中文摘要：

本文分析华南夏季风降水（P_（SM））与热带气旋降水（P_（TC））在年际和年代际尺度上的物理联系,结果表明：在年际变化上,华南P_（SM）与P_（TC）呈显著负相关。南海-西北太平洋的气旋性涡度和相对湿度增加以及垂直风切变减弱,有利于更多的热带气旋生成,从而使得华南P_（TC）增加。同时异常增暖的赤道中太平洋SST和异常偏冷的北印度洋SST会激发南海-西太平洋异常气旋,加之中国东部-日本异常反气旋的作用,使得华南P_（SM）减少。在年代际尺度上,华南P_（SM）与P_（TC）呈显著正相关,在1990s初华南P_（SM）与P_（TC）明显增加。其中,南海生成的热带气旋对华南P_（TC）年代际增多有重要贡献。前期冬春季西太平洋持续异常偏暖的SST会通过垂直环流的作用引起热带印度洋SST增暖并持续到夏季,之后偏暖的热带印度洋SST又反馈作用于西北太平洋异常反气旋,使得华南P_（SM）增加。1990s初南海夏季风爆发年代际偏早,促使华南上空的大气显热源从5月持续增加至夏季,从而有助于东亚副热带夏季风的增强和华南P_（SM）增加。

英文摘要：

This study investigates the relationship between tropical cyclone-induced precipitation（P_（TC）） and summer monsoon-induced precipitation（P_（SM）） in southern China（SC） during June-August.The spatial patterns of the first interannual mode are uniform in sign over SC,with positive anomalies for P_（TC） and negative anomalies for P_（SM）.The background of an increase in cyclonic vorticity,an increase in RH,and a decrease in vertical wind shear over the South China Sea（SCS）-western north Pacific（WNP） provides favorable conditions for more TC genesis.The positive equatorial central Pacific SST anomaly and negative North Indian Ocean SST anomaly contribute to the anomalous cyclone over the SCS-WNP,which causes decreasing P_（SM） in SC together with an anomalous anticyclone over eastern China-Japan.By contrast,whilst the spatial patterns of the first interdecadal mode are also uniform in sign over SC,there are positive anomalies for both P_（TC） and P_（SM）.The first interdecadal principal component features significant positive correlation with the number of TCs forming in the SCS.There is a significant increase in P_（TC） and P_（SM） after early 1990 s.A positive tropical Indian Ocean（TIO） SST anomaly persists from the preceding winter to summer.During the preceding winter and spring after the early 1990 s,a positive western Pacific SST anomaly can result in TIO SST warming through vertical circulation.Then,the positive TIO SST anomaly triggers an anomalous WNP anticyclone and contributes to the interdecadal increase in SC P_（SM） in the succeeding summer.The persistent heating source over SC from May to summer related to an earlier onset of the SCS monsoon may strengthen the East Asian subtropical summer monsoon.