The Interdecadal Variation and Physical Mechanism for the Summertime Water Vapor Transport in Northern East Asia in the Late 1990s

Time water vapor transport over the northern East Asia have been analyzed using various datasets of precipitation, atmospheric circulation and sea surface temperature (SST) for the period of 1983 to 2011. The influence of preceding winter North Atlantic SST on the summertime water vapor transport and atmospheric circulation in northern East Asia are investigated. Results show that the decadal variability of summertime integrated water vapor transport, which is caused by changes in zonal water vapor, is similar to that of precipitation over northern East Asia in the late 1990s. Moreover, the decadal change is more significant along the western boundary than in the eastern boundary of the study region. A significant correlation is found between preceding winter North Atlantic SST and 500 hPa geopotential height, 850 hPa wind and specific humidity in the summer. In the late 1990, SST changes from anomalously cool to anomalously warm in the winter and the warm SST anomaly persists into the following summer. The summer North Atlantic SST anomaly generates an Atlantic-Eurasia (AEA) teleconnection structure that is across the North Atlantic and the middle-high latitude of Eurasia during the corresponding period, and further influences the summertime water vapor transport over northern East Asia.