气象科学2025，Vol.45Issue(3)：320-330,11.DOI:10.12306/2023jms.0024
中低纬度系统相互作用引发极端降水的中尺度系统结构分析
Mesoscale system structure of the extreme precipitation triggered by the interactions of mid-low latitude system
摘要
Abstract
The Doppler radar data,the automatic meteorological stations,the wind profiles data combined with the NCEP/NCAR 1 °×1 ° reanalysis data and dual Doppler inversion of wind fields were used to analyze the mesoscale dynamical structure and evolution during the extreme rainstorms caused by the interaction of mid-low latitude systems,taking Typhoon Lekima as an example,results show that:(1)The mid-alpha scale convergence zone induced by the shear between the southeasterly flow of the typhoon circulation and the northerly flow of the westerly trough is the key mesoscale system directly induced the rainstorm;(2)The enhanced southeast jet trigger initial convection,followed by enhanced high-altitude jet stream,which deepen the mesoscale convergence zone,and the variable pressure winds caused by its propagation superimpose with the southeast jet and open access with the southward jet in front of the trough,forming a long warm and humid belt from the sea,providing abundant water vapor and unstable energy;(3)Three-dimensional fine wind fields from dual Doppler radar inversions show that initial convection is triggered by discontinuous southeasterly wind pulses at heights of 1 to 4 km with wind speeds greater than 16 m·s-1;when the low-level northeasterly flow thickens to a height of 4 km,the increase in wind vertical shear leads to an increase in precipitation intensity of more than 20 mm·h-1;(4)Cold air sinks from the upper level of the weakened westerly trough and invades the lower level to the southeast,which is an indispensable condition for shear formation,strengthening and maintaining for a long time,promoting upward motion and convection strengthening,increasing vertical wind shear and causing precipitation increase,which is an important factor for the extreme rainstorm.关键词
中低纬度系统相互作用/中α尺度系统/台风"利奇马"/冷空气Key words
mid-low latitude system interactions/mid-alpha scale system/Typhoon Lekima/cold air分类
天文与地球科学引用本文复制引用
李君,邹瑾,高留喜,胡晓琳,毕陟,邱粲,贾瑞..中低纬度系统相互作用引发极端降水的中尺度系统结构分析[J].气象科学,2025,45(3):320-330,11.基金项目
山东省自然科学基金资助项目(ZR2023MD001) （ZR2023MD001）
山东省气象局科研资助项目(2023SDQXZ04) （2023SDQXZ04）
淮河流域气象开发研究基金资助项目(HRM202416) （HRM202416）
山东省气象局科研资助项目(2022SDYD14) （2022SDYD14）
