http://climatechangepsychology.blogspot.com/2009/02/nsidc-arctic-sea-ice-extent-graph.html
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Update of Feb. 18, 2009: Apparently, there was a problem with one of the sensors that feeds the data on sea ice extent to NSIDC beginning in January. By February 18, it was as large as 500,000 sq. km. They have taken the graph offline until they can get things corrected. See their explanation here (click here, and hit page-down two or three times).
Updated graph from Feb. 17, 2009:
Graph from Feb. 15, 2009: The last time I saw the National Snow and Ice Data Center Arctic Sea Ice Extent graph go off looking like a wet noodle, it was due to some data that had not been smoothed for a week or some such thing. These days, the legend says the graph is updated every day, but maybe not... (click on it to enlarge the details).
Link to the NSIDC's news page: http://nsidc.org/arcticseaicenews/
You are right that the graphs often change a bit after smoothing, but these sorts of hooks to pop up from time to time. Ice formation isn't exactly a linear function. We will have a clearer picture in a few days.
ReplyDeleteThat said, the extent now isn't the most important time frame; we have to wait for greatest extent to see if there is a significant issue.
THAT said, the fact the ice is even tracking the previous lowest winter extent probably tells us something about how much heat has been absorbed over the last four seasons. I'm betting the ice is not only low in extent, but is also hitting lows in thickness/mass for winter, also. If so, even a normal summer summer will likely see another significant melt cycle. A warm and/or stormy summer, and/or the wrong kinds of winds could bring us another record low ice extent and mass.
And that's not including the methane in the upper water and in the air just above.
Cheers
Ok, I was following you all the way until you got to the bit about methane. Of course, that is perhaps related to the mental image I have of the methane all being over there on the Siberian side in the tundra and just off shore. I never think about the Canadian archipelago or Alaska.
ReplyDeleteCan you elucidate a bit more, please?
Tenney,
ReplyDeleteYes, there is a lot of methane throughout the Arctic region, not just in Siberia. There have been tons of articles over the years about infrastructure problems in Alaska due to permafrost melting. Anywhere that happens, you've got additional methane/CO2 releases.
The reference to the water came from the Russian/European research this past summer/fall that has been widely reported on. They found very high methane concentrations just below and just above the water line in the Arctic, presumably (certainly, imho) from methane clathrates.
Personally, I think the locations of the higher rates of sea ice melt is probably correlated somewhat with the methane concentrations. Notice how the ice melts away in the areas north of Siberia and Alaska? Now, that might be due to currents and winds, but I suspect methane is playing some role there. You don't see the melt so strongly north of the Canadian Archipelago, which is more rock than soil.
Then there are those thermokarst lakes...
We are in deep, deep doo-doo.
Cheers