Interdecadal variation of precipitation pattern and preliminary studies during the summer of late-1990s in East Asia

Based on the analyses of monthly precipitation, National Centers Environmental Prediction/University Corporation for Atmospheric Research reanalysis dataset, and 2°×2° sea surface temperature (sst) data of extended reconstructed sea surface temperature during 1983-2011, we discuss the interdecadal variations of precipition around late-1990s in East Asia, the contributions of the atmospheric internal dynamic processes, and the extra-forcing factors such as sst that presents interdecal characteristics corresponding to the results obtained by using regress analysis. The results show that the interdecadal variations of the summer rainfall over Northern East Asia around late-1990s were more obvious than over Southern East Asia, and the summer rainfall over Southern East Asia experienced a notable interdecadal change around early-1990s and early-2000s. The summer geopotential height at 500 hPa, the summer wind at 850 hPa, the summer U-wind at 200 hPa, the water vapor transportation field, the index of EAP and EASM all have the notable characteristics of the interdecadal variations, which further validate the interdecadal change of precipition of late-1990s from the angle of the atmospheric internal dynamic process. At the same time the sea surface temperature interdecadal anomalies of North Pacific and West Pacific may also be one of the important reasons for causing the interdecadal change over East Asia of the late-1990s.