重旱背景下山西春季一次异常暴雨过程分析  

Analysis of a heavy rain event shifted from long drought in Shanxi Province in the spring

作　　者：赵海英[1] 赵建峰[1] 

机构地区：[1]山西省气象台,山西太原030006

出　　处：《山西气象》2012年第4期12-15,共4页Shanxi Meteorological Quarterly

摘　　要：本文利用高空、地面观测资料及物理量场，对山西春季一次重旱背景下的异常暴雨过程进行了分析。结果表明，高空南北两支低值系统相互作用是这次过程的预报着眼点，两支低值系统在山西发生同位相叠加，其前方的西南气流合并加强，导致对流层中低层西南急流加强，上升运动加剧，为暴雨的发生提供了必要的环流条件。海平面气压场的分析表明，地面东西路冷空气的交替影响也是山西出现持续性降水的原因。物理量场的分析表明，降水落区与水汽通量、水汽通量散度、θse的大值区有较好的对应关系。High atmosphere and surface observational data and physical field is used, and a abnormal heavy rain event in severedrought background in Shanxi Province in the spring of 2011 is analyzed in this paper. The results show that the interaction of the north low-pressure system and the south low-pressure system is the focus of the forecast of this heavy rain event. The in-phase superposition of the two low systems is occurred in Shanxi Province. The south-west flows in front of the two low systems are merged and strengthened, which result in the enhance of south-west jet in the middle and lower troposphere and the intensify of ascending motiion, The analysis of sea surface pressure indicated that the impact alternately of the cold air from west and the cold air from east is another cause of the continued rainfall. The analysis of physical field show that the distribution of the rainfall is basically correspond to the large value centers of vapor flux,divergence of vapor flux and pseudo-equivalent potential temperature.

关 键 词：重旱背景 异常暴雨 南北支系统 东西路冷空气 相互作用 

分 类 号：P458.121.1[天文地球—大气科学及气象学]