浙北地区一次大暴雨过程的等熵位涡分析  

Analysis of isentropic potential vorticity for a heavy rain event in north of Zhejiang

作　　者：周秋林[1] 闵锦忠[2] 梅士龙[1] 

机构地区：[1]嘉兴市气象局,浙江嘉兴314050 [2]南京信息工程大学大气科学学院,南京210044

出　　处：《气象科学》2010年第4期475-480,共6页Journal of the Meteorological Sciences

基　　金：浙江省气象局科技计划项目(2009YB05)

摘　　要：利用NCAR/NCEP逐日再分析资料,对浙北地区2008年6月9—11日大暴雨过程进行等熵位涡分析。结果表明:等熵面上的位涡(IζP)演变反映了暴雨区的移动及西南急流的发展。暴雨区主要位于位涡高值中心的东南侧,对应西南气流发展最强处,而位涡中心降水却不明显。当高位涡中心区南压影响后,强降水结束。通过垂直剖面图可看到,等熵面上的西北急流将高层的高等熵位涡向东向下输送,当浙北地区处于正IζP平流控制下时,强降水发生,当其处于负IζP平流控制时,强降水结束。同时,逆向的Ferrel环流圈的形成,为30°N附近强降水的产生与维持提供了有利的条件。Using the NCAR/NCEP daily reanalysis data,the isentropic potential vorticity（ζIP） analysis of a heavy rain event from 9 June to 11 June,2008 in North of Zhejiang was performed.It is found that the evolution of ζIP reflected the movement of heavy rain areas and development of SW jet.Heavy rain areas were mainly located in the southeastern part of high potential vorticity center,where the strong SW jet appeared.The precipitation in ζIP center was small,and it stopped when the center moved south.Through the vertical profile,it could be seen that the strong NW flow transported the high potential vorticity from high level to eastern low level.When north Zhejiang was under the control of positive ζIP advection,the heavy precipitation occurred.When it was under the negative ζIP advection control,the heavy precipitation stopped.In addition,formation of anti-Ferrel circulation near 30 °N provided favorable conditions for generation and maintenance of rainstorm.

关 键 词：暴雨 等熵位涡 IPV平流 

分 类 号：P458.3[天文地球—大气科学及气象学]