从一次反气旋的生消演变分析陕西初夏连阴雨  

Analysis on Continuous Rainfall in Early Summer of Shaanxi Province Through Evolution of Anticyclone

作　　者：贺皓 刘宇 黄宝霞 

机构地区：[1]陕西省专业气象台,西安710014

出　　处：《气象》2008年第5期58-63,共6页Meteorological Monthly

摘　　要：连阴雨是一种重大天气,特别在"三夏"中出现时。初夏(6月)连阴雨在陕西历史上并不多见,大约3～4年发生一次,且多在关中、陕南出现,陕北黄土高原出现的概率极小。2007年6月。陕西出现了一次长达7天的连阴雨天气。应用NCEP/ NCAR再分析资料,对这次连阴雨天气过程进行了研究,得出:这是一次反气旋环流的生成一维持一消亡过程,陕西位于此反气旋的底部,偏东(南)气流为连阴雨持续提供了良好的水汽;整个过程都有垂直上升运动;稳定持久的蒙古低槽和高原低槽是造成陕西连阴雨的主要天气系统;高原低槽前部的偏南风气流和蒙古冷空气前部的偏北气流在35°N以北河套附近辐合,是形成陕北干旱区连阴雨的主要原因。过程前期,东亚"双阻型"的建立是陕西多雨时段的强信号。As a major weather case, few continuous rainfall process happens in early summer （in June） in history of Shaanxi Province. The probability of continuous rainfall occurrences is much higher in the region of Guanzhong and southern Shaanxi Province about every three or four years than that is in the region of Shanbei Loess Plateau. In June, 2007, an abnormal continuous rainfall process occurred in the whole region of Shaanxi Province, which lasted for seven days. Based on the NCEP/NCAR reanalysis data, this continuous rainfall process was studied. The result showed that this was a process of occurrence, maintaining and disappearance of anticyclone circulation. In this process, Shaanxi Province was at the bottom of this anticyclone, and the east （southeast） wind provided favorable moisture for the continuous rainfall maintaining. Vertical ascending motion happened throughout the whole process. The main synoptic systems were steady an trough and Qinghai-Tibet Plateau trough which caused the continuous rainfall. The south wind in the front of Qinghai-Tibet Plateau trough and north wind in the front of Mongolian trough converged on the Hetao Area, which located in the north of 35°N. That was the main rea- son for the occurrence of the continuous rainfall in Shanbei drought region. Before the process of this continuous rainfall, the establishment of ＂double blocking high＂ in East Asian was the strong signal for the rainy period of Shaanxi Province

关 键 词：连阴雨 环流形势 天气系统 反气旋 

分 类 号：P433[天文地球—大气科学及气象学]