9403强热带风暴致洪暴雨Tbb特征分析

TBB CHARACTERISTIC ANALYSIS OF HEAVY RAINFALL CAUSING FLOOD IN STRONG TROPICAL STORM 9403

本文利用1经纬度间隔Tbb资料分析1994年6月9～10日皖、赣致洪暴雨过程的成因。结果指出，登陆北上的9403强热带低压同西风带降水系统相互作用造成了这场大暴雨过程。南北低值系统的叠置使降水系统结构发生变化，在两云系接合处产生强对流云团，导致降雨量陡增。分析还表明这场致洪暴雨的发生与下面三个因素有关：1、南、北两云系都有相当尺度和强度；2、南来云团有来自ITCZ和西南地区云系的水源补充；3、不断有西风带短波系统东移影响。

In this paper, a case of heavy rainfall causing flood over Anhui and Jiangxi in summer of1994 was analysed with the aid of Tbb data- Results show that the interaction between strongtropical storm 9403 and westerlies rainfall system leads to cause this heavy rainfall. Whennorth cloud band overlapped with tropical low cloud cluster, the structure of rainfall systemmay be changed. The strong convective cloudcluster that results in enhancement of rainfalloccurred in the overlapping place. This analysis also points out that the heavy rainfall causingflood is closely related to following three factors: 1. both of south and north cloud bandshave enough intensity and space scale; 2. the southerlies cloud cluster has wet source supple-ment which colnes from ITCZ and cloud band located in southwest; 3. the heavy rainfallcloud band was continuously enhanced by mergence of westerly short wave trough cloudbands.