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oren

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Re: Sea Ice Extent around Antarctica
« Reply #350 on: January 28, 2017, 03:31:25 PM »
Interesting and thorough analysis, but summing the different declines to minimum by sea assumes they'll all be at minimum on the same date. And although we'd expect them all to hit minimum around the end of Feb based on previous years, there's also likely to be a fair bit of individual variation
Thanks. Just to clarify, I guesstimated the decline of each sea to a general minimum date, not to its own minimum.

dingojoe

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Re: Sea Ice Extent around Antarctica
« Reply #351 on: January 28, 2017, 07:14:47 PM »
Judging by recent history, the Ross is one of the first areas to start refreezing, and it  restarts around whatever ice is left from melting season, but if there is no ice left then it'll have to start from scratch which may push back and slow the start of refreeze.

Oren may even be too pessimistic about the minimum in the Ross, outside of the far southern part of Mcmurdo bay and a small area of fast ice between Ross and the Amudsen what ice will be left by mid-Feb?

Great analysis overall by Oren.

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Re: Sea Ice Extent around Antarctica
« Reply #352 on: January 28, 2017, 11:10:05 PM »

2017, 01, 25       2726000 sq km
2017, 01, 26       2702000 sq km
2017, 01, 27       2651000 sq km





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Re: Sea Ice Extent around Antarctica
« Reply #353 on: January 29, 2017, 12:53:51 AM »
Thanks. Just to clarify, I guesstimated the decline of each sea to a general minimum date, not to its own minimum.

OK, I may have underestimated the chances of a <2 million minimum based on my own cruder eyeballing of trends by sea. Will be interesting to watch.

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Re: Sea Ice Extent around Antarctica
« Reply #354 on: January 29, 2017, 05:42:25 AM »
For Jan. 28th JAXA has posted 2,554,386 km2 for SIE around Antarctica.

Down by 73,446 km2.

frankendoodle

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Re: Sea Ice Extent around Antarctica
« Reply #355 on: January 29, 2017, 08:36:40 AM »
I applaud everyone's skepticism in regards to SIE bottoming out this season.  But at this point JAXA SIE is 300K from a new record with approx. one month of melt left to go.

Do any of you REALLY THINK we will not hit a record low this year?!

Also, even a severe record low will not be too outside two SD. Antarctica is more about basal continental melt than sea ice. 

oren

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Re: Sea Ice Extent around Antarctica
« Reply #356 on: January 29, 2017, 10:28:29 AM »
Do any of you REALLY THINK we will not hit a record low this year?!
The more common question is how low will it go, as shown by the poll held a few weeks ago.

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Re: Sea Ice Extent around Antarctica
« Reply #357 on: January 29, 2017, 11:10:09 AM »
Yes, there is clearly some kind of momentum going on, given the monotonous decline.

This is a great thread. Thanks for all the info, everyone!
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Re: Sea Ice Extent around Antarctica
« Reply #358 on: January 29, 2017, 11:41:22 AM »
Watchimg the other years show a decline of 3/4 - 1 million of square km from this date to the minimum, rather independent from the overall area. High and low years almost parallel.

Probably the daily melting of ice in all regions is rather kind of a constant. This would bring us way below 2 m of square km

lurkalot

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Re: Sea Ice Extent around Antarctica
« Reply #359 on: January 29, 2017, 12:41:03 PM »
Perhaps someone with access to the numbers could start ticking off the rankings - this year's extent must already be below the minima for most years in the satellite record.

crandles

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Re: Sea Ice Extent around Antarctica
« Reply #360 on: January 29, 2017, 12:45:10 PM »
2.55

390k below previous lowest for day
300k above lowest ever recorded
290k lost in last 4 days

Trends may indicate heading for around 1.8-1.9, but it could still slow down because there is so little ice that is easily melted, or albedo effect putting more heat in surface waters could mean continued decline at steep rate and a late minimum. Worth watch to see which way it goes and why if that can be determined.

crandles

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Re: Sea Ice Extent around Antarctica
« Reply #361 on: January 29, 2017, 12:49:40 PM »
1997 2.25
2011 2.32
1993 2.37
2006 2.41
1980 2.53
1984 2.53
2017 2.55

so 7th I think

Darvince

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Re: Sea Ice Extent around Antarctica
« Reply #362 on: January 29, 2017, 01:25:11 PM »
For Jan. 28th JAXA has posted 2,554,386 km2 for SIE around Antarctica.

Down by 73,446 km2.
this is getting insane

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Re: Sea Ice Extent around Antarctica
« Reply #363 on: January 29, 2017, 01:47:34 PM »
What is remarkable to me about this year's melting season is persistence. At the beginning of September a load of ice disappeared and the melt stayed at record lows month after month. Where were the wobbles?

But my question is : Given four months of record insolation, what has been the effect on SSTs in the region, and are there any models on possible delays to /reductions in refreezing this Austral winter ?
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Re: Sea Ice Extent around Antarctica
« Reply #364 on: January 29, 2017, 02:23:50 PM »
The melting momentum is strong both in Atlantic and Pacific sides. There's enough of weak ice to melt out just in upcoming days. The wind patterns in the Weddel sea compact the ice pack and import additional heat. I don't expect significant slowdown in dropping SIE numbers at least in several days

Wipneus

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Re: Sea Ice Extent around Antarctica
« Reply #365 on: January 29, 2017, 02:29:35 PM »
NSIDC extent sorted:

1997-02-27  2.264152
1993-02-19  2.280783
2011-02-22  2.318847
1984-02-27  2.381731
2006-02-20  2.486597
1992-02-23  2.492393
1980-02-25  2.516067
1991-02-27  2.553553
2016-02-17  2.577755
2017-01-28  2.581008

Overtaking today 2000, 1996, 1985 and 1988's min's, now tenth position.

NSIDC area's position is much further down, not even in the top half at position 26:

1993-02-26  1.248163
1984-02-27  1.509585
1996-02-25  1.535481
2000-02-18  1.561033
2006-03-04  1.565059
1999-02-26  1.577058
1981-03-03  1.588790
1997-02-19  1.589288
1985-02-19  1.635733
1992-02-23  1.641926
1980-02-27  1.646186
2002-02-20  1.649281
1998-02-26  1.650298
2011-02-26  1.677629
1988-02-24  1.691611
1982-02-17  1.713860
2016-02-17  1.729589
1983-02-25  1.738279
1986-02-27  1.763319
1987-02-24  1.781372
2009-02-22  1.794061
1991-02-25  1.797485
2005-02-25  1.798750
2007-02-19  1.821313
1989-02-21  1.841981
2017-01-28  1.923221


Tigertown

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Re: Sea Ice Extent around Antarctica
« Reply #366 on: January 29, 2017, 02:57:28 PM »
A  954 hpa LP system is forecast to set up by late on the 31st just off Weddell Sea in an area of warmer water. It will cause waves in the 4+ m range. Some of the sea ice there near the edge, not being very thick, will either be melted out or weakened enough to melt before the season's end.

lurkalot

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Re: Sea Ice Extent around Antarctica
« Reply #367 on: January 29, 2017, 04:11:15 PM »
Thank you Crandles and Wipneus.

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Re: Sea Ice Extent around Antarctica
« Reply #368 on: January 29, 2017, 04:22:19 PM »
Some info about sea ice, esp. in the Ross sea area.

1st image shows sea ice in 1974 - source NSF

2nd image: map shows actual edge of the ice shelf about 1963 - source - glacier explorer

3rd image shows today's sea ice.  Enhanced and cropped from antarctic mosaic section

Note where sea ice retreated in about 1963 to the calving fronts of the glaciers.
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Re: Sea Ice Extent around Antarctica
« Reply #369 on: January 29, 2017, 06:06:56 PM »
The Leutzow-Holm Bay has melted out three times in the past as I understand it. In the mid sixties, 1980 and 1988. During these retreats of the fast ice in the bay the Shirase Glaciers toe collasped. I'm watching this progress and wondering if this will be deja vu all over again. The toe looks well shattered so a loss of the fast ice will give it loads of room to stretch and relax. On the left side of the open water in the pollyanna there is a large piece of fast ice starting to split off running almost up to the toe. This piece of ice is about 15x45kms which, I think, would give the Shirase some room to start a maneuver? Would the afore mentioned years have any similarities to the SIE this year?

dingojoe

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Re: Sea Ice Extent around Antarctica
« Reply #370 on: January 29, 2017, 07:02:40 PM »
The Leutzow-Holm Bay has melted out three times in the past as I understand it. In the mid sixties, 1980 and 1988. During these retreats of the fast ice in the bay the Shirase Glaciers toe collasped. I'm watching this progress and wondering if this will be deja vu all over again. The toe looks well shattered so a loss of the fast ice will give it loads of room to stretch and relax. On the left side of the open water in the pollyanna there is a large piece of fast ice starting to split off running almost up to the toe. This piece of ice is about 15x45kms which, I think, would give the Shirase some room to start a maneuver? Would the afore mentioned years have any similarities to the SIE this year?

A relevant shot from Worldview

http://go.nasa.gov/2kC8vAJ

Besides the crack Red mentions, there is a faint secondary crack that goes northward towards the outer fast ice edge before curving across to the oddly colored channel Red referenced in the Melt Ice thread.

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Re: Sea Ice Extent around Antarctica
« Reply #371 on: January 29, 2017, 08:20:13 PM »
The Leutzow-Holm Bay has melted out three times in the past as I understand it. In the mid sixties, 1980 and 1988. During these retreats of the fast ice in the bay the Shirase Glaciers toe collasped. I'm watching this progress and wondering if this will be deja vu all over again. The toe looks well shattered so a loss of the fast ice will give it loads of room to stretch and relax. On the left side of the open water in the pollyanna there is a large piece of fast ice starting to split off running almost up to the toe. This piece of ice is about 15x45kms which, I think, would give the Shirase some room to start a maneuver? Would the afore mentioned years have any similarities to the SIE this year?

A relevant shot from Worldview

http://go.nasa.gov/2kC8vAJ

Besides the crack Red mentions, there is a faint secondary crack that goes northward towards the outer fast ice edge before curving across to the oddly colored channel Red referenced in the Melt Ice thread.

Polar view on the 26th.
http://www.polarview.aq/images/105_S1jpgfull/S1B_EW_GRDM_1SSH_20170126T175526_8079_S_1.final.jpg

magnamentis

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Re: Sea Ice Extent around Antarctica
« Reply #372 on: January 29, 2017, 09:15:47 PM »
The Leutzow-Holm Bay has melted out three times in the past as I understand it. In the mid sixties, 1980 and 1988. During these retreats of the fast ice in the bay the Shirase Glaciers toe collasped. I'm watching this progress and wondering if this will be deja vu all over again. The toe looks well shattered so a loss of the fast ice will give it loads of room to stretch and relax. On the left side of the open water in the pollyanna there is a large piece of fast ice starting to split off running almost up to the toe. This piece of ice is about 15x45kms which, I think, would give the Shirase some room to start a maneuver? Would the afore mentioned years have any similarities to the SIE this year?

A relevant shot from Worldview

http://go.nasa.gov/2kC8vAJ

Besides the crack Red mentions, there is a faint secondary crack that goes northward towards the outer fast ice edge before curving across to the oddly colored channel Red referenced in the Melt Ice thread.

Polar view on the 26th.
http://www.polarview.aq/images/105_S1jpgfull/S1B_EW_GRDM_1SSH_20170126T175526_8079_S_1.final.jpg

those ar pics for those who claimed already days ago that there is no more ice to melt LOL

one has to do the math a bit more thoroughly, even that small stripe of ice (landfast ice for example) is many thousands of kilometers in length and that calculated times a few hundred meters or a few kilometers in width makes quite quickly a few hundred thousand km2

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Re: Sea Ice Extent around Antarctica
« Reply #373 on: January 29, 2017, 09:49:35 PM »
The Leutzow-Holm Bay has melted out three times in the past as I understand it. In the mid sixties, 1980 and 1988. During these retreats of the fast ice in the bay the Shirase Glaciers toe collasped. I'm watching this progress and wondering if this will be deja vu all over again. The toe looks well shattered so a loss of the fast ice will give it loads of room to stretch and relax. On the left side of the open water in the pollyanna there is a large piece of fast ice starting to split off running almost up to the toe. This piece of ice is about 15x45kms which, I think, would give the Shirase some room to start a maneuver? Would the afore mentioned years have any similarities to the SIE this year?

A relevant shot from Worldview

http://go.nasa.gov/2kC8vAJ

Besides the crack Red mentions, there is a faint secondary crack that goes northward towards the outer fast ice edge before curving across to the oddly colored channel Red referenced in the Melt Ice thread.

Polar view on the 26th.
http://www.polarview.aq/images/105_S1jpgfull/S1B_EW_GRDM_1SSH_20170126T175526_8079_S_1.final.jpg

those ar pics for those who claimed already days ago that there is no more ice to melt LOL

one has to do the math a bit more thoroughly, even that small stripe of ice (landfast ice for example) is many thousands of kilometers in length and that calculated times a few hundred meters or a few kilometers in width makes quite quickly a few hundred thousand km2
Magna that entire coast of Enderby Land melted out last year from Cape Ann to just east of Leutzow-Holm Bay and the shape it's in this year I would expect it to take the bay with it at present rate. I have no idea about area but it's a wee bit. The whole damn continent is waking up this year. Just nuts.

FredBear

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Re: Sea Ice Extent around Antarctica
« Reply #374 on: January 29, 2017, 11:21:30 PM »
On arctic io you can see bits breaking up all round - some like McMurdo have more ice this year but are now breaking up.
The Weddell sea is the area with the most ice adrift but is there too much to allow significant warming? The ice does retreat from the east side, leaving the Brunt Ice Shelf area relatively free, particularly in earlier years. There is a large piece of ice west of Brunt which looks the same as in 2013!
I wonder if the sea ice in the Amundsen Sea eastwards is broken up enough to follow the example of Ross's sea ice and disappear?
I notice the "small" piece of the PIG which broke off the other day is moving out into clear water.
Lots of water to absorb solar energy, the question is whether there will be enough heat to make much difference to the continent's fringes?

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Re: Sea Ice Extent around Antarctica
« Reply #375 on: January 29, 2017, 11:50:05 PM »
The Low that is getting ready to set up over warmer water near  the Weddell Sea starts out with a twin directly over the ice. The two systems will convey circulation of air between them. After a couple days, one Low will be left over the Sea. One area in particular near the shore will be most affected by waves, until about the 3rd of Feb. when waves will set further offshore and attack another area of ice. Winds will not be terribly strong from these, but will persist over a long time. The Peninsula which usually protects the sea ice, will be on the wrong side of this all. I am not even trying to begin to guess the outcome for the sea ice, but noting the possibility that it could be bad.

Tigertown

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Re: Sea Ice Extent around Antarctica
« Reply #376 on: January 30, 2017, 05:32:36 AM »
For Jan. 29th JAXA has posted 2,504,147 km2 for SIE around Antarctica.

Down by 50,239 km2.

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Re: Sea Ice Extent around Antarctica
« Reply #377 on: January 30, 2017, 02:35:37 PM »
NSIDC extent drops -69k, area -46k.

Extent overtakes 1980, 1991 and 2016, now at pos #7
Area stays at #26

Extent
1 1997-02-27 2.264152
2 1993-02-19 2.280783
3 2011-02-22 2.318847
4 1984-02-27 2.381731
5 2006-02-20 2.486597
6 1992-02-23 2.492393
7 2017-01-29 2.512386
8 1980-02-25 2.516067
9 1991-02-27 2.553553
10 2016-02-17 2.577755
Area
1 1993-02-26 1.248163
2 1984-02-27 1.509585
3 1996-02-25 1.535481
4 2000-02-18 1.561033
5 2006-03-04 1.565059
6 1999-02-26 1.577058
7 1981-03-03 1.588790
8 1997-02-19 1.589288
9 1985-02-19 1.635733
10 1992-02-23 1.641926
11 1980-02-27 1.646186
12 2002-02-20 1.649281
13 1998-02-26 1.650298
14 2011-02-26 1.677629
15 1988-02-24 1.691611
16 1982-02-17 1.713860
17 2016-02-17 1.729589
18 1983-02-25 1.738279
19 1986-02-27 1.763319
20 1987-02-24 1.781372
21 2009-02-22 1.794061
22 1991-02-25 1.797485
23 2005-02-25 1.798750
24 2007-02-19 1.821313
25 1989-02-21 1.841981
26 2017-01-29 1.876840

Tigertown

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Re: Sea Ice Extent around Antarctica
« Reply #378 on: January 30, 2017, 04:57:36 PM »
Tomorrow.

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Re: Sea Ice Extent around Antarctica
« Reply #379 on: January 31, 2017, 01:19:55 AM »
Those figures from Wipneus are intriguing. If extent falls another 10% it will be a new satellite-era low and most contributors seem to expect that will happen. Yet apply a 10% fall to the current area figure and this year would only be in around 15th spot. Another oddity is the 1993 area which is hugely lower than any other year. Any suggestions as to what is/has been going on?

Tigertown

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Re: Sea Ice Extent around Antarctica
« Reply #380 on: January 31, 2017, 04:35:33 AM »
For Jan. 30th JAXA has posted 2,468,573 km2 for SIE around Antarctica.

Down by 35,574 km2.

Paddy

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Re: Sea Ice Extent around Antarctica
« Reply #381 on: January 31, 2017, 09:03:06 AM »
Current concentration map shows lots of low concentration ice in the Belliingshausen sea, small amounts elsewhere:


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Re: Sea Ice Extent around Antarctica
« Reply #382 on: January 31, 2017, 09:35:08 AM »
Those figures from Wipneus are intriguing.

Yes, area at rank 26 out of 39 does not seem to be particularly low. It indicates relative high compactness (area/extent, no graph yet) of the remaining ice pack. 

I left out the higher values minimums, that may be interesting too, here they are:

26 2017-01-29 1.876840
27 1979-02-20 1.926174
28 2012-02-23 1.931870
29 2010-02-20 1.933016
30 1995-02-17 2.002174
31 1990-02-22 2.026988
32 1994-02-18 2.098845
33 2004-02-22 2.154999
34 2008-02-20 2.203494
35 2001-02-19 2.286595
36 2013-02-20 2.389945
37 2015-02-14 2.414870
38 2014-02-19 2.423633
39 2003-02-27 2.448344


So we area about midway between the highest (2.448, 2003) and the lowest (1.248, 1993).

Tealight

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Re: Sea Ice Extent around Antarctica
« Reply #383 on: January 31, 2017, 10:51:38 AM »
/Those figures from Wipneus are intriguing. If extent falls another 10% it will be a new satellite-era low and most contributors seem to expect that will happen. Yet apply a 10% fall to the current area figure and this year would only be in around 15th spot. Another oddity is the 1993 area which is hugely lower than any other year. Any suggestions as to what is/has been going on?

I think in 1993 strong foehn winds moved over the Antarctic Peninsula and reduced the Weddel Sea to rubble. The whole east coast of the Peninsula was ice free. Maybe this was a preconditioning for the Larsen A breakup.

On my website the AWP daily animations show the whole 1992/93 melting season.
https://sites.google.com/site/cryospherecomputing/warming-potential/Albedo-Warming-Overview/1992-3

« Last Edit: January 31, 2017, 11:47:43 AM by Tealight »

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Re: Sea Ice Extent around Antarctica
« Reply #384 on: January 31, 2017, 02:01:49 PM »
NSIDC extent : 2.496M down  -15.9k. 2017 Ranking for the lowest minimum unchanged at #7
NSIDC area: 1.855M down  -22.2k. 2017 Ranking for the lowest minimum unchanged at #26

Paddy

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Re: Sea Ice Extent around Antarctica
« Reply #385 on: January 31, 2017, 02:37:21 PM »
How do the area figures for this date compare with previous?

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Re: Sea Ice Extent around Antarctica
« Reply #386 on: January 31, 2017, 03:12:35 PM »
How do the area figures for this date compare with previous?

Good question, that is the proper comparison of course. Here are the bottom ten for extent and area:

NSIDC extent SH
2007-01-30 3.317009
1988-01-30 3.293921
2016-01-30 3.281563
1985-01-30 3.236064
1984-01-30 3.171942
1997-01-30 3.073323
1993-01-30 3.055230
2011-01-30 3.051893
2006-01-30 2.965328
2017-01-30 2.496448
NSIDC area SH
2002-01-30 2.215836
2016-01-30 2.163698
1981-01-30 2.157176
2000-01-30 2.140510
1985-01-30 2.130137
1984-01-30 2.098387
1997-01-30 2.059385
2006-01-30 2.017084
2017-01-30 1.854593
1993-01-30 1.725503


So we have a first and a second place for extent and area.

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Re: Sea Ice Extent around Antarctica
« Reply #387 on: January 31, 2017, 03:27:08 PM »
Quote
2011-01-30 3.051893
2006-01-30 2.965328
2017-01-30 2.496448

So we're almost 16% below the previous record low NSIDC extent for this date.  16% is a pretty good chunk.

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Re: Sea Ice Extent around Antarctica
« Reply #388 on: January 31, 2017, 04:04:17 PM »
"Any suggestions?"
Maybe 93 opened up avenues for ocean currents to begin acting on basal ice, the melting and spreading of which added to sea ice cover. Perhaps now most of the 'easy' ice has gone slowing basal melt etc. and leading to a new phase in Antarctic melt. On the other hand it's been a strange year all round and next year may be more typical.

Gray-Wolf

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Re: Sea Ice Extent around Antarctica
« Reply #389 on: January 31, 2017, 06:10:34 PM »
I'm worried that the change in Pacific drivers to positive, back in 2014, combined with a healing Ozone hole has put us back into 'ice loss' around Antarctica. The trouble with Antarctic ice is when storms disturb the outer ice it can float off and so inflate extent giving a false picture? What is viewed as ice growth is, in fact, ice collapse?

If we see poor growth over the Southern winter ( with the Southern continents suffering cold plunges and Antarctica seeing WAA) then we must begin to consider that Antarctica will now begin a downward trend is Sea ice and an uptick in Shelf calving.
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FredBear

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Re: Sea Ice Extent around Antarctica
« Reply #390 on: January 31, 2017, 07:11:46 PM »
If bits of Larsen C (and any other icebergs/shelves) just drift off north, they will not make much difference to SIE. They may, however, block circulation in parts of the sea if they get grounded and that may increase SIE.
It is if they collapse like Larsen B that they can prop up extent for years (decades?) by reinforcing the sea ice building during the following winters? (I feel that the Weddell Sea used to have less SIE before 2002?).

oren

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Re: Sea Ice Extent around Antarctica
« Reply #391 on: January 31, 2017, 09:38:16 PM »
If bits of Larsen C (and any other icebergs/shelves) just drift off north, they will not make much difference to SIE. They may, however, block circulation in parts of the sea if they get grounded and that may increase SIE.
It is if they collapse like Larsen B that they can prop up extent for years (decades?) by reinforcing the sea ice building during the following winters? (I feel that the Weddell Sea used to have less SIE before 2002?).
Looking at a chart of Weddel Sea extent at the current date over the years, there does did seem to be a general upward trend, but I can't see any specific change point following 2002.

DavidR

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Re: Sea Ice Extent around Antarctica
« Reply #392 on: February 01, 2017, 01:23:01 AM »
"Any suggestions?"
Maybe 93 opened up avenues for ocean currents to begin acting on basal ice, the melting and spreading of which added to sea ice cover. Perhaps now most of the 'easy' ice has gone slowing basal melt etc. and leading to a new phase in Antarctic melt. On the other hand it's been a strange year all round and next year may be more typical.
One possibility is that the global cooling that occurred after the Mt Pinatubo eruption reached the Arctic and Antarctic during 1993 causing a significant decline in temperatures and subsequent  increases in Sea Ice. Both the Arctic and the Antactic show a significant decline in temperatures in 1993. Comparison with the effects of an El Nino suggests that the polar temperature shifts have a tendency to trail global temperature shifts by a year or two.

Measured at the 60-80 lattitudes, average annual Antarctic temperatures dropped from -15.3 in 1991 to -16.5 in 1993.  The 1993 minimum would have occurred before the 1993 average dropped. They did not return above -15.3 until 2001. 
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Tigertown

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Re: Sea Ice Extent around Antarctica
« Reply #393 on: February 01, 2017, 05:33:14 AM »
For Jan. 31st JAXA has posted 2,449,346 km2 for SIE around Antarctica.

Down by 19,227 km2.

Weddell Sea concentration loss from storm.CLICK IMAGE
« Last Edit: February 01, 2017, 05:42:06 AM by Tigertown »

Wipneus

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Re: Sea Ice Extent around Antarctica
« Reply #394 on: February 01, 2017, 03:16:29 PM »
SH NSIDC extent drops -8k5, SH NSIDC area drops -14k9.

Small changes, but in the ranking of annual minimums both extent and area did rise one place. Extent now #6, area is #25.

Extent
1 1997-02-27 2.264152
2 1993-02-19 2.280783
3 2011-02-22 2.318847
4 1984-02-27 2.381731
5 2006-02-20 2.486597
6 2017-01-31 2.487992
7 1992-02-23 2.492393

Area
1 1993-02-26 1.248163
2 1984-02-27 1.509585
3 1996-02-25 1.535481
4 2000-02-18 1.561033
5 2006-03-04 1.565059
6 1999-02-26 1.577058
7 1981-03-03 1.588790
8 1997-02-19 1.589288
9 1985-02-19 1.635733
10 1992-02-23 1.641926
11 1980-02-27 1.646186
12 2002-02-20 1.649281
13 1998-02-26 1.650298
14 2011-02-26 1.677629
15 1988-02-24 1.691611
16 1982-02-17 1.713860
17 2016-02-17 1.729589
18 1983-02-25 1.738279
19 1986-02-27 1.763319
20 1987-02-24 1.781372
21 2009-02-22 1.794061
22 1991-02-25 1.797485
23 2005-02-25 1.798750
24 2007-02-19 1.821313
25 2017-01-31 1.839665
26 1989-02-21 1.841981


No changes in the daily positions, extent is lowest and area the second lowest for the date.

johnm33

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Re: Sea Ice Extent around Antarctica
« Reply #395 on: February 01, 2017, 10:06:54 PM »
DavidR Your suggestion makes more sense.
Tigertowns animation is good but more detail shows on the original site, I ran it from the 26th to the 9th at one fps it looks like a big crack shows up on the 3rd then stretches next the northern ice disconnects from the peninsular but again these show best in animation. Is Larsen about to get a push?


Tigertown

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Re: Sea Ice Extent around Antarctica
« Reply #396 on: February 02, 2017, 05:25:35 AM »
For Feb. 1st JAXA has posted 2,422,393 km2 for SIE around Antarctica.

Down by 26,953 km2.

crandles

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Re: Sea Ice Extent around Antarctica
« Reply #397 on: February 02, 2017, 02:23:17 PM »
IJIS 2.42

170k above record low

lost just 80k in last 3 days (much slower than the approx 70k per day before that)

At that rate it would take until Feb 18 to reach 2 million, but further slowing might be expected as the minimum is approached. So perhaps beginning to look like it will stay above 2 million km2. Of course this is dodgy reasoning, a couple of days of large falls or rises could result in a very different conclusion.

Looks smoother than Arctic but could still change direction and this could have large effect yet.

Wipneus

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Re: Sea Ice Extent around Antarctica
« Reply #398 on: February 02, 2017, 02:38:12 PM »
SH NSIDC extent, area lost -13k5, -24k6 today.

In the rankings of the lowest annual minimums, 2017 overtook one year in eacht ranking. Extent is now #5 , area is #24.

Extent
1 1997-02-27 2.264152
2 1993-02-19 2.280783
3 2011-02-22 2.318847
4 1984-02-27 2.381731
5 2017-02-01 2.474530
6 2006-02-20 2.486597
Area
1 1993-02-26 1.248163
2 1984-02-27 1.509585
3 1996-02-25 1.535481
4 2000-02-18 1.561033
5 2006-03-04 1.565059
6 1999-02-26 1.577058
7 1981-03-03 1.588790
8 1997-02-19 1.589288
9 1985-02-19 1.635733
10 1992-02-23 1.641926
11 1980-02-27 1.646186
12 2002-02-20 1.649281
13 1998-02-26 1.650298
14 2011-02-26 1.677629
15 1988-02-24 1.691611
16 1982-02-17 1.713860
17 2016-02-17 1.729589
18 1983-02-25 1.738279
19 1986-02-27 1.763319
20 1987-02-24 1.781372
21 2009-02-22 1.794061
22 1991-02-25 1.797485
23 2005-02-25 1.798750
24 2017-02-01 1.815087
25 2007-02-19 1.821313


The daily rankings did not change. Extent is still the lowest and area the second lowest for the same day.

Tigertown

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Re: Sea Ice Extent around Antarctica
« Reply #399 on: February 03, 2017, 05:32:33 AM »
For Feb. 2nd JAXA has posted 2,390,157 km2 for SIE around Antarctica.

Down by 32,236 km2.