一次强对流天气及其中短时强降水的成因分析  

Cause analysis on a severe convective weather and accompanied short-term heavy rainfall

作　　者：阿不都外力.阿不力克木 王元[1] 王亦平[1] 费启瓅 

机构地区：[1]南京大学大气科学学院中尺度灾害性天气教育部重点实验室,南京210093 [2]江苏省气象局,南京210008

出　　处：《气象科学》2014年第4期457-464,共8页Journal of the Meteorological Sciences

基　　金：公益性行业(气象科研)专项(GYHY200906011);国家重点基础研究发展计划(973计划)项目(2013CB430100);国家自然科学基金资助项目(41172199)

摘　　要：利用常规地面、高空观测资料,自动站资料,NCEP再分析资料,多普勒雷达资料和WRF模式模拟资料等,对2009年6月初晋豫鲁皖苏5省的一次强对流天气及其中短时强降水的形成原因进行了分析。结果表明:本次过程是在高空东北冷涡不断引导冷空气南下,与低层低涡扰动形成冷暖空气汇合的有利天气形势下发生的。边界层内的强烈辐合抬升是触发对流发生和释放对流不稳定能量的主要原因之一。高空有明显的干侵入并叠加在低层高假相当位温的暖湿空气之上,这种较强的位势不稳定形势对本次过程中对流系统的触发提供了有利的条件。对流系统移动方向一侧有较强的风暴相对螺旋度,通过低层辐合上升气流的倾斜作用,使更多的水平涡度转化为垂直涡度,为本次过程的发展、维持以及其短时强降水的发生提供了有利的条件。Based on conventional surface data,upper-air observation,automatic station,NCEP reanalysis,Doppler radar and WRF model simulation data,the characteristics and causes of a severe convective weather process with short-term rainstorm in Shanxi,He＇nan,Shandong,Anhui and Jiangsu provinces in the early June,2009 were analyzed.Results show that the severe convective weather occurred under favorable condition of cold and warm air confluence formed by the convergence of the southerly cold air guided by northeast cold vortex at high level with the low vortex disturbance at low level.The strong convergent updraft in boundary layer was one of the main reasons for triggerring the convection and releasing the convective instability energy.Furthermore,the strong potential instability caused by the over-lapping of dry intrusion at upper level upon the wet and warm air of the high Potential Vorticity （PV） at lower level provided a favorable condition for the development of the severe convective weather.Moreover,a strong storm relative helicity existed on the side of the movement direction of the convective system,and the tilting effects of updraft air in the low convergence made the horizontal vorticity transform into the vertical one,which all provided a favorable condition for the development and maintaining of this severe convective weather and accompanied short-term rainstorm.

关 键 词：强对流天气 短时强降水 干侵入 风暴相对螺旋度 

分 类 号：P458.121.1[天文地球—大气科学及气象学]