四川盆地夏季一次特大暴雨水汽特征

Water Vapor Characteristics of A Heavy Rainstorm in Summer in Sichuan Basin

利用四川省5001站气象资料、全球同化系统(GDAS)资料,NCEP再分析资料,基于拉格朗日混合单粒子轨道模型(HYSPLIT4),分析了2020年8月14~17日四川盆地西部特大暴雨的水汽输送情况。结果表明:2020年8月14~17日四川盆地特大暴雨存在明显日变化,夜间降水显著,共出现4次峰值。特大暴雨初期水汽主要来自于孟加拉湾,随着降水过程的持续,阿拉伯海东部、孟加拉湾南部及泰国湾的水汽源源不断地向盆地西部输送。定量分析不同水汽源地的贡献可知孟加拉湾的水汽占主导地位,阿拉伯海次之,泰国湾的水汽贡献最低。

This paper analyzed the water vapor transportation of the heavy rainstorm in western Sichuan Basin during August 14-17,2020 by using meteorological data from a weather station 5001 in Sichuan Province,the global data assimilation system(GDAS),and the reanalysis data from national centers for environmental predication(NCEP).The Lagrange mixed single particle orbit model(HYSPIT4)is used in the analysis.The analysis results show that the heavy rainstorm has obvious diurnal variation,and the precipitation at night is severe with 4 peaks.In the initial stage of the heavy rainstorm,the water vapor mainly came from the Bay of Bengal,and with the precipitation event continues,the water vapor from the eastern Arabian Sea,the southern Bay of Bengal and the Gulf of Thailand was continuously transported to the Sichuan Basin.According to the quantitative analysis of the contribution of different water vapor sources,the Bay of Bengal was the dominant water vapor source,followed by the Arabian Sea,and the Gulf of Thailand was the lowest.