HR: 1330h
AN: H12B-1004    [PDF]
TI: How do summer precipitation variability correlate with pre-summer soil moisture variations in U.S.?
AU: * Wu, W
EM: wwu@eas.gatech.edu
AF: Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332-0340 United States
AU: Dickinson, R E
EM: robted@eas.gatech.edu
AF: Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332-0340 United States
AB: The relative importance of the land and ocean impacts on U.S. precipitation changes with seasons and the influence of the land surface is the strongest during the warm season. As a major memory mechanism of the land surface, soil moisture has typical decay time of 2-3 months over U.S. continent, suggesting that the impact of such persistence of soil moisture on precipitation could be on seasonal timescales. The variability of U.S. summer average precipitation displays strong geographical dependence with large variability in the southeastern United States. The covariance of the U.S. summer mean precipitation with pre-summer soil moisture conditions is examined in this study using the singular value decomposition (SVD) method. The 40-year historic monthly data of precipitation and soil moisture generated by a multi-layer soil model coupled with a climate model are used to perform the SVD analysis. The well correlated expansion coefficients of SVD dominant modes indicate a significant association between summer precipitation pattern and pre-summer soil moisture variation.
DE: 1833 Hydroclimatology
DE: 1854 Precipitation (3354)
DE: 1866 Soil moisture
DE: 3322 Land/atmosphere interactions
SC: Hydrology [H]
MN: 2003 Fall Meeting