大尺度环境场对热带气旋影响的动力分析

DYNAMICAL STUDIES ON THE EFFECT OF LARGE-SCALE ENVIRONMENTAL FLOW ON TROPICAL CYCLONES

摘要: 文中基于正压大气运动的基本方程组,把大气运动场分解为大尺度环境场和热带气旋环流,采用动力分析的方法,分析了有/无大尺度环境场作用的热带气旋运动特征.结果表明:无环境场时,热带气旋的运动遵循位涡守恒原理、热带气旋的定常运动满足相当地转风平衡关系(f平面近似),其等位涡线和等压能线均与流线重合;有环境场时,热带气旋的运动不再遵循位涡守恒原理、其定常运动的等位涡线和等压能线也均与流线不再重合,但热带气旋的定常运动满足准相当地转风平衡关系(f平面近似)、等相当压能线与流线重合.最后还能过建立有/无大尺度环境场作用的热带气旋强度变化及移动速度的方程式,定性地分析了大尺度环境场对热带气旋强度变化及移动的影响.

Abstract: Based on the barotropic model,in this paper,the atmospheric motion field can be decomposed into the tropical cyclone (TC) field and large-scale environment flow (LSEF),and the dynamical charact eristics of TC with or without LSEF were analyzed.Finally,the movement and intensity change equations of TC with or without LSEF were built,and the effects of LSEF on the movement and intensity change of TC were discussed.