Relationship of the SSTA Temporal Variation in the Middle and East Equatorial Pacific in Spring and Summer to East Asia Summer Monsoon

East Asia summer monsoon has a distinct interannual variability, and the external forcing is one of main causes resulting in the interannual difference of East Asia summer monsoon, but the effect of the tropical sea surface temperature is the most prominent. Though SST is not the only factor that affects the weather and climate anomaly in China summer season, the tropical SSTA must be considered. Some previous researches only consider the influence of SSTA on East Asia summer monsoon in the different phases of warm and cold episodes. From the point of temporal variation, the study suggests a new point of view that the temporal variation of SSTA in the Middle and East Equatorial Pacific in spring-summer season has an effect on summer rainfall of China and East Asia summer monsoon. By using SSTA index of Niño1+2, 3, 4, 3.4 from 1951 to 2003, the analysis on the relationship between each of four regions temporal variation of SSTA from March to August and China summer precipitation is carried out. In the years of positive temporal variation of SSTA, there is less summer precipitation to the south of the Yangtze, North China and east part of Northwest China. The opposite situation occurred in the years with the negative temporal variation. Particularly the correlation coefficient is the highest between the temporal variation of SSTA of Niño3.4 region and summer precipitation. Thus, some further researches have been conducted regarding the temporal variation of SSTA of Niño3.4 region as a prediction signal. By means of calculating the correlation between the temporal variation of SSTA in Niño3.4 region and the vertical shear of zonal wind in East Asia, it is found that there is a significant relationship between the temporal variation of SSTA of Niño3.4 region and circulation pattern of East Asia summer monsoon. Furthermore, the composite analysis is done for the years of positive and negative temporal variation of SSTA respectively. The result shows that there are obvious differences in the 500 hPa height anomaly, 850 hPa zonal wind anomaly, 200 hPa zonal wind anomaly etc, especially to the south of the Yangtze River, South China Sea and Northeast China. The temporal variation of SSTA of Niño3.4 region in spring and summer can provide a prediction clue to the prediction of East Asia summer monsoon and the summer precipitation in China.