四川盆地东北部地区一次暴雨天气过程分析  

Analysis of A Rainstorm Weather Process in Northeast Sichuan Basin

作　　者：龙俊天 廖文超 李晓容[1,2,3] Long Jun-tian(Nanchong Key Laboratory for Strong Weather Research in Northeast Sichuan,Nanchong,Sichuan 637000)

机构地区：[1]川东北强天气研究南充市重点实验室,四川南充637000 [2]强天气监测预报预警技术研究创新团队,四川南充637000 [3]四川省南充市气象局,四川南充637000

出　　处：《农业灾害研究》2023年第5期118-121,共4页Journal of Agricultural Catastrophology

摘　　要：利用常规天气观测资料、ERA5的0.25°×0.25°再分析资料、新一代多普勒天气雷达、FY-4卫星云图资料对2022年7月21—22日发生在四川盆地东北部的一次强降雨天气过程进行了诊断分析。研究表明:(1)贝加尔湖低槽和高原低槽合并增强后东移,与四川盆地700 hPa、850 hPa切变辐合系统、低空急流配合,共同构成了此次暴雨的大尺度环流形势,十分有利于暴雨的发生;(2)此次暴雨持续时间短,降雨效率高,低层高比湿、显著的上升运动、深厚的暖云以及中等偏强且呈狭长分布的对流有效位能是降雨效率高的关键原因;(3)低空急流为强降雨区域提供了充足的水汽和能量,以及显著的上升运动;(4)物理量指标变化能很好地反映各个阶段降雨强度变化,对预报有指示意义;(5)过程中云团的初生、发展、移出与降雨实况对应良好,强降雨期间雷达回波具有明显的后向传播和列车效应。Presented a diagnostic analysis for a heavy rainfall weather process that occurred in the northeastern Sichuan basin on July 21-22,2022 used conventional weather observation data,0.25°×0.25°reanalysis data of ERA5,new generation Doppler weather radar,and FY-4 Satellite Data.The study showed that:(1)The Baikal trough and the plateau trough merged and strengthened and then moved eastward,and cooperated with the 700 hPa and 850 hPa shear convergence systems and low-level jet in the Sichuan basin,which together constituted the large-scale circulation situation of the storm and was very favorable to the occurrence of the storm;(2)The duration of the storm was short,the rainfall efficiency was high,the low-level high specific humidity,significant upward motion,deep warm clouds and moderately strong and narrowly The low-level high specific humidity,significant upward motion,deep warm clouds and moderately strong and narrowly distributed convective effective potential energy are the key reasons for the high rainfall efficiency;(3)The rapid lowlevel flow provides sufficient water vapor and energy for the area of heavy rainfall,as well as significant upward motion;(4)The changes of physical quantity indicators can well reflect the changes of rainfall intensity in each stage,which is indicative for forecasting;(5)The initial generation,development and migration of cloud masses during the process correspond well with the actual rainfall,and the radar echoes during the heavy rainfall have obvious backward propagation and train effect.

关 键 词：暴雨 诊断分析 降水效率 低空急流 

分 类 号：P458.121.1[天文地球—大气科学及气象学]