HR: 1340h
AN: H43B-0500    [Abstracts]
TI: Decadal to Century Scale Trends in North American Snow Extent Based on IPCC AR4 Model Simulations
AU: * Gong, G
EM: gg2138@columbia.edu
AF: Columbia University, Department of Earth and Environmental Engineering, 918 Mudd 500 West 120 Street, MC4711, New York, NY 10025
AU: Frei, A
EM: afrei@hunter.cuny.edu
AF: Hunter College of the City University of New York, Department of Geography 695 Park Ave, New York, NY 10021
AB: Snow cover is potentially sensitive hydrologic indicator of global climate change, as it is an integrated index of a number of climatological and hydrological conditions, and also an effective climate feedback mechanism. In this study, 20th and 21st century decadal scale trends and variability in winter North American snow cover extent (NA-SCE) are investigated using coupled atmosphere-ocean general circulation model experiments participating in the upcoming Intergovernmental Panel on Climate Change Fourth Assessment Report. Significant between-model variability is found, and simulation of 20th century NA-SCE observations is generally poor, although individual ensemble members capture the magnitude of decadal scale variability. Nevertheless, two 21st century emission scenarios with realistic (moderate or significant) greenhouse gas emission rates produce consistent decreasing NA-SCE trends across all models, while one unrealistic scenario with fixed concentrations produces little or no NA-SCE trend. These results suggest that North American snow extent will probably decrease in response to global climate change, although the magnitude of the response may be nonlinear.
DE: 0736 Snow (1827, 1863)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1626 Global climate models (3337, 4928)
DE: 1630 Impacts of global change (1225)
DE: 1807 Climate impacts
SC: Hydrology [H]
MN: Fall Meeting 2005