东风波诱生低涡发生发展的螺旋度演变特征分析  

Characteristics of Helicity Variation during a Heavy Rainfall Event Caused by Easterly Wave

作　　者：郑峰 

机构地区：[1]浙江省温州市气象局,温州325027

出　　处：《气象科技》2006年第3期275-279,共5页Meteorological Science and Technology

摘　　要：利用NCEP 1°×1°再分析资料对2001年8月3～4日浙南闽北的东风波暴雨过程,根据螺旋度（Helicity）分析了过程中的暴雨演变以及雁荡山脉诱生中尺度低涡发生发展的原因.同时,利用中尺度有限区域模式MM5V2对该东风波诱生中尺度低涡进行模拟.结果表明：螺旋度大值中心强度和位置的演变较好地反映了暴雨落区和中尺度低涡的诱生、移动,螺旋度的时空演变对暴雨发生有一定的预示意义,螺旋度计算较中尺度模式得出诱生低涡初生位置、路径预报准确率高,二者集成可以提高诱生低涡的预报准确率.The heavy rainfall event occurred over the south coast of Zhejiang Province caused by the easterly wave from 3 to 4 August 2001 is studied with the NCEP 1°×1° reanalyzed data by means of helicity analysis and the formation and development causes of the induced mesoscale low vortex over the Yandang Mountains are discussed. Meanwhile, the mesoscale area-limited model MM5V2 is used to simulate the mesoscale low vortex induced by the easterly wave. The results indicate that there exits close relationship between helicity and heavy rainfall, and the high helicity is one of mechanisms for heavy rainfall development. The combination of helicity and MM5 model in practice can improve low vortex forecast and heavy rainfall forecast.

关 键 词：东风波 中尺度低涡 螺旋度 MM5模拟 

分 类 号：P315.72[天文地球—地震学] S763.310.6[天文地球—固体地球物理学]