变形场锋生条件下斜压锋区上对称波包的发展

文中用 WKBJ方法讨论了叠加在 Hoskins- Bretherton( 1 972 )变形场锋生模型背景上对称斜压波包的发展问题。在锋区斜压气流对称稳定的条件下 ( F2 N2 - M2 =q>0 ) ,大尺度变形场强迫、锋生环流的作用及锋生过程引起的稳定度参数 ( F2 ,N2 ,M2 )的个别变化也会对对称扰动的发展产生作用 ,变形场锋生和锋区环流的上升支下方有利于对称扰动发展 ,而锋区附近非地转垂直切变和稳定度参数的变化对扰动的影响则与对称扰动的结构有关。

THE DEVELOPMENT OF SYMMETRIC DISTURBA-NCES SUPERPOSED ON BAROCLINIC FRONTAL ZONE UNDER THE ACTION OF DEFORMATION FIELD

The development of symmetric disturbances superposed on the background field of Hoskins Bretherton(1972)frontogenesis model is investigated by using the WKBJ approach.It is found that the forcing of large scale deformation,the frontal circulation and the variations of stability parameters( F 2,N 2,M 2 )can induce the development of symmetric disturbances even though the frontal baroclinic flow is symmetric stable( F 2N 2-M 2=q>0 ).The frontogenetical process of deformation confluence and the ascending branch of frontal circulation are in favor of the development of symmetric distur bance.The actions of ageostrophic shear in frontal zone and the variation of stability parameters are dependent on the structure of disturbances.