Further to lodger's comments on salinity gradients... The extra heat in the Arctic overwinter has been noted. This cannot, imho, be explained by the increase in CO2 from 400 to 404ppm. It cannot be explained by sunlight. There is no observed relentless season-long extra inflow of warmer air from lower latitudes. There are some great oddities along the path of the Gulf Stream, at lower latitudes, with maasive positive anomalies off the US Eastern seaboard abruptly transitioning, round the Grand Banks, to negative anomalies all the way to Iceland, and beyond. See here... https://robertscribbler.files.wordpress.com/2016/01/hot-water-hot-water-everywhere.gif?w=600&h=383 This looks to me like a very strong, heated Gulf Stream meeting, and flowing underneath, fresher water, flushed from the Arctic. The Gulf Stream heat then reappears in the Barents Sea. I should also suppose it is likely, having lost less heat to tha atmosphere than in a normal year, to enter the Arctic through the Fram Strait warmer, and thus more buoyant, than usual, thus displacing more of the "Polar Mixed Layer" per lodger's illustration above, and getting sufficiently close to the surface as to cause the observed +25C temperature anomalies. I can't see what else could possibly be the culprit for these massive SAT anomalies, the feeble volume growth overwinter, and now the extremely rapid start to the melt season.

The issue in a nutshell... The extraordinary temps over the winter suggest that an extra source of additional heat has been arriving in the Arctic. There are a lot of discussions of how this has affected ice formation overwinter. Warm atmosphere=less ice. I would suggest that it is highly possible that this extra heat input, which caused a warmer winter atmosphere, will continue to input throughout the summer, as it is very possible that it is not seasonally cyclic.

Yes Chris, I'd agree that we don't know about thesituation at depth. While there is an undersea boundary between the Atlantic and the Arctic, the "aperture" through which water can flow on the Atlantic side is ?a thousand times? larger than on the Pacific. In an ordinary year, Atlantic water heat keeps the AB, Greenland and Barentzs Seas ice free in winter up to around 80N in places. So it is significant. It is partially isolated from the ice at surface by the salinity gradient. But what would happen if the continued arrival of hotter, more buoyant ex-Gulf Stream water arrived at a shallower depth, over decades. I would expect this to gradually erode the freshwater layers within the Arctic, and to flush some more of the resultant brine elsewhere, most probably the North Atlantic, via, for example, the Labrador current. Extra fresher water in the North Atlantic, with perhaps a further contribution from Greenland run-off, could then further exacerbate the situation, by forming a surface layer that would prevent the exchange of heat from the North-flowing Gulf Stream to the atmosphere at lower latitudes. Which might look like this... http://www.esrl.noaa.gov/psd/map/images/sst/sst.anom.seasonal.gif ...which could further result in warmer, more buoyant water, which has retained more of its heat during its journey, entering the Arctic at a shallower depth, further displacing more of the freshwater layer, and (in winter) releasing a lot of heat to the Arctic atmosphere and (in summer) melting ice. The energy which has heated the Arctic atmosphere this past winter, if it continues to arrive throughout the summer, will not be released into the atmosphere; and the temp at 80N+ will be as usual, about 2C. It is, in my view, likely to continue to arrive - this may be a cyclical change, but it's as likely to be a decadal rather than a seasonal cycle - and I would expect that the winter energy transfer from ocean to atmosphere will, in summer, become an energy transfer from ocean to ice.

Chris, Yes, (sorry all for the incoherence - post was eaten by typepad, copied, and pasted, and reposted, in the wrong thread.)

Hi Chris, WRT your para 1; I am not aware of that. Nor are the authors, nor you. Op cit: your last sentence. Certainly, with the vast majority of extra thermal energy caused by FCAGW now stored within the oceans, we can expect that major oceans currents will begin to act in unusual, unexpected ways; almost certainly in ways beyond human comprehension, or computation. Your data on airflow eliminates another possible variable from my "control experiment". So I think there is a very good possibility that extra thermal mega-giga-mega-giga-Joules have been flowing Northwards, at a shallower depth, this winter. I can't see why sunrise would affect this. Weather in May is weather. Has the Arctic been experiencing inreasingly sunnier Mays since 1979? Changes in ocean currents define new climates. In my view, the Arctic is, bathymetrically, a part of the Atlantic that looked a bit odd, when examined from above. Weather in May: trivial interannual variation. CO2: longterm downward trend. Ocean currents: who knows? There may be some signs of mischief already afoot; and the extra OHC from FCAG can multiply its own effect by misdirecting existing forces, which have been accumulated, and stored as both kinetic and thermal energy, over the previous 4 billion

FWIW, this is my take, which hasn't changed much... Over this winter, there has been a clear thermal anomaly in the Arctic atmosphere. Of the two possible contibuting agencies, sunlight cannot be responsible. Classic control test... The extra thermal energy then must originate from seawater currents, which have either been anomalously warm, or closer to the surface than usual. (Extra heat trapped by clouds or CO2 I assume to be trivial, and certainly unlikely to have suddenly brought on such a huge departure from the expected.) There are IIRC 7 Sverdrups of some current, that originates off Florida as the Gulf Stream, flowing northwards through the Fram Strait, at depth. If it's flowing tens of metres higher in the water column, that's the only likely explanation I could posit for the winter's oddities. There does seem to be some evidence of some disruption in the Gulf Stream further South, with the persistent North Atlantic cool spot - perhaps a precursor of Hansen's freshwater lens? - suggesting that less thermal energy is flowing from ocean to atmosphere at lower latitudes. And that thermal energy has to go somewhere, and it's heading North. And it may well be slightly warmer, and thus more buoyant, when it gets there. I can't see any reason why the change in insolation is going to affect this. So I think that a new minimum is very likely, and with weather conditions conducive to melting - if Apollo joins Poseidon - then ice-free (less than 1Mkm2) is possible. But then, having seen the latest data from CT, it turns out that Dr Inferno's forecast is also holding up well, so far.

Best not call the maximum until we find out if the ice area has gone up from March to September... http://denialdepot.blogspot.fr/2016/03/ice-age-confirmed.html

Hi Neven, I think that by far the most significant and notable feature is the record low max in the Arctic Basin, which doesn't show up well in the regional graph... http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/recent365.anom.region.1.html ...because of the scale of the y axis. But the extra open water, within the 80°N circle, at anything from 5°C to 40°C hotter than ice would be in these latitudes has pushed daily SATs up to over 20°C anomalies in the area just North of Svarlsbard across to Northern Novaya Zemlaya, consistently for months on end. The monthly anomaly maps, with a scale that ends at 6°C don't do it justice. A collossal amount of heat is being pumped into the Arctic atmosphere here.

Hi Jim, A little loose on the definition - and just by eyeballing this... http://arctic.atmos.uiuc.edu/cryosphere/arctic.sea.ice.interactive.html ...and comparing the likely suspects with the data. 2012 stopped having a bigger anomaly on day 320 (about 15 November), and the earliest I can find an anomaly greater than the present -1.450 is round about day 165 (about 15 May).

Hi all, (long time, no speqk) The other record going uncommented-upon is that AFAICT, the current Arctic SIA anomaly is the greatest ever, not just for this date, but for any midwinter date.

http://nsidc.org/arcticseaicenews/2014/09/arctic-minimum-reached/ also http://www.theguardian.com/environment/blog/live/2014/sep/23/un-climate-change-summit-in-new-york-live-coverage

Hi Eric, Neven wrote about his own feelings on this in a post featured in the "Best of Blog" box, above and to the right, called "To Melt or Not To Melt." I think that the fast melt off Alaska is a delayed symptom of the heatwave in Alaska in January and February, when temps were actually above freezing for some time. Looking through the previous years plots, it seems to me that in Chukchi, ESS and Laptev, the closest parrallel to this year is neitherr 2012, nor 2013, but 2007. 2014 differs from 2007, in that the Atlantic side looks much weaker than then, similar to all recent years. FWIW, I think that we are going to see a spectacular melt all along Eurasia, with the Northern Sea Route open for a record long period; and the possibility of clear blue water at the Pole. OTOH, it has been abnormally cold for recent years everywhere in the quarter from the Pole to due South and due West. I think that the Hudson Bay will clear late; the melt in the Baffin Bay will be slack; and the NW Passage through the Canadian Archipelago may not clear at all. And if none of the above happens, I shan't be terribly amazed, and I'll blame the weather. Sea ice is, I find, a very disobedient substance, which very rarely sees fit to do as it's told.

Hi Neven, Climate Central/SciAm has an article on precisely this subject: http://www.climatecentral.org/news/melt-ponds-arctic-sea-ice-17429 Robert scribbler is predicting a heatwave... http://robertscribbler.wordpress.com/2014/05/18/arctic-heatwaves-rise-to-threaten-sea-ice-as-lake-baikal-wildfires-reignite/ The new ice surface temp map from DMI seems to me to be very relevant to meltponds... http://ocean.dmi.dk/arctic/ice_temp/index.uk.php ...but this seems to be having technical diffiulties.

Eh? Reportingclimatescience reports on a paper that shows that RISING tropical Pacific SSTs are exacerbating Greenland melt; and finds an expert from AWI who explains that it's due to FALLING tropical Pacific SSTs. Is the tropical Pacific warming or cooling? (In anticipation of the Californian drought having an adverse effect on the global price of wine, I have taken early precautionary action, and am quite unable to answer this question for myself. Any elucidation would be gratefully received;), tomorrow.

Trick question! As the North Pole is in all 24 timezones simultaneously, it is impossible to say it was put down at 1800. In the adjacent timezone, it would be simultaneously 1900, and so on round the compass. It is worth noting that nobody claims to have set foot on the North Pole until 1907... http://en.wikipedia.org/wiki/North_Pole I know of three bloggers who occasionally write about the history of the Arctic; 1. Patrick LOckerby is excellent... http://www.science20.com/the_chatter_box 2. 'climatereason' or 'tony b' has read an awful lot of archived material, which he then desperately scours for the extremely scant and unconvincing evidence that the recent melt has happened before. You'd have to search WUWT. 3. The third is insane. Neven, your 'certificate' whatever that is, from Typepad, ran from 1/4/2012 to 5/4/2014.

The new resource... http://nsidc.org/soac apparently has maps for SAT, sea ice, permafrost extent, vegetation, snowcover, and more. Thanks to the scientific community for this speedy response to the request for more data. That's probably enough for one day;)

NSIDC source for the above has a lot more, including an update on multiyear ice, mention of SEARCH and news of a new resource... http://nsidc.org/arcticseaicenews/2014/04/arctic-sea-ice-at-fifth-lowest-annual-maximum/

NSIDC has called the(5th lowest ever) max... http://www.theguardian.com/environment/2014/apr/02/arctic-sea-ice-fall-lowest-levels

They may of course be looking in the wrong ocean. The following graduate paper from 2010 found, astoundingly, that from 1979-2010 the best predictor of ice extent in Beaufort in October is the SST in the Carribean in May... http://edocs.nps.edu/npspubs/scholarly/theses/2010/Jun/10Jun_Stone.pdf ...and ruled out an awful lot of the usual suspects, from ENSO to SIE in the same area earlier the same year. And now, in a most exciting development, the sainted David Sanger has only gone and asked her about this... https://twitter.com/happymegwv/status/451082979897397249 More to follow, I hope, from people like Stone or Dr Tom Murphree, who appear to know what they're talking about, which excludes me, obvs. Ideally, I'd love to see them do a SEARCH prediction based on the Carribean data in May 2014.

Well done Neven, and thanks to Larry for suggesting that other participants might like to write guestposts here. Warmly seconded. If you are party to a group e-mail of participants, Neven, you might like to write to confirm this invitation?

ASIB guest blogger Larry Hamilton speaking live now. What time are you on, Neven? If poss, can you leave a message here just before you start?

Ha Ha, very funny. http://www.theguardian.com/media/2014/apr/01/april-fools-jokes-2014-best-web ;)

IPCC 2 trailer... http://www.theguardian.com/environment/2014/mar/28/ipcc-report-climate-change-report-human-natural-systems

I think that there is another factor to consider, besides the temp increase: lack of pressure increase due to the lag in sea level rise. Past temp increases were slower, so they will have been accompanied by a corresponding sea level rise. If temperature rises say, 2C over 1,000 years, this might cause, say, a sea level rise of 10metres over those 1,000 years. Under current AGW, temps are skyrocketing, but sea level rise will take much longer. So under palaeo conditions, you get a 2C increase, but at 40m depth in ESAS, its now 50m deep. Pressure increases from 5 bar to 6 bar. This 20% increase in pressure would have helped with clathrate stability. In the current rapid change scenario, it won't help. There is no way that sealevel is going to rise sufficiently to mitigate rising temperatures.

I saw tripling/quadrupling over the last decade, judging by your link above.