RealClimate: We noted earlier that the Artic sea-ice is approaching a record minimum. The record is now broken, almost a month before the annual sea-ice minima usually is observed, and there is probably more melting in store before it reaches the minimum for 2012 - before the autumn sea-ice starts to form. The figure shows annual
You are here: Home / Climate Science / An update on the Arctic sea-iceAn update on the Arctic sea-ice 26 Aug 2012 by rasmus We noted earlier that the Artic sea-ice is approaching a record minimum. The record is now broken, almost a month before the annual sea-ice minima usually is observed, and there is probably more melting in store before it reaches the minimum for 2012 – before the autumn sea-ice starts to form. The figure shows annual variations in the area of sea-ice extent, and the x-axis marks the time of the year, starting on January 1st and ending on December 31st (for the individual years). The grey curves show the Arctic sea-ice extent in all previous years, and the red curve shows the sea-ice area for 2012. (The figure is plotted with an R-script that takes the data directly from NSIDC; the R-environment is available from CRAN) UPDATE on the update The National Snow and Ice Data Center announced today (August 27th, 2012) that the 2007 record has now been broken by their more conservative 5-day running average criterion. They also note that “The six lowest ice extents in the satellite record have occurred in the last six years (2007 to 2012).” Filed Under: Climate Science About rasmusD. Phil in physics from Atmospheric, Oceanic & Planetary Physics, Oxford University, U.K. Funding: governmental (Norwegian Science Foundation) Reader Interactions343 Responses to "An update on the Arctic sea-ice" Comments pagination 1 2 3 … 7 Next » Miguelito says 26 Aug 2012 at 11:09 AM Has anybody looked at the dates of the year for the minimum and maximum ice coverage and considered whether they’ve changed too? Presumably, over the time series, the average date of maximum sea-ice coverage would move earlier and the date for minimum sea-ice coverage would move later. Kees van der Leun says 26 Aug 2012 at 11:10 AM Do these data have the running 5-day averaging that (I think) NSIDC usually applies in its own communication? dbostrom says 26 Aug 2012 at 11:52 AM Mark that the only concrete urgency and most of the news from the Arctic has to do with our pathetic eagerness to go “up” and extract freshly available hydrocarbons so we can literally add gasoline to the fire consuming us. How very wise we are. Who needs an Oracle of Delphi speaking in riddles? Pete Dunkelberg says 26 Aug 2012 at 11:59 AM Capital Climate covers divers records and events including Tropical rainfall rate in arctic Alaska. The questions of comments 1 & 2 are probably answered at the remarkable Ice Empiricist blog. Walt Meier says 26 Aug 2012 at 12:04 PM These are daily values, not the 5-day average, which is not quite at a record yet. Using a 5-day average removes some of the noise due to weather and other effects that cause small errors in the daily values. Thus the 5-day estimate is a more robust measure of sea ice changes. We will make an announcement on our web site when we have passed the current record: http://nsidc.org/arcticseaicenews/ Walt Meier NSIDC [Response:Walt, thanks for stopping by, and for that clarification.–eric] [Response:Thanks indeed Walt. By the way, it is worth noting that while a trailing moving average does average out noise, this can come at a cost when the time series is non-stationary (as this clearly is): the moving average will necessarily dampen the trend near the end point of the series. The stronger the trend, the more this is so, so I think that is a problem here. Application of the same 5 day trailing average to the 2007 series (where the decline was much less steep at this point of the season than it is in the current case) is likely to have led to a less severe dampening of the decline than it is having now, where the decline is still quite steep. I believe that this likely has led to a spurious delay (by a day or two) in declaring the 2007 record beaten. Just my two cents. -mike] Killian says 26 Aug 2012 at 12:14 PM @Miguelito: https://sites.google.com/site/pettitclimategraphs/ wili says 26 Aug 2012 at 12:22 PM Let me play devil’s advocate–though the MSM is playing that role quite well by it’s deafening silence on the issue: Why should we care? It’s just ice. Maybe not a good thing for some polar bears and Inuit, but why should the rest of us take even a moment out of our busy lives to worry about these developments? Kevin McKinney says 26 Aug 2012 at 12:26 PM Neven and I try to summarize some of the consequences, insofar as they are known at this point, in a new post at the Arctic Sea Ice blog: http://neven1.typepad.com/blog/2012/08/wasislac.html#more Kees van der Leun says 26 Aug 2012 at 12:26 PM @Walt (4) Thanks, that’s what I thought. The noise on the red line during the past few weeks doesn’t look too impressive though. Hardly shows at this steep gradient. James Staples says 26 Aug 2012 at 12:49 PM Hmmmm…..say, could I interest anyone in a little ‘soon-to-be-oceanfront properties’ in, say, the foothills of the Brooks Range? richard pauli says 26 Aug 2012 at 12:58 PM Let’s get real. The big questions no...