登陆台风变性发展与消亡的对比分析

THE EXTRATROPICAL TRANSITION ANALYSES ON TWO LANDFALL TYPHOONS

本文对0421(海马)和0311(环高)台风登陆后不同的演变过程进行了对比分析。分析表明,虽然两次台风登陆的时间和路径都很相似,但是由于环境场的形势的不同,特别是北方冷空气情况的不同,一个变性发展成为温带气旋,给江苏地区带来了大面积的降水,另一个直接减弱消失,仅在登陆点附近产生了一些降水。通过讨论锋生函数各项的性质和计算其主要项的分布特征,对变性过程进行了研究,发现台风变性初期其锋生函数中变形项起主要作用。锋生结果造成强烈的辐合上升运动,引起台风暴雨的增幅。

The different transition process of two landfall typhoons （0421（Haima） and 0311（Vamco）） was studied. By the analyses of their height, temperature and wind field features, it was found that after typhoon landfall, the 0421（Haima） typhoon went through extratropieal transition process, caused heavy rain in Jiangsu Proviee. The other one 0311（Vameo） did not go through that process and no heavy rain happened. This article tried to find the reason of the different process by the aid of frontogenesis function.