梅雨暴雨期重力惯性波的发展与雨带的活动  

Relationship Between the Development of Inertia-gravity Wave and the Movement of Rain-band During Meiyu and Storm Rainfall Period

作　　者：常越[1] 何金海[2] 丁治英[2] 杨帅[2] 

机构地区：[1]广州市气象局,广州510080 [2]南京信息工程大学,南京210044

出　　处：《应用气象学报》2006年第3期296-302,共7页Journal of Applied Meteorological Science

基　　金：国家基础研究发展规划项目(2004CB418303)资助

摘　　要：由1991年7月5—6日一次梅雨期暴雨过程的中尺度扰动场分析,发现高低层重力惯性波的发展与传播和雨带、低涡的发展与传播有密切的联系,高低层重力惯性波有明显不同的传播形式。结果表明:降水初期,对流不稳定激发出重力惯性波,低层南部相对稳定,有向南传播的重力惯性波,高层出现传播的重力惯性波,高低层向南传播的重力惯性波有利于多条雨带的形成;降水中期,高层的重力惯性波出现围绕低层涡旋中心逆时针旋转,降水也开始加大并东移;高层向北传播的重力惯性波可导致低层的涡旋和降水发展。Storm rainfall in Meiyu season in 1991 causes great damages to mid-lower reaches of the Yangtze River, and many researchers have done a lot of studies on it. But there are only a few researches on the relationship between the movement of Meiyu rain-band and inertia-gravity wave. NCEP/NCAR reanalysis data and MM5 non- hydrostatic model are used to simulate the precipitation procedure during the period of 00：00 （UTC）, July 5, 1991 to 12：00, July 6,1991, and the result is diagnosed to reveal the inner relationship between the propagation of inertia-gravity wave and the movement of rain-band in this process. The analysis on the meso-scale perturbation field of the storm rainfall in the Meiyu season indicates that the development and propagation of inertia-gravity wave is closely related to the development and propagation of rain-band, and the propagation form of upper inertia-gravity wave is different from the lower one. At the early stage of the rainfall, positive and negative vorticity band lies from east to west in the upper and lower layer of mid latitudes. The positive and negative vorticity in the southern part of rainfall area distributes alternately from northeast to southwest. Typical inertia-gravity character and southward-propagation tendency is also revealed in divergence diagram. The upper inertia-gravity wave propagates southwards later than the lower one, and vorticity and divergence bands distribute like the shape of ＂8＂. North-east vorticity and divergence bands propagate southwards, but south-west ones propagate northwards. In the mid-period of precipitation, upper inertia-gravity wave shows the tendency of counter clock-wise rotation around the lower vortex center, at this time, rainfall begins to increase and moves eastwards. Inertia-gravity wave has the character of distributing in the out-of-phase form. The lower layer does not shows the rotation around vortex feature similar to the upper layer. The allocation of upper and lower layers provides beneficial dynamical condition to th

关 键 词：重力惯性波 梅雨暴雨 雨带 对称不稳定 

分 类 号：P426.62[天文地球—大气科学及气象学]