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Friday, January 27, 2012

A link between Arctic sea ice and recent cooling trends over Eurasia by S. D. Outten & I. Esau, Climatic Change 110 (2012); doi: 10.1007/s10584-011-0334-z

Climatic Change, 110(4-3) (2012) 1069-1075; doi: 10.1007/s10584-011-0334-z

A link between Arctic sea ice and recent cooling trends over Eurasia

S. D. Outten and I. Esau (G. C. Rieber Climate Institute, Nansen Environmental and Remote Sensing Center, Thormhlensgt. 47, 5006 Bergen, Norway)


A band of cooling that extends across mid-latitude Eurasia is identified in the wintertime surface air temperatures of the latest ECMWF reanalysis. This cooling is related to extreme warming around the Kara Sea through changes in the meridional temperature gradient. Surface temperatures in the Arctic have risen faster than those at lower latitudes, and as the Arctic warming increases, this north–south temperature gradient is weakened. This change in the meridional temperature gradient causes a decrease in the westerly winds that help maintain the mild European climate by transporting heat from the Atlantic. Since decreasing sea ice concentrations have been shown to be a driving factor in Arctic amplification, a singular value decomposition analysis is used to confirm the co-variability of the Arctic sea ice, including the Kara Sea, and the temperatures over the mid-latitude Eurasia. These findings suggest that decreasing sea ice concentrations can change the meridional temperature gradient and hence the large-scale atmospheric flow of the Northern Hemisphere.

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