南海夏季风爆发的大气热源特征及其爆发迟早原因的探讨  

CHARACTERISTICS OF ATMOSPHERIC HEAT SOURCE ASSOCIATED WITH THE SUMMER MONSOON ONSET OVER THE SOUTH CHINA SEA AND THE POSSIBLE MECHANISM RESPONSIBLE FOR LATE OR EARLY ONSET OF THE MONSOON

作　　者：蓝光东[1] 温之平[1] 贺海晏[1] 

机构地区：[1]中山大学季风与环境研究中心/大气科学系,广东广州510275

出　　处：《热带气象学报》2004年第3期271-280,共10页Journal of Tropical Meteorology

基　　金：国家自然科学基金资助项目40275026;国家重点基础研究发展规划项目G1998040900第一部分共同资助

摘　　要：利用ECMWF(1979～1993年)的再分析资料分析了南海夏季风爆发前后的大气热源演变特征,并由此确定了南海夏季风爆发的大气热源判据.将该判据应用于1979～1993年总共15年的平均场,可判定南海夏季风平均于28候(5月第4候)爆发.而且,对于逐年南海夏季风爆发,该判据也有较好的指示意义.本文还发现,南海夏季风爆发的迟早与4月份40 (S纬圈平均的大气热源垂直积分<Q1>有着非常密切的联系,由此得到的南海夏季风爆发时间的前期判定指标能较好地判断南海夏季风的爆发时间.南海夏季风爆发迟早的原因,及其与4月份40 (S纬圈平均<Q1>之间的联系,可以通过南北半球哈得莱环流的变化得到解释.Characteristics of atmospheric heat source associated with the summer monsoon onset in the South China Sea (SCS) are studied using ECMWF reanalysis data from 1979 to 1993. A criterion of the SCS summer monsoon onset is defined by the atmospheric heat source. Applying this criterion to the 15-year (1979～1993) mean field, the onset of the SCS summer monsoon occured in the fourth pentad of May. And this criterion can also give reasonable results for the onset time of the SCS summer monsoon on a year to year basis. In addition, pretty high correlation has been found between the onset time of the SCS summer monsoon and the zonnal mean vertically integrated heat source <Q1>t 40 S in April. The causes for the late or early onset of the SCS summer monsoon and the close relationship between the onset time and the zonnal mean vertically integrated heat source <Q1>t 40 S in April might be explained by the variations in intensity of the Hadley circulation.

关 键 词：南海夏季风爆发 大气热源 哈得莱环流 

分 类 号：P425.4.2[天文地球—大气科学及气象学]