A Composite Study of the Influence of SST Warm Anomalies over the Western Pacific Warm Pool on Asian Summer Monsoon
Jin Zuhui and Chen Jun (Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029)
Based on NCEP reanalyzed data, a composite analysis of general circulations and the SST anomalies over the western Pacific warm pool and their statistical verification through the singular val-ue decomposition (SVD) method are made to describe the best coupled patterns between SST and sum-mer monsoon in East Asia, The results show that a very strong anticyclone deviation circulation occurs in the lower troposphere over the western Pacific Ocean along with positive SST anomalies of the warm pool. On the one hand, the anticyclone deviation circulation makes the easterly wind to the south of the subtropical high become stronger and extend to the Indo-China Peninsula, which affects the develop-ment of southwest monsoon in the tropical area of Southeast Asia. On the other hand, the anticyclone deviation results in stronger southerly wind to the southwest of the subtropical high, so the summer monsoon of the subtropical areas, especially the eastern part of China, become much stronger, The ana-lyses of S VD show that there exist two best coupled patterns between SST and zonal, meridional wind, which indicates that the SST anomalies of whole warm pool can affect the general circulation of East Asia, and so can the heterogeneous distribution of SST anomalies.