The Eddy Transport of Atmospheric Moisture over China

Based on the computation of eddy transport of atmospheric moisture by using the balloon sounding data collected from 149 meteorologic stations in 1983, some new findings for the feature of eddy transport over the territory of China have been obtained: (1) The routs of eddy transport flux present meridionality, the general direction of eddy transport is similar to that of the moisture gradient tranports atmospheric moisture to arid region in the northwest of the country from its southeast. The phenomena are of significant importance to provide and maintain the atmospheric moisture over the inland region in northwest China. (2) The eddy transport is active especialy in middle latitude zone (30°～40°N) of China, some divergence and convergence centers of eddy transport flux are available and the location of the center varies with different month and is closely related to the places of high precipitation. (3) The mainland of China shows a region with eddy vapour source in winter month and eddy vapour sink in summer month. 88% of eddy transport of atmospheric moisture enters China in the south and 55% and 40% leave China from the north and the east boundries. The exchange of atmospheric moisture by means of eddy transport between regions is considerable. (4) The contribution of eddy transport to total transport of atmospheric moisture is important, for example, the amount of atmospheric moisture by means of eddy transport from Yangtze River basin to north China is more than 90% of the total atmospheric moisture transport.