EQUATORIAL EASTERN PACIFIC SST AND ANALYSIS ON CAUSES OF SUMMER FLOODS/DROUGHTS IN THE CHANGJIANG AND HUAHE RIVER BASIN

The power spectrum and correlation analysis is made of the relation between SST on the equatorial East Pacific and the West Pacific warm pool and summer precipitation over the Changjiang and Haihe River basins. The results indicate that summer precipitation over the Changjiang and Haihe River basins is greater when El Nino warming occurs in autumn or winter and less when ENSO develops in spring or summer. The comparison and analysis is conducted, by using two cases, of the characteristics of the abnormal stream fields of ENSO events warming in different seasons and the impact on the precipitation over the Changjiang and Haihe River basins. ENSO events warming in different seasons, corresponding to the certain stages of circulation adjustment over the tropic Pacific region, are the main cause of summer monsoon variation as well as weather and climate abnormality in summer in East Asia.