影响华东地区热带气旋年频数与热带对流场的关系

利用由美国NOAA系列卫星观测的OLR资料研究了影响华东地区热带气旋年频数（记为ATC）与热带对流场的关系，结果表明两者存在密切的联系：（1）当华东地区热带气旋年频数ATC为异常偏多（少）时，ITCZ位置累积距平为正（负）值，即ITCZ位置异常偏北（南）；（2）利用OLR设计了Walker综合指数WI，该指数的强弱可以反映ATC的异常情况，即当ATC为异常偏多（少）时，walker环流圈异常强（弱）；（3）OLR距平累积量场能较好的表征ATC异常年份所对应的低纬度及中高纬地区大气环流的配置，其可以作为预测影响华东地区热带气旋年频数的强信号。

RELATIONSHIP OF ANNUAL FREQUENCY OF TROPICAL CYCLONE AFFECTING EAST CHINA AND TROPICAL CONVECTION ACTIVITY

Based on 1979-1998 monthly OLR data,the relationship of annual frequency of tropical cyclone affection East China(denoted as ATC afterward)and tropical convection activity is studied.The results show that ATC bears a close relationship to the ITCZ activity,and intensity and extension of Walker circulation as well.We also designed an index(denoted as TOLR) by term of accumulated anomaly of OLR,and the TOLR induces directly the possible mechanism of ATC and successive summer tropical circulation and mid-high latitude circulation in Northern Hemisphere.The TOLR may be a strong sign to predict ATC affecting East China.