UPDATE: Two commenters pointed me to the Polar Science Center. They look to have the best Arctic ice volume model around — and it’s been validated (see below). Note: “Anomalies for each day are calculated relative to the average over the 1979 -2009 period for that day to remove the annual cycle.”
The big Arctic news remains the staggering decline in multiyear ice — and hence ice volume. If we get near the Arctic’s sea ice area (or extent) seen in recent years this summer, then this may well mean record low ice volume — the fourth straight year of low volume. And the latest extent data from the National Snow and Ice Data Center suggests we will:
Ed. - NOTE: 10 May 2010 GraphOf course, the anti-science crowd — and much of the media — remain stuck in two-dimensional thinking. So the headlines last month were mostly about how the Arctic ice was supposedly “recovering” to the 1979-2000 average. Now, it was reasonable to ignore the third dimension — ice thickness — when we didn’t have good data on it. But now we do, so it is unreasonable to continue focusing on just two dimensions in the Arctic.
Trends in multi-year ice — ice volume — are what matter most in terms of the long-term survivability of the Arctic ice in the summer (see New study supports finding that “the amount of
sea ice in the northern hemisphere was the lowest on record in 2009"). As we’ll see, even when the ice was supposedly recovering in area 2008 and 2009, it was still rapidly shedding the thickest ice — ice older than 2 years. I noted in March that, contrary to much misreporting, no study has yet been published undermining our understanding that human emissions are the primary cause of the long-term decline in Arctic ice volume — a decline that shows no sign of reversal (see Study: “It is clear … that the precipitous decline in September sea ice extent in recent years is mainly due to the cumulative loss of multiyear ice,” Physicist: “If temperatures change just a few tenths of a degree then this oh-so-thin ice cap is doomed.”)
EDIT
http://climateprogress.org/2010/05/13/arctic-ice-volume-nsidc-polar-science-center/