一次典型西南涡降水的垂直结构和微物理特征研究  

Vertical Structure and Microphysical Characteristics of Clouds and Precipitation Induced by a Typical Southwest Vortex

作　　者：江叶 刘艳霞[1] 文军[1] 郑佳锋[1] 陈杨瑞雪 JIANG Ye;LIU Yanxia;WEN Jun;ZHENG Jiafeng;CHENYANG Ruixue(College of Atmospheric Sciences,Chengdu University of Information Technology,Chengdu 610225,China)

机构地区：[1]成都信息工程大学大气科学学院,四川成都610225

出　　处：《成都信息工程大学学报》2024年第6期718-726,共9页Journal of Chengdu University of Information Technology

基　　金：国家自然科学基金资助项目(42205008)。

摘　　要：为进一步认识西南涡降水的影响,利用2020年8月11日全球降水测量卫星(GPM)星载双频雷达(DPR)探测资料,结合欧洲中期天气预报中心ERA5再分析资料、地面自动站资料和FY-2G卫星资料,对一次典型西南涡降水的垂直结构和微物理特征进行研究。结果表明:此次过程由高原涡诱生出西南涡导致,盆地西部整体位于槽前正涡度区域,受偏南暖湿气流的控制。此次西南涡降水表现为混合性降水,即片状的层云降水中混入块状的对流降水。雷达测量的雨顶高度与降水的大值区相对应,反应出上升对流强烈。雷达的观测结果表明,两类降水的垂直结构和微物理过程有显著差异。对于层云降水,其垂直尺度较大,其回波强度、数浓度、粒径及降水强度整体随高度下降而增大,雨滴谱分布更集中,以浓度略低的中小雨滴为主。冻结层以上,凝华、碰并等效率较低且缓慢;冻结层以下,以碰并过程为主。而对流降水的垂直尺度更大,粒径大且浓度高,导致回波强度和降水强度较大,以浓度较高的中大雨滴为主。冻结层以上,有快速的冰晶增长及活跃的冰相过程;冻结层以下,以碰并和破碎为主,效率强于层云降水。To further understand the influence of southwest vortex precipitation,the Global Precipitation Measurement Satellite(GPM)spaceborne dual-frequency radar(DPR)detection data from August 11,2020,combined with the EC-MWF ERA5 reanalysis data,ground automatic station data,and FY-2G satellite data,The vertical structure and micro-physical characteristics of typical southwest vortex precipitation are studied.This process is caused by the southwest vor-tex induced by the plateau vortex,and the western part of the basin is located in the positive vorticity area in front of the trough,which is controlled by the southerly warm and wet air.The Southwest Vortex precipitation showed mixed precipi-tation,that is,flaky stratus precipitation mixed with massive convective precipitation.The height of the rain-top meas-ured by the radar corresponds to the large value area of the precipitation,which reflects the strong upward convection.The radar observation results show that the vertical structure and microphysical processes of the two types of precipitation are significantly different.For stratiform precipitation,the vertical scale is large,and its echo intensity,raindrop con-centration,diameters,and precipitation intensity increase with the decrease in height.The raindrop spectrum distribu-tion is more concentrated,mainly small and medium-sized raindrops with slightly lower concentration.Above the freez-ing layer,the efficiency of condensation and collision-coalescence is low and slow.Below the freezing layer,the colli-sion-coalescence is the main process.For convective precipitation,the vertical scale,raindrop diameters and concentra-tion are larger,leading to larger echo intensity and precipitation intensity,mainly large raindrops with higher concentra-tion.Above the frozen layer,there is rapid ice crystal growth and an active ice phase process.Below the frozen layer,collision-coalescence and shattering are the main,and the efficiency is stronger than stratiform precipitation.

关 键 词：西南涡 GPM卫星 垂直结构 微物理特征 

分 类 号：P412.27[天文地球—大气科学及气象学]