低纬高原两次冷锋切变天气对比分析  

A Comparison Between Two Cold Front Shear Processes over Lower Latitude Plateau of China

作　　者：金少华 葛晓芳 艾永智 李桂华 

机构地区：[1]云南省玉溪市气象局,玉溪653100

出　　处：《气象》2010年第6期35-42,共8页Meteorological Monthly

摘　　要：应用NCEP再分析资料、FY-2卫星TBB资料、加密雨量站等资料,对2008年7月2日、5日两次影响滇中的冷锋切变天气进行对比分析。结果表明:冷锋切变系统的强弱、移速对降雨强度影响较大,切变线上中尺度系统的生成和维持时间对降雨强度作用非常明显。在冷锋切变系统影响滇中过程中,滇缅高压脊对水汽输送和水汽辐合有重要作用。两次降水强度上出现的差异主要是由于两次过程中对流发展强弱不同引起,假相当位温、K指数、总能量、对流有效位能等热力不稳定指数能很好地反映出对流发展过程中强弱变化的差异。不同环境场的作用导致物理量场发生不同改变,是冷锋切变系统中降水出现强弱变化的主要原因。Based on the NCEP reanalysis,FY-2 satellite TBB and rainfall data from automatic precipitation stations etc.,the two cold front shear processes which occurred in Yunnan on July 2 and 5,2008 were analyzed. The results show that the cold front shear,range and rainfall between two processes are distinctly different,and that the intensity and movement of cold front sheer affect the intensity of rainfall.Meanwhile, the generation and maintaining of mesoscale system originated in sheer line significantly influence the intensity of rainfall.The Yunnan-Burma high ridge,plays an important role in vapor transport and convergence.The rainfall intensity differences result in the differences of strength of convection development during two convection processes,and thermal instablility indexes such as pseudo-equivalent potential temperature,K index,total energy,CAPE,etc.Could reflect the differences of development of convection. Different conditions lead to different changes of physical fields,which is the main reason for intensity changes of precipitation occurring in cold front sheer system.

关 键 词：冷锋切变 Β中尺度 对比分析 低纬高原 

分 类 号：P457.6[天文地球—大气科学及气象学]