台风突然加强与环境场关系的气候分析

THE CLIMATIC ANALYSIS OF THE RELATIONSHIP BETWEEN THE EXPLOSIVE DEVELOPMENT OF TYPHOON AND ITS ENVIRONMENT FLOW FIELD

主要用气候统计方法，按不同标准对１９４９—１９９２年影响我国（进入防线）的西太平洋台风资料进行过滤分析。确定台风突然加强的标准。在此基础上对它们进行分类，给出各类的时空分布特点及高低层平均环境场。得出的结论是（１）影响我国的突然加强的台风主要出现在每年的７—１０月，并集中在南海中部，东海出现的个例甚少。（２）按中心气压和近中心的最大风速变化的先后，突然加强台风可分为三类，第三类与第一、二类高低层的平均环境场不相同，台风突然加强主要受低纬环流和天气系统的影响，中高纬的西风带系统作用不大。

Using the method of climatic statistics,the filtering analysis is made for the data of typhoon occuring in the western Pacific(affecting China's Mainland)during 1949-1992,and their objective criterion of explosive development is determined. On this bases,their space-time distribution and average environment flow field in lower and upper troposphere level are given.The results are as follows.(1) The explosive intensification of typhoon mainly occurs in the Southern China Sea from July to September every year.It is rare in the East China Sea.(2)According to variation of central pressure and maxiam velocity near the centre,the explosive development may be classfied into three patterns.In the lower tropospheric level,the average environment flow field in the third pattern are different from the other.Their explosive development mainly results from the circulation and weather systems in the low latitude.The role of those in middle-high latitude does not have much importance.