HR: 10:20h
AN: C52A-01 INVITED     [Abstracts]
TI: Sea ice retreat and its consequences in greenhouse simulations of climate change
AU: * Walsh, J E
EM: walsh@atmos.uiuc.edu
AF: International Arctic Research Center University of Alaska, 930 Koyukuk Drive, Fairbanks, AK 99775 United States
AB: The retreat of sea ice is a key factor in the polar amplification of greenhouse warming. In this presentation, we compare the greenhouse warmings in the context of sea ice retreat in five global climate models used in the Arctic Climate Impact Assessment. Of these five models, one is relatively sensitive and one relatively insensitive to increases of greenhouse gas concentrations. In addition to the correlation between the magnitude of the Arctic warming and the area of sea ice retreat, there are correspondences between sea ice retreat and the seasonality and spatial pattern of the warming. The warming, which is largest over and near areas of sea ice retreat, is strongest in autumn, immediately following the summer months when the loss of sea ice is greatest (in four of the five models). The ice-related warming, in turn, drives the response of sea level pressure in high latitudes, where the largest decrease of pressure occurs during autumn and early winter. Corresponding changes of precipitation are less systematic, although there are indications of an increase of precipitation in summer and autumn over areas where the sea ice cover has been lost.
DE: 1863 Snow and ice (1827)
DE: 1610 Atmosphere (0315, 0325)
DE: 1620 Climate dynamics (3309)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting