摘要
利用常规气象观测资料、NCEP 1°×1°逐6 h再分析资料、多普勒雷达资料和柳州市自动站雨量资料,对2020年8月20日由台风“海高斯”减弱停编后的残涡引起的柳州市暴雨天气过程进行诊断分析。结果表明:(1)西风槽和副高位置共同影响了“海高斯”残涡的移动路径和速度;(2)“海高斯”残涡影响柳州的过程中同时满足了条件不稳定和条件对称不稳定条件,位涡扰动有利于低层涡旋的维持,湿位涡分布对强降雨落区有较好的指示意义;(3)“海高斯”残涡影响柳州市暴雨的水汽输送通道由两支气流组成,一是“海高斯”残涡东部环流中的偏南气流与副高边缘偏南气流合并形成的偏南急流,二是孟加拉湾偏西气流经“海高斯”残涡气旋性绕流后形成的偏南气流;(4)层状云中镶嵌的对流性回波带随着螺旋云带向偏东方向缓慢移动而形成列车效应是柳州市大暴雨带形成的原因。
Using conventional meteorological observation data,NCEP 1°×1°reanalysis data for 6 hours,Doppler radar data and rainfall data from the automatic station in Liuzhou City,we used the data of the typhoon“Higos”to weaken and stop on August 20,2020.Diagnosis and analysis of the torrential rain process in Liuzhou caused by the residual vortex.The results show that:(1)the position of the west wind trough and the subtropical high affect the moving path and speed of the“Higos”remnant vortex;(2)the“Higos”remnant vortex satisfies both the unstable conditions and the symmetrical conditions in the process of affecting Liuzhou Under unstable conditions,the potential vorticity disturbance is conducive to the maintenance of low-level vortices,and the distribution of wet potential vortices has a good indication of the strong rainfall area;(3)The“Higos”residual vortex affects the water vapor transport channel of the rainstorm in Liuzhou City by two airflows.The composition of the tributary airflow is the southerly jet stream formed by the combination of the southerly airflow in the eastern circulation of the“Higos”remnant vortex and the southerly airflow at the edge of the subtropical high;The southerly airflow formed later from Bangladesh west airflow;(4)The convective echo belt inlaid in the stratiform cloud moves slowly to the east with the spiral cloud belt to form a train effect,which is the reason for the formation of the heavy rain belt in Liuzhou.
作者
苏小玲
邹颖俊
赖锡柳
SU Xiao-ling(Liuzhou Meteorological Bureau,Guangxi,Liuzhou,Guanxi 545001)
出处
《农业灾害研究》
2021年第2期110-112,115,共4页
Journal of Agricultural Catastrophology
基金
广西区气象局气象科研计划项目(桂气科2020M10)
广西自然科学基金项目(2020JJB150031)。
关键词
台风残涡
暴雨
湿位涡
Typhoon residual vortex
Heavy rain
Wet potential vortex
