西南季风和热带气旋耦合的暴雨过程诊断分析  

Southwest Monsoon and the Coupled Tropics Cyclone Downpour Process Diagnose Analyse

作　　者：姚胜芳[1] 唐文[1] 何慧 陆丹[1] 

机构地区：[1]广西区气象台,广西南宁530022 [2]广西区气候中心,广西南宁530022

出　　处：《海洋预报》2008年第1期88-94,共7页Marine Forecasts

基　　金：广西区气象台科技攻关项目资助

摘　　要：本文用NCEP/NCAR再分析资料、常规观测资料、FY-2C卫星云图、风廓线资料及自动站资料分析了热带气旋"碧利斯"的路径、陆上维持、暴雨成因。结果表明:"碧利斯"登陆后折向西行与冷空气到达黄淮一带有关,以后折向西偏南行,是受大陆高压南侧东北气流引导;"碧利斯"在陆上维持长、登陆后具有明显的不对称结构,与它处在鞍形场的有利流场、副热带高压从其东面加强西伸、正值西南季风爆发有关;暴雨的发生,与其"处在有利的气候背景,低压环流以罕见的路径从较北的纬度跨越广西"有关;更重要的是西南季风激发西南急流,西南急流输送水汽和释放潜热,利于热带气旋环流的维持,也为暴雨提供充足的水汽条件;急流轴左侧为正切变涡度区,既有利于热带低压环流的维持,又有利于强对流的发生;急流加强风的垂直切变,促使对流风暴不断生成。强降水的发生与西南急流的加强和向下扩展相关,急流指数变化对暴雨短时临近预报有较好预示性。This paper analyses the move path, maintain of the typhoon ＂BILIS＂, reasons of rainstorm. We have used the NCEP/NCAR data, general observational data, FY-2C nephanalysis, wind outline data and automation station data. We obtain some conclusions： ＂BILLS＂ turned to the west after landing. This was connected with cold air between HuangHe River and HuaiHe River area. Then, BILLS turned to the southwest, this was connected with the northeast steering current which located at the south of the high pressure. BILLS lasted a very long time on land and had asymmetric structure after landing. This was connected with saddle current, oceanic high pressure developed from east to west, southwest monsoon breaking out; The rainstorm was connected with the advantaged climate position, low-pressure circumfluence and the infrequence path that BILLS spaned GuangXi from high latitude. Most of all, southwest monsoon aroused the southwest jet stream which transported water vapour and released latent heat, it was good for the continuance of tropics cyclone circumfluence, also it offered enough vapour for the rainstorm. The left of jet stream was the positive vorticity area, it was good for the continuance of the low-pressure circumfluence and the appearance of the strong convection. The jet stream reinforced vertical shear and urged convection storm to develop unceasingly. Strong rainstorm was connected with the strengthen and a down spread of the southwest jet stream. The change of the jet stream index is important for the forecast of short-term rainstorm.

关 键 词：台风暴雨 风廓线 西南季风 急流 

分 类 号：P731[天文地球—海洋科学]