Anomalies of the South China Sea summer monso on and their influence on the atmospheric and oceanic elements over the South China Sea as well as its adjacent regions

Based on the comparative analysis of the major air-sea elements over the South China Sea (SCS) and its adjacent regions during the anomalous years of South China Sea summer monsoon (SCSSM), the fundamental results were obtained.In the summer of the strong SCSSM year, the westerly in the low level and easterly in the upper level over the middle and southern part of the SCS enhanced, the cyclonic anomaly circulation existed over the northern part of the SCS, the ascending motions strengthened.Correspondingly, the convections and precipitation enhanced over the SCS and the coastal areas of China, whereas the precipitation decreased over the middle and lower reaches of the Changjiang River valley.While in the weak SCSSM year, the distributions of the above mentioned meteoro logical elements appeared nearly different.In the Strong SCSSM year, the position and strength of the subtropical high over the western Pacific Ocean was obviously farther east and weak than normal.Correspondingly the distributions of the convections, precipitation, and the atmospheric heat sources over the SCS and its adjacent regions between the strong and weak SCSSM year appeared quite different.The most significant difference was located at the SCS and its adjacent regions.In the strong SCSSM year, the obvious enhanced heat sources appeared over the regions from the Bay of the Bengal to the area to the east of the Philippines.Whereas in the weak SCSSM year, the heat sources over these regions weakened.Also, the distributions of the sea surface height, ocean circulation, sea surface temperature and so on which reflected the ocean conditions were apparently different between the strong and weak SCSSM year.As an important forcing factor, sea surface temperature not only plays an important role in the formation of the monsoonal circulation, but also was greatly affected by the monsoon anomalies.Further, it would make a significant impact on weather and climate over the local region.