摘要
利用１７年（１９７９～１９９５）的ＮＭＣ全球格点分析资料及从ＮＯＡＡ极轨卫星观测的地球向外长波辐射（ＯＬＲ）资料，研究了南海夏季风暴发的年际变化特征．用本文的定义标准，南海季风从１９７９年到１９９５年间暴发的平均日期是５月第４候．南海夏季风暴发前后，南海周围地区对夏季风暴发的直接影响来自南海上游７０°～９０°Ｅ的赤道西风的加强和北抬东伸，同时索马里越赤道气流的加强和阿拉伯海高压在海上消失通过影响赤道西风也间接影响到南海．其中阿拉伯海反气旋的消失可能是南海夏季风暴发的一个重要信号．南海夏季风暴发的年际变化较明显，上游赤道西风对南海夏季风的暴发及其年际变化具有重要作用．南海夏季风暴发的年际变化与ＥｌＮｉｎｏ事件有一定的联系．
Interannual variation of summer monsoon onset over the South China Sea(SCS) were studied based on the seventeen years′(1979～1995) NMC global analysis data and Outgoing Longwave Radiation(OLR) data observed from NOAA polar orbit satellites. Based on the criteria defind in this paper for the SCS summer monsoon onset, the average onset date from 1979 to 1995 was around the fourth pentad of May. During the SCS monsoon onset, the most direct impact from the vicinity of the SCS is the equatorial westerly winds in the Indian ocean through their eastward extension and northward movement. Meanwhile, there are also indirect impact of the enhancement of the Somali cross equatorial flow and the vanishing of the Ariabian high at sea, which change the equatorial westerly winds, in the SCS onset. There are quite significant interannual variation in the SCS onset. It is shown that the impact of the equatorial westerly winds in the Indian ocean on the SCS summer monsoon onset and its interannual variation is very important. It has also been found that the interannual variation of the SCS onset are closely related with the ENSO events.
出处
《应用气象学报》
CSCD
北大核心
1998年第2期129-140,共12页
Journal of Applied Meteorological Science
基金
国家教委留学回国人员科研启动基金
