STUDY OF INTERDECADAL INTERANNUAL VARIATION OF RAINFALL OVER MID-LOWER REACHES OF CHANGJIANG RIVER AND ITS MECHANISM

Based on the NOAA/NCEP reanalyzed data, SST from the England National Meteorological Bureau, and precipitation data and Subtropical West Pacific High parameters from the National Meteorological Center, the interactions of East-Asian summer monsoon with Mid-east Pacific SSTA are analyzed. The interactions display an inter-decadal variation feature. It is found that the East Asian meridional cell is coupled closely with the low-latitude zonal cell after 1976, which strengthens the association between East-Asian summer monsoon and Mid-east Pacific SSTA. The previous winter SSTA over the Mid-east Pacific affects the offsea SSTA in next summer, as heat sources enforce the Subtropical West Pacific High; as a result, the rainfall over the Mid-lower reaches of the Changjiang River in summer is abundant