »
JAXA Antarctic sea ice data - a bit more

I attach the September Monthly average graph. The obvious story is that after 42 years, average September extent in 2020  is pretty much what it was in 1979, BUT....

- the annual trend is a 2k increase in extent, with an R2 value of less than .005, i.e. the trend is basically meaningless,
-  the real story is the large yearly increase in maximum extent from 2011 to 2014, followed by a crash to a record low maximum extent in 2017, followed by a return to sort of average maximum this year.

I have read various papers about the Antarctic sea ice, but my conclusion is that these large annual changes in sea ice extent are not satisfactorily explained. In other words, to me the real story is one of poorly understood Antarctic instabilty.
"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)