鲁南一次暖区大暴雨触发与维持机制分析  

The Trigger and Maintenance Mechanism of a Warm-Sector Heavy Rainfall in Southern Shandong

作　　者：黄燕玲 王亚兰 袁月 HUANG Yanling;WANG Yalan;YUAN Yue(Key Laboratory for Meteorological Disaster Prevention and Mitigation of Shandong,Jinan 250031,China;Zaozhuang Meteorological Bureau,Zaozhuang 277800,China;Lishui Meteorological Bureau,Lishui 323000,China;Jining Meteorological Bureau,Jining 272004,China)

机构地区：[1]山东省气象防灾减灾重点实验室,山东济南250031 [2]枣庄市气象局,山东枣庄277800 [3]丽水市气象局,浙江丽水323000 [4]济宁市气象局,山东济宁272004

出　　处：《沙漠与绿洲气象》2024年第4期43-50,共8页Desert and Oasis Meteorology

基　　金：中国气象局预报员专项(CMAYBY2020-073);山东省气象局预报员专项(SDYBY2020-09、SDYBY2019-09)。

摘　　要：利用区域自动站资料、ERA5再分析资料、FY-2F云顶亮温资料、多普勒雷达等资料对2019年8月5—6日鲁南大暴雨过程的环流背景、环境场条件、中尺度对流系统(MCS)演变特征及其触发机制进行分析。结果表明:(1)暴雨过程发生在副热带高压边缘的弱天气强迫背景下,大尺度环流形势配置不是很有利;(2)深厚的湿层、较低的抬升凝结高度(LCL)和自由对流高度(LFC)、上干下湿的不稳定层结为大暴雨的产生提供了有利的环境条件;(3)暖区强降水发生在鲁中山脉向苏北平原的过渡带上,呈狭长带状,5日午后和夜间先后生成的准静止β中尺度对流系统(MβCS)共同导致大暴雨过程的发生,小时强降水中心主要出现在MβCS云团TBB梯度大值区附近;(4)5日午后鲁南和6日凌晨枣庄中部强降水的触发机制为地面中尺度辐合线,MCS沿着辐合线不断新生和发展,形成“列车效应”,造成大暴雨。6日凌晨临沂西北部强降水由850 hPa露点锋触发,鲁中山脉峡谷风效应和迎风坡的动力抬升作用促使MCS增强发展;(5)强降水的持续与850 hPa露点锋、冷池和边界层暖湿气流增强引起的地面辐合线的长时间维持有关。Based on data from regional automatic stations,ERA5 reanalysis,FY-2F cloud-top brightness temperature,and Doppler weather radar,this study conducted an extensive analysis of the circulation background,environmental conditions,mesoscale convective system(MCS)evolution characteristics,and trigger mechanism of heavy rainfall in southern Shandong province on August 5-6,2019.The key findings are summarized as follows:(1)The rainstorm process transpired under weak weather background forcing,occurring at the periphery of the subtropical high,and was characterized by unfavorable large-scale circulation patterns.(2)Favorable environmental conditions conducive to heavy rain development included a substantial and moisture-laden atmospheric layer,lower uplift condensation height(LCL),free convection height(LFC)and unstable stratification featuring upper dry layers and lower moist layers.(3)The heavy rainfall was concentrated in the warm sector transition zone spanning from the mountainous region of Mid-Shandong to the North Jiangsu Plain,presenting as a narrow,elongated band.Successive occurrences of quasi-steady MesoscaleβConvective Systems(MβCS)during the afternoon and night of August 5 were primarily responsible for the heavy precipitation centers,which predominantly clustered near the areas exhibiting maximum Top Brightness Temperature(TBB)gradients within the MβCS cloud system.(4)The trigger mechanisms for heavy precipitation in southern Shandong on the afternoon of August 5 and in Zaozhuang on the morning of August 6 were attributed to the surface mesoscale convergence line.Along this line,the MCS continuously emerged and underwent progressive development,displaying a"train effect"and consequently leading to heavy rainfall occurrences.Additionally,the heavy precipitation observed in the northwest of Linyi was initiated by the 850 hPa dew point front in the early hours of the 6th.The canyon wind effect and dynamic uplift on the windward slope within the mountainous region of Mid-Shandong significantly contributed to

关 键 词：暖区大暴雨 中尺度对流系统 地面辐合线 地形作用 

分 类 号：P458.3[天文地球—大气科学及气象学]