夏季越赤道气流对南海季风及华东旱涝的影响

THE EFFECTS OF CROSS-EQUATORIAL CURRENTON SOUTH CHINA SEA MONSOON ONSET ANDDROUGHT/FLOOD IN EAST CHINA

应用NCEP/NCAR全球再分析资料和NOAA卫星接收的HIRS-Tb12等资料,研究了东半球夏季越赤道气流的气候学特征、越赤道气流对南海季风爆发的影响、越赤道气流与海温场的联系、以及对华东地区旱涝的影响。得出:南非高压、南印度洋高压和澳大利亚高压对越赤道气流的维持和强度变化具有重要的作用;北太平洋海温场对越赤道气流的强弱也具有重要的影响:5、6月份索马里越赤道气流偏强,则南海季风爆发偏早:华东地区夏旱年越赤道气流显著偏强,雨涝年呈强弱相间的变化。

The climatic characteristics of cross-equatorial current and the relations between the sea surface temperature on the northern Pacific Ocean and the cross-equatorial current have been researched by using NCEP/NCAR data and HIRS-Tb12 data observed from NOAA satellites. The effect characteristics of cross-equatorial current on South China Sea monsoon onset and drought/flood in east China have also been analyzed. The results show that there is great influence of the South African high, south Indian Ocean high and Australia high on cross-equatorial current. The sea surface temperature also makes a notable impact on cross-equatorial current. The South China Sea monsoon sets in earlier when the Somali cross-equatorial current is stronger in May or June. The cross-equatorial current is notably strengthened during the drought year and its intensity is changeable during the flood year.