It seems to me very expected that volume should increase significantly after the very cold snap. As Dave C has imnvho correctly noted on another thread, this suggests that 2013 may be a recovery year. I wonder if very cold ice is more brittle? Anyone? This might help to explain the cracks... If the ice is colder, with surface air temps of -40C, then the top surface of the ice should be down towards -40C; if the SAT is -20C, the ice surface should be closer to -20C. Given that the ice is still thin, then if colder ice is more brittle, or less able to flex, this would make it more prone to cracking. Yes? No? Maybe? Wrong thread?

Hi Wipneus, On the final graph, you have an uncertainty band indicated for the low point. Perhaps it might be an improvement to include an uncertainty band also for the last actual (modelled) reading - currently at 28 Feb.

Cryosphere Today's annual average area graph peaks today on day yyyy.1863 (approx March 9). All downhill from here.

Hi all, I am off-line most of the time and havent had the time to go thru all comments, so apologies if these are repeats: 1. the ice bridge at Kane is a very odd shape, a pointed gothic as opposed to norman arch; 2. research on the central arctic shipping route here: http://www.guardian.co.uk/environment/2013/mar/04/ships-sail-north-pole-2050 ...looks ludicrously conservative to me.

I met a guy in a pub last year who reckoned he had a wheeled sled pulled by three huskies. The greatest advantage being that, as the huskies were self steering, he could go to the pub, get catastrophically drunk, and even fall asleep on the sled on the way home. He was looking forward to being stopped by the law, and pleading that he was not actually in charge of the vehicle, and that the lead dog was clearly sober. At least, I think that's what he said. I may not be a reliable witness.

hi all, Another notorious hotbed of climate change denialism has apparently taken advantage of the sea ice blogees' distraction and excitement over a new forum to slip out this piece of fossil-fuel propaganda... http://www.skepticalscience.com/2013-arctic-sea-ice-prediction.html ...suggesting the Arctic ice will not disappear until 2034, or summat.

And both the DMI temperature map and the temperature plot are showing extreme cold (links over page on "Daily Graphs". The first time I remember seeing the purple colour appearing on the Surface Air Temp map, and the last temperature plot makes this the coldest day in the Arctic in over four years, since 2009. Caveat; at this time last year, on the Atlantic side, the weakness in the ice was in the thinly iced area of Kara/Barentzs and was expressed as no ice in large parts of those areas. This year, as many people here have noted, the Atlantic seems thinly iced in the area of the Fram Strait, where the ice is much thicker. While this may have caused cracks, it does not register as "ice free" area. Thinner ice cover in Barentzs = no ice. Thinner ice cover in Fram Strait = thinner ice.

The global anomaly is back above zero: http://arctic.atmos.uiuc.edu/cryosphere/timeseries.global.anom.1979-2008

Occasional contributor to this blog, Dr Andreas Muenchow, is in the news here: http://desmog.ca/2013/02/14/us-scientist-caught-canadian-muzzle Further info from his own blog here: http://icyseas.org/2013/02/07/academic-freedom-and-international-collaborations/

The University of Washington response to this has been reposted on, wait for it, you won't believe it, but... WUWT. http://wattsupwiththat.com/2013/02/13/ice-loss-model-verification-via-satellite-observations/ It seems that so many of the faithful called foul on the previous WUWT Sea Ice post that Tony has decided he better post something that even makes any sense. See comments here... http://wattsupwiththat.com/2013/02/12/sea-ice-news-volume-4-1-arctic-ice-gain-sets-a-new-record/ "February 13, 2013 at 3:04 pm Folks that are wailing and gnashing teeth here might like this story I just posted: http://wp.me/p7y4l-kHA" He then, after the UW press release, helpfully provides a link which shows that, at the peak of the melt in 1922, it was considered uncannily weird that a vessel could navigate to 81.29N in ice free waters. They should have waited until February 2013, with ice-free navigation way North of that... http://www.iup.uni-bremen.de:8084/ssmis/arctic_SSMIS_nic.png On a similar note, the ice volume in Jan 2013 appears to be below the minimum volume in September 1979... http://haveland.com/share/arctic-death-spiral-1979-201301.png

There is a good write up of the Cryosat/PIOMAS observations/model issue here: http://www.bbc.co.uk/news/science-environment-21437680 I personally would be very interested to see how the Cryosat figures look if added to any of the excellent graphs from Wipneus, Jim Pettit... It seems to me that the Cryosat data is telling a different story to PIOMAS. From the abstract of the (paywalled) Laxon paper linked in the BBC story... "Between the ICESat and CryoSat-2 periods the autumn volume declined by 4291 km3 and the winter volume by 1479 km3. This exceeds the decline in ice volume in the central Arctic from the PIOMAS model of 2644 km3 in the autumn, but is less than the 2091 km3 in winter, between the two time periods." That's just a completely different shape of graph, no?

From the "some of the people all of the time" department: http://wattsupwiththat.com/2013/02/12/sea-ice-news-volume-4-1-arctic-ice-gain-sets-a-new-record/

er, yes

Er, it's above zero again. In addition to the sea ice, the Northern and Southern polar vortices appear to be doing the opposite of each other. The weakening of the Arctic polar vortex has been well discussed here. New research now suggests that the thinning of the Antarctic ozone layer is strengthening the Southern polar vortex. (Sorry, I've not go the link to hand.)

CT Global Sea Ice Anomaly = - 0.107. Models predict (<95% confidence) regular WUWT sea ice updates imminent.

Hi opensheart, AFAIK there is very little information on sea ice thickness before the satellite era. This, from the Wikipedia on the USS Nautilus's voyage in 1958, may be useful: "The most difficult part of the journey was in the Bering Strait. The ice extended as much as 60 feet (18 m) below sea level. During the initial attempt to go through the Bering Strait, there was insufficient room between the ice and the sea bottom. During the second, successful attempt to pass through the Bering passage, the submarine passed through a known channel close to Alaska (this was not the first choice as the submarine wanted to avoid detection)." In recent years, the Bering Strait is completely ice-free for about 5 months of the year, and, barring icebergs, there is no 60foot thick ice anywhere in the Arctic.

Worth noting that Shell is not the only player. The ExxonMobil/Rosneft partnership has been much less reported, but gets a mention here: http://www.bbc.co.uk/news/world-europe-21119774

More from Jason Box on Dark Snow and Greenland's contribution to sea level here: http://thinkprogress.org/climate/2013/01/29/1511871/alley-warming-will-shrink-greenland-coastal-planners/ Yes, Neven, you slacker, I quite agree with Mrs Neven. It is high time that you asked for contributions on your own behalf ;)

Re the temperature of melt, and whether sea ice can melt from within, see also... http://www.sciencedaily.com/releases/2011/03/110303111810.htm There are certain algae which have evolved to live within the ice, and can engineer it, by producing a natural anti-freeze that brings the melting point down to -10C.

The academic journal "The Cryosphere" has started to pre-publish some papers while they are still in peer-review, seeking crowd-sourced input. So, relevent to Rob's dicussion, of Atlantic heat content, see the paper from 16 January, here... http://www.the-cryosphere-discuss.net/papers_in_open_discussion.html I think that this is an excellent idea. Several contributors here may be able to usefully contribute to the review process; and it speeds up the dissemination of the latest research.

Skpetical science has an interesting piece on Arctic methane: http://www.skepticalscience.com/crycapfour.html

From Climate Central, Andrew Freedman has lots from Dr Cohen on the ongoing sudden stratospheric warming event, (albeit mainly focussed on its impact on the lower 48), here... http://www.climatecentral.org/news/stratospheric-phenomenon-is-bringing-frigid-cold-to-us-15479

Bravo Wipneus! I think it might make your map clearer, and sort out the problem with the palette of colours, if you changed the scale to 2012/13/14/15/16/17/2018-24, or some other cut-off point. Also interested in when the ice extent falls below the oft-used technical definition of "ice-free" @1M km squared. Which year is this, and what does the map look like in that year?

Some UK government hypocricy: http://www.guardian.co.uk/environment/2013/jan/15/uk-arctic-oil-drilling-proposals

A series of 3 documentaries from the BBC, following a polar bear family on Svarlsbard as they nearly die of hunger due to the lack of sea ice over the course of 2012: http://www.bbc.co.uk/programmes/b01pyql5/episodes/guide