2008年7月黄淮暴雨过程中西南涡结构特征分析  

The analysis on the structure characteristics of the Southwest Vortex in a rainstorm event in July 2008 over Huanghuai valley

作　　者：王新敏[1,2] 张霞 孙景兰[3] 吕林宜 徐文明 

机构地区：[1]中国气象局农业气象保障与应用技术重点开放实验室,郑州450003 [2]河南省气象台,郑州450003 [3]河南省气象局,郑州450003

出　　处：《暴雨灾害》2015年第1期54-63,共10页Torrential Rain and Disasters

基　　金：中国气象局2014年气象关键技术集成项目(CMAGJ2014M31);中国气象科学研究院灾害天气国家重点实验室开放基金项目(201205);中国气象局成都高原气象研究所高原气象开放实验室基金课题(LPM2012014)

摘　　要：对西南涡暴雨的预报不仅取决于对西南涡移动路径的把握,也与西南涡的结构及其演变密切相关。利用NCEP/NCAR 1°×1°逐6 h再分析资料,对2008年7月一次东移影响黄淮的西南涡的结构特征和暴雨机理进行分析,结果表明:西南涡的生成过程包含高原涡的耦合诱发,西南涡的生成、发展与干位涡向对流层低层扰动下传有关;中高纬冷空气与副热带高压边缘暖湿气流对峙加强了系统的斜压性,使西南涡中心向上伸展的位涡柱和正涡度柱具有向西倾斜的结构;成熟的西南涡具有中尺度非对称的显著斜压结构特征;对流层中层正涡度平流是西南涡发展和引导西南涡移动的重要因素;凝结释放大量潜热促使低层西南低涡发展,使降水增强。The forecast of heavy rain induced by vortex is not only determined by the vortex movement track, but also closely related to its structure and revolution. Based on NCEP/NCAR 1°×1° 6-hourly reanalysis data, the structure characteristics of southwest vortex and the mechanism of heavy rain production in July 2008 are analyzed. The results show that the formation process of southwest vortex includes the coupling and induction of Tibetan Plateau vortex, and the generation and development of southwest vortex are related to the transport of dry potential vorticity downwards to the lower troposphere. The confrontation of cold air from middle-high latitudes and warm-wet air along the edge of the sub-tropic high strengthens the baroclinicity of the system, which makes the potential vorticity column and positive vorticity col- umn over the vortex center incline westward with height. The mature southwest vortex is with a meso-scale asymmetric significantly baro- clinic structure. The positive vorticity advection in the mid-troposhere is an important factor that makes southwest vortex develop and move. The latent heating makes southwest vortex develop, thus enhances the precipitation.

关 键 词：西南涡 动力结构 暴雨 位涡 凝结潜热 

分 类 号：P458[天文地球—大气科学及气象学]