Characteristics of Persistent Anomalies of the South China Sea Summer Monsoon and Its Influences on the Global Atmospheric Circulation
南海夏季风持续异常的特征及其对全球环流的影响Ⅰ.诊断分析

The characteristics of persistent anomalies of the South China Sea Summer Monsoon (SCSM) and its relationship with atmospheric circulation are studied by using OLR and NCFP/ NCAR reanalysis data (1980-1996). Comparative analysis shows that the variation of the large scale circulation (including the subtropical high. Hadley and Walker cells), is basically contrary between the strong and weak SCSM. The persistent anomalies of SCSM not only relates to the tropical and subtropical large scale flow fields, but also reflects the adjustment of the northern extratropical cir-culation. Moreover, the response of large scale circulation in the Northern Hemisphere to the SCSM persistent anomalies is further evidenced. The contrary distribution of kinetic energy for the strong and weak SCSM, especially in their persistent anomaly period, almost covers the whole globe. The apparent heat source and moist sink illustrate a totally different features for those two periods. The intense and persistent convection resulting from strong SCSM would cause a remarkable change of heat source in the atmosphere, and then influence the vertical circulations.