青藏高原东南缘攀西一次突发性山地暴雨成因分析  

Cause Analysis of a Sudden Mountain Rainstorm in the Southeastern Margin of Tibetan Plateau

作　　者：徐金波[1] 卢萍 曾波[3,4] 吕俊杰[5] XU Jinbo;LU Ping;ZENG Bo;LYU Junjie(Panzhihua Meteorological Service,Panzhihua 617000,China;State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081,China;Institute of Plateau Meteorology,CMA,Chengdu 610072,China;Heavy Rain and Drought-Flood Disasters in Plateau and Basin Key Laboratory of Sichuan Province,Chengdu 610072,China;Liangshan Meteorological Service,Xichang 615000,China)

机构地区：[1]四川省攀枝花市气象局,攀枝花617000 [2]中国气象科学研究院灾害天气国家重点实验室,北京100081 [3]中国气象局成都高原气象研究所,成都610072 [4]高原与盆地暴雨旱涝灾害四川省重点实验室,成都610072 [5]四川省凉山州气象局,西昌615000

出　　处：《高原山地气象研究》2024年第2期40-49,共10页Plateau and Mountain Meteorology Research

基　　金：国家重点研发计划项目(2022YFC3003902);四川省自然科学基金项目(2022NSFSC0021);中国气象局决策气象服务重点专项(JCZX2023010);高原与盆地暴雨旱涝灾害四川省重点实验室研究型业务重点专项(SCQXKJYJXZD202202);高原与盆地暴雨旱涝灾害四川省重点实验室科技发展基金项目(SCQXKJQN202217);川西南(雅安)暴雨实验室科技发展基金项目(CXNBYSYSMS202407)。

摘　　要：利用地面气象站、LMF1.0三维雷电监测系统、CMPAS多源融合降水、FY-4A卫星云顶亮温等综合观测数据和ERA5再分析资料,对2023年8月20—21日发生在青藏高原东南缘攀西地区的一次突发性山地暴雨的动热力及水汽特征进行诊断分析。结果表明:(1)本次暴雨过程发生在弱天气尺度背景下,500 hPa和700 hPa切变线是主要影响系统,为中尺度对流系统(MCS)发生提供了有利的动力条件,且MCS后向发展较为明显;(2)在中低层高能高湿和强对流不稳定层结条件下,持续的辐合上升运动有利于对流性强降水的发展和维持,局地经向环流的上升支加剧了大暴雨区水汽凝结潜热释放,致使极端短时强降水出现;(3)青藏高原东南缘大地形对云贵高原偏东、偏南气流的阻挡作用造成中低层水汽大量堆积,边界层水汽强辐合,以及中高层较强的垂直水汽通量对局地持续性强降水的发生和维持起到非常关键的作用,强降水区大部分水汽输送集中在边界层至低层,并以云贵高原偏东转偏南路径为主,水汽净收支的演变对降水发展具有一定的指示作用。Using the comprehensive observation data of ground meteorological station,LMF1.0 three-dimensional lighting positioning monitoring,CMA Multisource Precipitation Analysis System(CMPAS)products,cloud-top brightness temperature from FY-4A and ERA5 reanalysis data,a mountainous torrential rain in Panxi region,the southeastern margin of Tibetan Plateau during 20-21 August,2023 was analyzed comprehensively.The following results were obtained:(1)The mountainous torrential rain was effected by the shear lines which provided favorable dynamic conditions for the occurrence of Mesoscale Convective System(MCS)at 500 hPa and 700 hPa under the background of weak synoptic scale,and the backward development of MCS was more obvious.(2)The continuous convergence rising motion was conducive to the development and maintenance of strong convective precipitation under the condition of high energy,high wet and convective instability stratified in the lower and middle layers.The updraft of local meridional circulation aggravated the releasing of latent heat through condensation of water vapor in the torrential rain area,resulting in the occurrence of extreme short-term heavy rainfall.(3)The blocking effect of the large topography of the southeastern margin of the Tibetan Plateau on the easterly and southerly airflow of the Yunnan-Kweichow Plateau caused a large accumulation of water vapor in the lower and middle atmosphere of the Panxi region.The strong water vapor convergence in the boundary layer and the strong vertical water vapor flux in the middle and upper atmosphere played a key role in the occurrence and maintenance of local persistent heavy rainfall.Most of the water vapor transport in the heavy rainfall area was concentrated in the boundary layer to lower atmosphere,which was dominated by the eastward to southward path of the YunnanKweichow Plateau.The evolution of net water vapor budget had a certain indicative effect on the development of precipitation.

关 键 词：山地暴雨 经向环流 凝结潜热 水汽收支 

分 类 号：P458.121.1[天文地球—大气科学及气象学]