New study supports finding that “the amount of [multi-year] sea ice in the northern hemisphere was the lowest on record in 2009″
Map of air temperature anomalies for December 2009, at roughly 3,000 feet above surface, Areas in orange and red are warm anomalies, areas in blue and purple are cool.
It’s cold here and in northern Eurasia, but it’s been positively toasty ar0und the Arctic circle — thanks to an extreme negative phase of the Arctic Oscillation, as the National Snow and Ice Data Center (NSIDC) explained in their online report yesterday.
The temperatures reported by NSIDC show some Arctic anomalies exceeding 7°C (13°F)! That’s not good news for the kind of re-freezing one wants to see in the otherwise rapidly melting Greenland ice sheet (see Nature: “Dynamic thinning of Greenland and Antarctic ice-sheet ocean margins is more sensitive, pervasive, enduring and important than previously realized”). It’s also one reason “December 2009 had the fourth-lowest average ice extent for the month since the beginning of satellite records, falling just above the extent for 2007. The linear rate of decline for December is now 3.3% per decade.”
Significantly, a new study, “Perennial pack ice in the southern Beaufort Sea was not as it appeared in the summer of 2009” by Barber et al. finds that all the crowing by the anti-science crowd about the supposed “recovery” of Arctic sea ice was quite premature: