一次高原低涡过程的数值模拟与结构特征分析  

Numerical Simulation and Structure Characteristic Analysis of a Plateau Vortex Process

作　　者：宋雯雯[1,2] 李国平[1,2] 

机构地区：[1]成都信息工程学院大气科学学院/高原大气与环境四川省重点实验室,四川成都610225 [2]中国气象科学研究院灾害天气国家重点实验室,北京100081

出　　处：《高原气象》2011年第2期267-276,共10页Plateau Meteorology

基　　金：国家自然科学基金项目(40875023);灾害天气国家重点实验室开放课题(2009LASW-A01)共同资助

摘　　要：利用非静力中尺度数值模式MM5,模拟了2009年7月29~31日的一次高原低涡过程,结果表明,TBB卫星资料显示出在低涡发展过程中具有同热带气旋类低涡相似的涡眼结构。MM5模式能较好地模拟出低涡的降水落区、强度以及内部结构,正位涡区随着低涡的东移而东移。在动力结构上,低涡发展过程中,涡心处散度和涡度的变化不大,垂直速度由上升运动变为下沉运动。涡眼处涡度的垂直分布与位涡较一致,即涡心位于一个倒Ω型的区域内,两侧各有一个正涡度（正位涡）柱;涡心从低层到高层有辐散下沉运动;在热力结构上,涡区为＂南暖北冷＂结构,涡眼位于相当位温垂直剖面上的相对低值区。Using the nonhydrostatic mesoscale numerical model MM5,a Plateau vortex process occurring during 29~31 July 2009 was simulated and diagnosticly analyzed.The results show that the structure of vortex eye during the vortex development process which displayed by the TBB satellite data is similar to tropical cyclone-like vortices.The MM5 model has enough ability to simulate the precipitation area,precipitation intensity as well as inner structure of vortex,and the positive potential vorticity area move toward east as the vortex move toward east.On the dynamic structure,the vorticity and divergence have little change in the vortex core during the vortex development process,the vertical velocity change ascending into sinking motions.The vertical profile of vorticity in the vortex eye is similar to potential vorticity,that is to say,the vortex core which has a positive vorticity on both sides is in an inverted Ω-type area.The vortex core has divergence sinking motion from lower to upper levels.On the thermal structure,the structure of vortex area is warm in south and cold in north,and the vortex eye is in the lower area on the vertical profile of potential equivalent temperature.

关 键 词：高原低涡 数值模拟 涡眼 位涡 相当位温 

分 类 号：P456.7[天文地球—大气科学及气象学]