影响我国热带气旋活动的气候特征及其与太平洋海温的关系

CLIMATIC FEATURES OF THE TROPICAL CYCLONE INFLUENCING CHINA AND ITS RELATIONSHIP WITH THE SEA SURFACE TEMPERATURE IN THE PACIFIC OCEAN

利用1956~2000年的热带气旋(简称TC,下同)资料对影响我国TC活动的气候特征进行了初步的统计分析,结果发现影响我国的TC活动具有明显的阶段性特征,1960年代影响我国的TC数明显偏少,而后进入偏多期,1990年代又相对偏少。影响我国的TC强度多集中于980~999 hPa,华东的闽、浙一带TC登陆比华南晚,但强度较大。在此基础上通过对影响我国的TC年个数与太平洋海温场进行相关分析,发现两个相关较密切的区域: 西太平洋暖池(120~150 E, 10~20 N)正相关区、赤道中东太平洋(180 ~90 W, 10 S^5 N)负相关区,这两个相关区具有较好的持续性。进一步分析影响我国的TC在El Ni駉年与La Ni馻年的气候特征发现,El Ni駉年影响我国的TC数较少,但强度较大,La Ni馻年则相反,影响我国TC多年和少年对应的太平洋海温距平分布形势分别与La Nia年和El Nio年的海温距平分布形势类似。

The climatic features of the tropical cyclone (TC) influencing China have been analyzed by using the TC data from 1956 to 2000. The results show that there exist different features of the TC activities influencing China in different periods. In 1960抯, there were relatively fewer TC influencing China and, then more TC affecting China in the following 1970 and 1980s, and another fewer TC period appears in 1990s. The central TC pressures are about 980~999 hPa, in which the landing TCs in east China are more intense than that in south China. Moreover, it is also found that there exist two closely correlated areas with high persistence between the annual TC numbers influencing China and the SST anomalies in the Pacific ocean, i.e. the western Pacific pool region(120~150 E, 10~20 N)with positive correlation and the central and eastern equatorial Pacific (180~90 W, 10 S^5 N) with negative correlation. The climatic features of the influencing TC in El Nio and La Nia years are also analyzed. In El Nio year fewer but more intense TCs influence China, but in La Nia year more but weaker TCs affect China. The Patterns of the SST anomalies in the Pacific ocean in more TC years and fewer TC years are similar to those in La Nia years and El Nio years.