影响中国台风的气候特征及其与环境场关系的研究

分析了影响中国台风的气候特征，结果表明：5-11月是影响台风活跃季节，7-9月为集中期；1951—2004年影响台风的频数变化呈减少趋势，1970年代后期明显减少，近十年是影响台风频数最少的时期；近50余年影响台风中超强台风的频数减少显著；台风生成的源地有明显的年代际变化，1960年代-1970年代生成台风位置偏东、偏南，1980年代以后转为偏北、偏西。同时分析了影响台风与北太平洋海温及东亚夏季风环流的关系，认为北太平洋海温的年代际和年际变化与影响台风关系密切；影响台风偏多年和偏少年，其环流形势截然不同。

STUDY ON CLIMATIC CHARACTERISTICS OF CHINA-INFLUENCING TYPHOONS AND THE INTERRELATIONS BETWEEN THEM AND THEIR ENVIRONMENTAL FACTORS

Climatic characteristics of China-influencing typhoons(CIT) were analyzed in this paper.Main characteristics include:(1) CIT season is May-November,especially from July to September.(2) Frequency of the CIT shows a decrease trend during 1951~2004,especially after the late period of the 1960s.(3) Strong CIT also shows an obvious decrease trend.Meanwhile,there exist obvious interdecadal variations in the CIT genesis,being more southward and eastward than normal in 1960s~1970s,and more northward and westward than normal in the 1980s.In addition,the interrelations between CIT and its environmental factors show that CIT has close relationships with sea surface temperature and East Asian summer monsoon;the structure of the circulations in frequency CIT years is much different from that in infrequent CIT years.