A SEMI-CIRCLE THEOREM FOR UNSTABLE PERTURBATION IN TROPICAL CYCLONE-SCALE VORTICLES  

作　　者：HUANG Hong ZHANG Ming XU Ming 

机构地区：[1]Institute of Meteorology, PLA University of Science and Technology, Nanjing 211101, China [2]Shanghai Typhoon Institute, China Meteorological Administration, Shanghai 200030, China [3]Laboratory of Typhoon Forecast Technique/CMA, Shanghai 200030, China

出　　处：《Journal of Hydrodynamics》2009年第4期473-481,共9页水动力学研究与进展B辑（英文版）

基　　金：supported by the National Nature Science Foundation of China (Grant No.40575023);supported by the China Meteorological Administration Shanghai Typhoon Institute Typhoon Research Fund (Grant No. 2008ST06)

摘　　要：In this paper, we discusses the spectrum distribution of baroclinic disturbances in tropical cyclone-scale vortices with the assumption that the basic flow does not vary with height. The semi-circle theorem for the unstable perturbation is obtained and the upper bound of growth rate can be estimated. The upper bound of instability growth rate increases with the increase of the maximum basic-state tangential wind speed, angular speed, inertial parameter, absolute vorticity, radial gradient of absolute vorticity and static stability. The upper bound of instability growth rate is greater for vortices of larger horizontal scale and smaller vertical scale and lower wave-number disturbances.In this paper, we discusses the spectrum distribution of baroclinic disturbances in tropical cyclone-scale vortices with the assumption that the basic flow does not vary with height. The semi-circle theorem for the unstable perturbation is obtained and the upper bound of growth rate can be estimated. The upper bound of instability growth rate increases with the increase of the maximum basic-state tangential wind speed, angular speed, inertial parameter, absolute vorticity, radial gradient of absolute vorticity and static stability. The upper bound of instability growth rate is greater for vortices of larger horizontal scale and smaller vertical scale and lower wave-number disturbances.

关 键 词：tropical cyclone-scale vortex spiral bands instability semi-circle theorem 

分 类 号：O151.21[理学—数学] P444[理学—基础数学]