0505号台风“海棠”灾害的初步诊断研究

Diagnose and Research on Typhoon Disasters Caused by 0505 Typhoon Haitang

0505号台风“海棠”(Haitang)是一个范围广、强度大、路径复杂的台风,在其生命史的各个阶段表现出不同的特征。该台风具有很强的破坏力,使我国许多地区遭受严重灾害。在对台风灾害和环流背景分析的基础上,利用Q矢量和螺旋度等诊断方法,对该台风在浙闽地区造成强降雨的成因作了初步的研究。研究表明,台风外围螺旋云带、台风密蔽云造成台湾省和大陆东南部地区强降雨,其外围东南急流中的云团也引发了强降雨,而台风减弱后的残留低压与西风带系统相互作用在华北区产生了强对流天气和强降雨。通过对该台风登陆前后Q矢量辐合辐散情况的诊断可用来判断当时的垂直运动分布,而对螺旋度的分析,发现该台风的螺旋雨带在低层相对螺旋度场上反映为正的大值中心。

The 0505 Typhoon Haitang has extensive confines, strong intensity ,intricate trace and different characteristics in its different stages. It caused very severe damage breakage and grave loss in China. Based on the analysis on the typhoon disasters and general circulation, this paper researches the basic reasons of heavy rain in Zhejing and Fujian provinces by using diagnosing methods such as Q vector and helicity, etc. The helicoidal cloud cinctures within typhoon＇s periphery, close-grained cloud cinctures near its center caused heavy rain in Taiwan and southeastern China. And cloud agglomerates existing in the southeast jet in its periphery also made strong precipitation. Furthermore, the interaction between the typhoon＇s remnant low-pressure and the west wind systems brings strong convective weather phenomena and heavy precipitation in northern China. In the fore-and-aft typhoon landfalling, the convergence or divergence of Q vector can be used to estimate vertical motion field. Moreover, the typhoon＇s helicoidal cloud cinctures behaved as a positive maximum center on the lower level relative helicity field by means of analyzing the helicity.