2008年6月广东省连续性暴雨的成因

利用NCEP/NCAR再分析资料,分析2008年6月12-18日广东省连续性暴雨过程的环流背景及成因。结果表明：在中纬短波槽和南支槽活跃的环流形势下,低层低涡切变线和西南急流引起的强烈上升运动是这次广东省连续性暴雨的触发因子。孟加拉湾和西北太平洋的2支水汽在南海汇合,持续向华南输送暖湿空气,并由经向风场辐合形成较强的水汽辐合中心。连续性暴雨期间,华南上空异常加热源有利于其西北侧低空异常气旋性环流的维持和广东省沿海地区西南急流的稳定存在。异常偏强的水汽输送辐合和大气热源加热是这次连续性暴雨得以维持的重要原因。

Causality Analysis of the Continuous Heavy Rain in Guangdong during June 2008

Abnormal cireulation characteristics and the causes of the continuous heavy rain in Guangdong during 12 - 18 June 2008 are investigated by using NCEP- NCAR reanalysis datasets. The results indicate that the continuous heavy rain process was associated with the large - scale weather pattern, which primarily consisted of two troughs respectively located over Urals Mrs and East Asia and a ridge located over northern China. The lower level shear line and jet stream over South China contributed to the development of the heavy rainfall and severe storm in Guangdong, The lower level southwest flow from the South China Sea （ SCS ） constituted the major moisture channel and moisture convergence. The positive abnormal apparent heating source and moist sink over Guangdong forced a low - level exceptional cyclonic circulation on its northwestern part, and consequently maintained a southwesterly jet over South Eastern Guangdong, which exacerbated the magnitude of the rainfall accumulations and subsequent flooding.