山地中尺度环流中的大气边界层湍流摩擦效应  

THE ROLE OF SURFACE FRICTION IN MOUNTAININDUCED MESOSCALE ATMOSPHERIC CIRCULATION

作　　者：陈明[1] 傅抱璞[1] 郑维忠[1] 

机构地区：[1]南京大学大气科学系

出　　处：《气象学报》1996年第2期216-224,共9页Acta Meteorologica Sinica

基　　金：国家自然科学基金

摘　　要：建立了一个三维原始方程数值模式，模拟在光滑下边界和无滑脱下边界两种情况下，山区中尺度环流的演变过程，指出在弱层结条件下，边界层湍流摩擦效应有利于流场的分离和涡旋偶极子环流的发展；在强层结条件下，表面摩擦效应削弱了分离气流和涡旋性环流的强度，但使其范围扩大。边界层湍流摩擦效应引起的分离流场和尾流区环流与非粘性动力过程引起的流场分离现象，虽然从其表现形式上看完全相同，但是其形成则是由完全不同的物理机制所控制。边界层湍流摩擦效应在上述两种分离流场的演变过程中表现出完全相反的作用。地转科氏力的调整作用在山地背风坡上促进了气旋性辐合环流的发展，而抑制了反气旋性环流的发展。n this article we set up a three-dimensional numerical model to simulate mountaininduced mesoscale atmospheric circulation and discuss the role of surface friction in the evolution of this circulation.The results show that under condition of weak baroclinicity,the surface frictional effects promote separation and are favorable of the formation of depole of lee vortices,but under strong baroclinicity condition the surface frictional effect depresses the separation and weakens the strength of lee vortices.However,the extention of lee vortices and returned flow are enlarged.Though the lee vortices are unique in their method,they are controled by different mechanics.One is caused by surface frictional effect.the other is caused by non-frictional dynamical effect. The role of surface friction is contrary in these two mechanics.

关 键 词：中尺度 大气环流 湍流 摩擦效应 大气 边界层 

分 类 号：P434[天文地球—大气科学及气象学] P425.2