0505号台风持续大暴雨成因分析

The analysis of continuous heavy rain of typhoon “Haitang”

2005年0505号(海棠)台风的外围螺旋云带长时间停留在浙江上空,造成我省连续五天的降水和东南沿海地区持续二天大暴雨的过程。本文根据降水强度资料、天气形势场、大气物理量(散度、涡度、水汽通量、水汽通量散度、比湿)、卫星云图特征等进行综合分析,发现台风强度强、范围大、维持时间长以及有较好的低层辐合、高层辐散是大暴雨产生的主要原因,两条很好的水汽输送通道为台风螺旋云带对流云发生发展和大暴雨的维持提供充足的水汽条件。本文还对登陆浙江的台风和登陆福建北部的台风在浙江降水情况进行了对比分析。

The spiral cloud bands of typhoon ＂Haitang＂ stayed above Zhejiang province for long time, which kept Zhejiang in rain for five days and the southeast coastal area of Zhejiang province in sustained heavy rain for two days. We synthetically analysed precipitation data, atmospheric circulation, physical variables and character of satellite image. It＇s found that the main causes of heavy rain are the strong intensity of typhoon, its widespreading and long life time in land with favorable low-level convergence and high-level divengence. The precipitation caused by typhoon landing in Zhejiang province and landing in Fujian province are also compared in this paper.