CHARACTERISTICS OF MOISTURE TRANSPORT IN SUMMER OVER THE TIBETAN PLATEAU

We use a Gauss filter,EOF analysis,synthetic analysis,correlation analysis and other methods to analyze the characteristics of moisture transport in summer over the Tibetan Plateau in recent 50 years based on the NCEP/NCAR mean daily and monthly reanalysis data.The results showed that moisture transport in summer over the Tibetan Plateau in the layers had its own uniqueness.Moisture transport of the South China Sea and the eastern region of the Tibetan Plateau had an important impact on China mainland high-altitude water vapor,the water vapor of the Southern China and the middle and lower reaches of the Yangtze River on high altitude from the South China Sea area and the water vapor of the North China and the middle east of China on high altitude from East Central Plateau.The mean circulation transport and moisture transport had the same characteristics approximately.The longitudinal of transient eddy transport was very strong on the Tibetan Plateau,which was much stronger than its zonal transport.The mean circulation transport was one magnitude larger than transient eddy transport.The mean circulation transport influenced mainly moisture content of the eastern and southwestern regions in China,while the transient eddy transport influenced the north of China.The EOF analysis of the moisture transport showed that,EOF1 reflected the characteristics of the northwest wind transport that before about1976 were positive anomaly,but weakened significantly after 1976.EOF2 reflected the characteristics of southwest wind transport that after about 1980 were positive anomaly,while weakened at other times.