Antarctic Sea Ice Extent and Area

[Lord M Vader]

As the melting season for the antarctic sea ice seems to have started I think we need a thread which is thought to be used anytime at year to discuss the SIE around Antarctica.

It's fitting that the first post wrt Antarctica SIE is that this years maximum SIE was exceptionally early. According to NSIDC the maximum occurred already by August 31 which is the first time it happens since satellites became operational in 1979 for surveillance of the sea ice there.

To find a lower SIE value for the date of October 10 we need to go back to 1986 and 1984 which were the only other years with a lower SIE for the date. October 10 in 1987 were more or less equal with yesterdays value, though slightly higher.

[Gray-Wolf]

Hi LMV!

I'm expecting quite an active southern Summer Around Antarctica?

I think we are crashing into a 'post ozone hole/IPO positive' future for ice extent seeing a return of the Weddell polynia and lower sea ice extent maximums.

Even though it is a dire thing I will gain some enjoyment in watching the deniers cope with the loss of their 'go to Squirrel'!

[Lord M Vader]

After the record early maximum at August 31 the SIE dropped in the beginning of September and more or less plateued. Since October 6 the SIE numbers have steadily dropped with about 600K and per October 19 we are now at 2nd lowest for the date, trailing behind 1986.

In 1984, the SIE as of October 19 was slightly higher but it was followed by a stall lasting into the beginning of November.

As Gray-Wolf pointing out, I don't rule out the possibility of lower SIE maximums in the next couple of years.

[Tigertown]

Just looking at the graph, it looks like a goodly possibility of a new record minimum. I know it's early, but from what I have read there is an increase of warm water flowing into the area via currents.

[Lord M Vader]

Per NSIDC extent we are down to 16,108 Mn km² which is lowest on record for the date. 1986 is on second place about 120K behind.

[Lord M Vader]

The downward trend continues, 2016 is now 220K ahead of the same time as in 1986.

[Tigertown]

A lot of big drops lately according to JAXA. Another 150k+ reduction today for the Antarctic SIE.

[Tigertown]

Another drop of about 179k km² posted by JAXA.
Seems momentum is building. A lot of large drops over the last week.

[JimboOmega]

Does anyone have graphs like posted above, but that show the previous records too?

[crandles]

Does anyone have graphs like posted above, but that show the previous records too?

Do you mean like attached?
Shows range of 1986 15.94 to 2013 17.63

current value 15.44

To get that just use the bottom grey button shown after the antarctic button at
https://ads.nipr.ac.jp/vishop/#/extent

[Jim Hunt]

Alternatively for NSIDC 5 day averaged extent see:

http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

and click the "Antarctic" tab. Then click "Show all" at bottom right. Here's one I prepared earlier:

http://GreatWhiteCon.info/2016/10/nsidc-and-cryosat-2-agreed-upon-declining-arctic-sea-ice/#comment-216239

[JimboOmega]

Alternatively for NSIDC 5 day averaged extent see:

http://nsidc.org/arcticseaicenews/charctic-interactive-sea-ice-graph/

and click the "Antarctic" tab. Then click "Show all" at bottom right. Here's one I prepared earlier:

http://GreatWhiteCon.info/2016/10/nsidc-and-cryosat-2-agreed-upon-declining-arctic-sea-ice/#comment-216239

Perfect, thanks.

It's a little annoying how they only show previous maximum on their graphs, when minimum seems more relevant.

[Tigertown]

190k+ drop posted by JAXA for Nov 10th. Staying below the curve, even widening ever so slightly.
currently at  15,249,442 km²

[magnamentis]

190k+ drop posted by JAXA for Nov 10th. Staying below the curve, even widening ever so slightly.
currently at  15,249,442 km²

almost in free fall and even though the gap is widening ever so slightly, at that level that "slightly" is huge when it comes to excess energy (heat) in the system.

as an example i would use two "identical" cars running above 300km/h while one of the two is "slightly faster by a 5km/h margin, those 5km/h need 10-20% more horsepower, fuel = energy.

[CalamityCountdown]

Originally posted to "stupid questions", but am following Orens suggestion that it be posted to this board. And after reading so many posts in the recent past by "deniers" claiming that growth in antarctic sea ice compensated for the loss of arctic sea ice, the lack of attention in the media to the satellite era record lows being set every day this week is astounding. Today's NSIDC SIE of 15.3 million km's is 600,000 km's lower than the Nov 11 SIE 15.9 million km's in 1986.

According to nsidc.org "Ice extent is particularly low on both sides of the Antarctic Peninsula. The rapid early reduction in sea ice cover in this region may create favorable conditions for the break up of the eastern Peninsula ice shelves at the end of austral summer. Similar sea ice trends and weather conditions were present during the spring seasons preceding past ice shelf retreats (e.g., 2001 to 2002)".  Raises the question of what is the worst case scenario for this year's Antarctic melt season?

A very good question. I suggest you post this in the appropriate thread, Sea Ice Extent around Antarctica.

[Lord M Vader]

According to NSIDC, there have been a big drop in the SIE the last few days:

November 10: 15,072 Mn km²
November 11: 14,902 Mn km² (-170K)
November 12: 14,615 Mn km² (-287K)
November 13: 14,427 Mn km² (-188K)

The five-day average is 14,86 Mn km². We continue to be lowest on record. On second place is 1986 with a whole 15,715 Mn km² for November 13. It's a staggering -855K lower than 1986 and more than 1,1 Mn km² lower than a bunch of years at third place.

It's going fast now!!

[Tigertown]

That is really something else. I usually check every night with JAXA, which has been down, so I had no idea. There have been some really low SIE minimums, so it would have get pretty low to set a record. At this rate though, who knows?

[Tealight]

What I find most interesting is the anomaly map. It shows that ice isn't just lower near the ice edge, but also close the coast (ice shelfs) and in-between. The Ross Sea Polyna is starting to open a few days earlier than usual too.

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

[abbottisgone]

Antarctic sea ice has gone missing in action ...

[Tigertown]

JAXA  is back up. Their SIE for around Antarctica for Nov. 14th is 14,254,593 km².

JAXA reports 14,097,448 km² for Nov. 15th         -157,145 km²

That's approaching 2.5 million km² less than Nov. 1st

[Tigertown]

For November 16th, JAXA has posted 13,911,676 km².

Down by 185,772 km².    No small drops lately.

[Darvince]

It has been falling by more than twice the pace of all other years and has been the entire reason that global sea ice coverage is now 10 sigma below normal.

[Lord M Vader]

For the last two days, November 15 and 16, the SIE around Antarctica (NSIDC numbers) has dropped -161K and 173K and the daily value for November 16 was 13,954 Mn km².

The main question should be how big impact this will have for absorbing the suns energy? Well, one year is no problem but if this is a new trend it will be troublesome. Much of the sea ice will soon experience sun 24/7.

/LMV

[Gray-Wolf]

Hi L.M.V. !

I've spent the " oh look at Antarctica" squirrel years warning the Deniers that the forcings playing a major role ( according to the science?) in the 2% per decade increases would reverse and the ice fall back to the 70's levels...... and then set about the reductions the models predict.

I'm now wondering if this is what we are now starting to see since the IPO flip in 2014 and Ozone hole repairing itself some more?

Obviously there will be swings in extents year to year but the drop back to 70's values would , I imagine, be pretty quick?

[Ajpope85]

Here's October's anomaly.

[oren]

Hi L.M.V. !

I've spent the " oh look at Antarctica" squirrel years warning the Deniers that the forcings playing a major role ( according to the science?) in the 2% per decade increases would reverse and the ice fall back to the 70's levels...... and then set about the reductions the models predict.

I'm now wondering if this is what we are now starting to see since the IPO flip in 2014 and Ozone hole repairing itself some more?

Obviously there will be swings in extents year to year but the drop back to 70's values would , I imagine, be pretty quick?

As far as my limited understanding goes, Hansen's SLR paper predicted an increase in Antarctic sea ice because of strong freshwater discharge from melting Antarctic glaciers. If that is the case, you should not expect a trend of dropping sea ice extent in the SH.

[Tigertown]

From what I have read about how rough the oceans are right now around Antarctica, I don't think fresh water would stay puddled long. There is a lot of upwelling from the depths. For years this water was cold, but it gradually became warmer and now does more harm than good to both sea ice and ice shelves and some of the glaciers that have a retro-grade from the grounding line inland.

 I think Hansen believed the fresh melt water would have the effect of cooling the surface of the ocean waters. I don't know if he underestimated the amount of warm water upwelling or what, but it's not working out that way. Will have to stay tuned to learn more.

[Lord M Vader]

Hi guys!

A scientific article published online in Nature by Independence Day 2016 discuss the role of IPO on the SIE change in Antarctica during 2000-2014 when IPO mostly was in its negative phase. Since early 2014 the PDO has been positive and it remains to see whether this a sustained change or a temporary flip.

http://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo2751.html

The article is behind a paywall but some insight can be retrieved from:

https://www2.ucar.edu/atmosnews/news/121622/expanding-antarctic-sea-ice-linked-natural-variability

Washingto Post had an extensive covering about the Nature article: https://www.washingtonpost.com/news/energy-environment/wp/2016/07/05/this-new-antarctica-study-is-bad-news-for-climate-change-doubters/?utm_term=.fd3eadeb5ec0

Another interesting article from Nature is discussing for how much longer Antarctica's ocean can resist global warming:

http://www.nature.com/news/how-much-longer-can-antarctica-s-hostile-ocean-delay-global-warming-1.20978

[JimboOmega]

So what exactly is going on this year? Is it just the weather? Is it it something that's preventing glaciers from dumping as much freshwater as usual?

Is this early and strong enough to incur the wrath of positive feedback and warmer than usual waters which will gum up next year's freezing season... or does the presence of glaciers mean that there will be a nice layer of cold, fresh, meltwater atop the southern ocean regardless?

[Tigertown]

Nov. 17th JAXA posted 13,728,295 km² for Antarctic SIE.

Down 183,381 km².

If you ever took any of those college courses that had a separate lab class, you probably remember: what you worked out on paper in the class room was not always exactly what happened in the lab. That was the point of taking the lab, to show how much the real world throws you curves.

I don't know about 2014 and prior, but just comparing this year with 2015, I can see why SIE is dropping fast, and with a lot of time left for melting. The ice is literally shredded.
Note: I kept the same amount of zoom and same location and position for each set of comparisons.

[Tigertown]

And yes I did.I looked all around.

[Tigertown]

And around, for good measure and to avoid any bias.

[Tigertown]

The shape this ice is in with three months to go, and the waters are more open than the Arctic and the seas are rough, can we really not expect the melt rate to increase. How strong is the sun in this area, in regard to insolation? So much open water, already. I assume NSIDC and JAXA use the 15% concentration rule for SIE around Antarctica, no?

Sorry, did not mean to hog the thread. I am just awed by what I see happening. I'll tag up now, and let somebody else post.

[oren]

So what exactly is going on this year? Is it just the weather? Is it it something that's preventing glaciers from dumping as much freshwater as usual?

Is this early and strong enough to incur the wrath of positive feedback and warmer than usual waters which will gum up next year's freezing season... or does the presence of glaciers mean that there will be a nice layer of cold, fresh, meltwater atop the southern ocean regardless?

I remember ASLR posting about a tele-connection from the Pacific to the Southern ocean that brings warm water during El-Nino. I don't have any more info on this.

TigerTown, awesome stuff.

[budmantis]

TigerTown, awesome stuff.

Absolutely. TT, do you have any more of those tinfoil hats?

[LRC1962]

An interesting article of a different type of melting.
http://news.nationalgeographic.com/2016/11/foehn-winds-melt-ice-shelves-antarctic-peninsula-larsen-c/
A thought that crosses my mind that is not talked about is, if you get a flash thaw of 2-3 days that is enough to work water into cracks, but then you go back into deep freeze, would not that open those cracks even farther as the water expands do to water freezing? Then when in the summer as the air warms would not that be weak points for farther melting?

[Gray-Wolf]

That is exactly the freeze/thaw action that split apart Larsen B into long rafts of ice when it collapsed.

When the ice travels over geographic features it tears apart into crevasses which then heal beyond the obstruction but remain as a weak point. The weak points are then exploited by melt water and are reactivated ( as we saw on Larson B) as the snout reaches the warmer conditions at the coast as it pushed out to form the shelf.

Should the bottom be attacked, and the shelf end up floating, I imagine more pressures are brought to bear on those weak point via wind/wave/tidal forcings?

[Tigertown]

JAXA shows a drop of 109,953 km^{2 .}for the 18th of Nov.

The temperature anomaly over Antarctica seems to be waning, for what it's worth. May only be that it's getting further in the season and not necessarily cooling, but the temps. are no longer that higher than what's expected.

[Buddy]

If you put warm water into one corner of a large swimming pool....eventually it's going to make to ALL PARTS of the swimming pool.  And that is what is happening to the Antarctic.

I think the problem with detailed scientific models.....is that they have been TRYING to predict something that has an UNPREDICTABLE TIME SCALE.  All the serious scientists know what is happening and what the root cause is.....but trying to "time it" seems impossible.

It's not surprising to me that the Antarctic sea ice is now decreasing in size to record lows.  IT HAD TO EVENTUALLY.  All parts "of the pool" are now being noticeably affected.  The EXTENT of what is coming may be a surprise (I certainly didn't think that up to 9 feet by 2050 - 2060 was coming)....BUT....the basic physics told me that "some increasingly crappy things" are going to be happening to (1) the ice (2) the level of ocean rise and (3) atmospheric temps.

And I also think that the issue in the publics mind has been "overcomplicated".....and thus dismissed by many of them. 



 

[Tigertown]

For Nov. 19th JAXA  reports Antarctic SIE to be at 13,443,895 km².

That is down 174,447 km² from the 18th.

[AbruptSLR]

I originally post the following in the Arctic folder, but it belongs here as much as there:

While I have no proof of any correlation between the two polar sea ice deviations from their respective norms; nevertheless, I cannot help but to suspect that the recent large El Nino is contributing to the Antarctic low sea ice extent, while the associate weak La Nina is contributing the Arctic low sea ice extent (& and both deviations could be strengthened by positive cloud feedbacks).  Paleo-data and model forecasts provide weight to such a possible chaotic strange (Lorenz) attractor type of behavior.


Edit 1: See the linked article entitled: "Lorenz attractors, fluids, chaos and climate".

https://moyhu.blogspot.com/2016/11/lorenz-attractors-fluids-chaos-and.html

Edit 2: The following four linked references all indicate that consideration of chaos theory's strange attractors in paleo-eras demonstrate that climate sensitivity is higher than traditional (AR5) climate modeling projections have assumed.

1) Jones, R. N. and Ricketts, J. H.: Reconciling the signal and noise of atmospheric warming on decadal timescales, Earth Syst. Dynam. Discuss., doi:10.5194/esd-2016-35, in review, 2016.

http://www.earth-syst-dynam-discuss.net/esd-2016-35/
&
http://www.earth-syst-dynam-discuss.net/esd-2016-35/esd-2016-35.pdf

2) Roger Neville Jones & James Henry Ricketts (2016), "Atmospheric warming 1997–2014: hiatus, pause or regime?"

https://www.researchgate.net/publication/305989994_Atmospheric_warming_1997-2014_hiatus_pause_or_regime

3) Ragone, F., Lucarini, V. & Lunkeit, F. (2016), "A new framework for climate sensitivity and prediction: a modelling perspective", Clim Dyn, 46: 1459. doi:10.1007/s00382-015-2657-3

http://link.springer.com/article/10.1007/s00382-015-2657-3

4) Anna S. von der Heydt, Peter Ashwin (Submitted on 12 Apr 2016), "State-dependence of climate sensitivity: attractor constraints and palaeoclimate regimes",  arXiv:1604.03311


http://arxiv.org/abs/1604.03311
&
http://arxiv.org/pdf/1604.03311v1.pdf

Edit 3: The last linked reference cite model findings indicating that changes in extratropical clouds associated with a reduction in high latitude albedo can impact poleward atmospheric heat transport via changes in the Hadley cell:

Nicole Feldl, Simona Bordoni & Timothy M. Merlis (September 28 2016), "Coupled high-latitude climate feedbacks and their impact on atmospheric heat transport", Journal of Climate, DOI:http://dx.doi.org/10.1175/JCLI-D-16-0324.1


http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-16-0324.1

Abstract: "The response of atmospheric heat transport to anthropogenic warming is determined by the anomalous meridional energy gradient. Feedback analysis offers a characterization of that gradient and hence reveals how uncertainty in physical processes may translate into uncertainty in the circulation response. However, individual feedbacks do not act in isolation. Anomalies associated with one feedback may be compensated by another, as is the case for the positive water vapor and negative lapse rate feedbacks in the tropics. Here we perform a set of idealized experiments in an aquaplanet model to evaluate the coupling between the surface albedo feedback and other feedbacks, including the impact on atmospheric heat transport. In the tropics, the dynamical response manifests as changes in the intensity and structure of the overturning Hadley circulation. Only half of the range of Hadley cell weakening exhibited in these experiments is found to be attributable to imposed, systematic variations in the surface albedo feedback. Changes in extratropical clouds that accompany the albedo changes explain the remaining spread. The feedback-driven circulation changes are compensated by eddy energy flux changes, which reduce the overall spread among experiments. These findings have implications for the efficiency with which the climate system, including tropical circulation and the hydrological cycle, adjusts to high latitude feedbacks, over climate states that range from perennial or seasonal ice to ice-free conditions in the Arctic."

[Tigertown]

From Sept. 1st to Nov. 19th, every fifth day

[Tigertown]

JAXA reports 13,239,201 km² SIE  around Antarctica for Nov. 20th.

Down 204,694 km²

Sept. 1st compared to Nov. 20th

[Darvince]

Tigertown, I really appreciate your efforts in documenting the ongoing rapid decline in the Antarctic sea ice! I'm interested in it almost as much as I am the Arctic sea ice, especially now since it seems to be showing new behavior.

[budmantis]

I'll second that, nice graphic!

[Archimid]

It looks like a potential poof.

[Lord M Vader]

For November 20, the Antarctica SIE saw a double century break. In exact numbers, the drop was -225K. We are now down at 13,258 Mn km² according to NSIDC values.

//LMV

[Buddy]

From Sept. 1st to Nov. 19th, every fifth day

Nice...  And Archimid is spot on....poof is right.

[Tigertown]

For Nov. 21st JAXA reports 13,083,541 km² SIE for the Antarctica area.

That's a drop of 155,660 km².

The graph shows this rate that is averaging out of late to be about the normal rate of melt for Antarctic sea ice over the past years. However, the bigger drops and the mixed in double century plus drops this year have the melt about two weeks or so ahead of schedule and that could easily be enough to wrap up in mid-Feb. under 1M km².

[Buddy]

I am looking for....but cannot find (I've looked on the JAXA site and NSIDC...but maybe I am blind)...the data that sits behind all the graphs they produce.  Specifically:

1)  Antarctic sea ice extent MAXIMUM by year
2)  Antarctic sea ice extent MINIMUM by year
3)  Antarctic sea ice VOLUME MAX by year
4)  Antarctic sea ice VOLUME MIN by year

If I can get the data TABLES then obviously I can cull through and pick out the max and min's myself.  But I can't find access to the tables.  I want to make a couple of bar charts...and need that data to do so.

Anyone have any links that might help me would be greatly appreciated....