广西东南部"海葵"残涡特大暴雨成因分析
Analysis of the Causes of Torrential Rainfall Event Associated with the Residual Vortex of"Haikui"in Southeastern Guangxi
陆秋霖 1林确略 1李秀昌 1韦荣 1张容菁 1陈明璐1
作者信息
摘要
利用各种常规气象资料、ERA5 再分析资料等对 2023 年 9 月"海葵"残涡造成广西东南部特大暴雨的成因进行分析.结果表明:(1)华南地区处于 200 hPa南亚高压东南侧的辐散区,500 hPa副热带高压减弱东退,西风槽东移引导弱冷空气南下,有利于"海葵"残涡长时间维持在广西东南部上空,冷暖空气交汇激发对流,产生特大暴雨.(2)低层季风气流加强,在广西东南部有西南风和东南风的辐合,充足的水汽输送到"海葵"残涡东侧堆积,中高层辐散、低层辐合的良好配置促进了上升运动发展,为特大暴雨的发生提供有利条件.(3)对流单体后向传播形成"列车效应",回波质心低,抬升凝结高度低,以高效率的暖云降水为主,超低空急流对强降水的出现具有指示作用.
Abstract
Utilizing various conventional meteorological data and ERA5 reanalysis data,an analysis was conducted on the causes of the extraordinary torrential rain in the southeastern part of Guangxi in September 2023,induced by the remnant vortex of"Haikui".The results indicate:(1)The South China region was located on the divergent side of the 200 hPa southeastern South Asian High.At 500 hPa,the subtropical high weakened and retreated eastward,while the westerly trough shifted eastward,guiding weak cold air to move southward.This was conducive to the prolonged presence of the"Haikui"remnant vortex over southeastern Guangxi,where the convergence of cold and warm air triggered convection,resulting in extraordinary torrential rain.(2)The low-level monsoon flow strengthened,with convergence of the southwest and southeast winds in southeastern Guangxi.Ample moisture transport to the eastern side of the"Haikui"remnant vortex accumulated,and the favorable alignment of mid-to-upper level divergence with low-level convergence promoted the development of upward motion,providing favorable conditions for the occurrence of extraordinary torrential rain.(3)The backward propagation of convective cells formed a"train effect",with low echo centroids and lifting condensation heights,predominantly characterized by efficient warm cloud precipitation.The ultra-low-level jet stream played a certain indicative role in the emergence of heavy rainfall.
关键词
残涡/特大暴雨/冷空气/季风/水汽Key words
residual vortex/extremely heavy rainfall/cold air/monsoon/water vapour引用本文复制引用
基金项目
广西气象科研青年人才培养项目(桂气科2022QN04)
中国气象局复盘总结专项项目(FPZJ2024-097)
广西科技厅重点研发计划(桂科AB24010085)
出版年
2024
国家科技期刊平台
NSTL
万方数据