Topographic effects on polar low and tropical cyclone development in simple theoretical model  

作　　者：李子良 傅刚 郭敬天 端义宏 张美根 

机构地区：[1]Department of Marine Meteorology,Ocean University of China [2]Shanghai Typhoon Institute [3]State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, State Oceanic Administration [4]State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry,Institute of Atmospheric Physics, Chinese Academy of Sciences [5]North China Sea Marine Forecasting Center of State Oceanic Administration [6]National Meteorological Center, China Meteorological Administration

出　　处：《Applied Mathematics and Mechanics(English Edition)》2009年第10期1271-1282,共12页应用数学和力学（英文版）

基　　金：supported by the National Natural Science Foundation of China (Nos. 40775069 and 40675060);the Science Foundation of Shanghai Typhoon Institute (No. 2006STB03);the Science Foundation of State Key Laboratory of Satellite Ocean Environment Dynamics (No. SOED0904);the Ministry of Science and Technology of the People’s Republic of China (Nos. 2009CB421504 and 2006AA09Z151);the China Meteorological Administration (No. GYHY200706031);the State Oceanic Administration (No. 908020310)

摘　　要：The polar low and tropical cyclone type vortices over topography are assumed to be the axisymmetrical and thermal-wind balanced systems, which are solved as an initial value problem of a linearized vortex equation set in cylindrical coordinates. The roles of the sensible and latent heating, friction, and topography in the structure and intensification of the polar low and tropical cyclone type vortices are analyzed. The radial velocity, vertical velocity, azimuthal velocity, and the unstable growth rate including the topography effects are obtained. It is shown that the interaction between the flow and the topography plays a significant role in the structure and intensification of the polar low and tropical cyclone system. The analysis of the topography term indicates that, in the up-slope side of the mountain, the radial inflow and the vertical ascent forced by the mountain can intensify the polar low and tropical cyclone type vortex and increase the unstable growth rate. However, in the lee side of the mountain, the radial inflow and the vertical descent forced by the mountain can weaken the polar low and tropical cyclone type vortex and decrease the unstable growth rate of the polar low and tropical cyclone system. In addition, the evolutionary process and the spatial structure of the polar low observed over the Japan Sea on 19 December 2003 are investigated with the observational data to verify this theoretical result.The polar low and tropical cyclone type vortices over topography are assumed to be the axisymmetrical and thermal-wind balanced systems, which are solved as an initial value problem of a linearized vortex equation set in cylindrical coordinates. The roles of the sensible and latent heating, friction, and topography in the structure and intensification of the polar low and tropical cyclone type vortices are analyzed. The radial velocity, vertical velocity, azimuthal velocity, and the unstable growth rate including the topography effects are obtained. It is shown that the interaction between the flow and the topography plays a significant role in the structure and intensification of the polar low and tropical cyclone system. The analysis of the topography term indicates that, in the up-slope side of the mountain, the radial inflow and the vertical ascent forced by the mountain can intensify the polar low and tropical cyclone type vortex and increase the unstable growth rate. However, in the lee side of the mountain, the radial inflow and the vertical descent forced by the mountain can weaken the polar low and tropical cyclone type vortex and decrease the unstable growth rate of the polar low and tropical cyclone system. In addition, the evolutionary process and the spatial structure of the polar low observed over the Japan Sea on 19 December 2003 are investigated with the observational data to verify this theoretical result.

关 键 词：TOPOGRAPHY analytical solutions polar low tropical cyclone 

分 类 号：P444[天文地球—大气科学及气象学]