低空急流演变对阜新地区短时暴雨影响研究.doc

低空急流演变对阜新地区短时暴雨影响研究
摘要:利用阜新地区2004-2013年29次天气过程中36个时次短时暴雨相关数据,采用统计学、天气学和物理量计算等方法,从低空急流的角度对阜新地区短时暴雨的时间分布规律、天气形势、典型环境场特征和预报指标进行研究,并利用2013年8月12日午后发生的短时暴雨天气过程对低空急流的作用进行了探讨。结果表明:(1)阜新地区短时暴雨的月变化特征显著,主要发生在6~8月;日变化规律也非常明显,11:00~18:00时出现的几率最大。(2)阜新地区产生短时暴雨的天气系统按照低空急流和500hPa天气形势分为涡旋式急流型、高空槽前急流型、副高西北部急流型、横槽式无急流型等4种类型;(3)低空急流的气流多来自热带洋面上,因此它往往起着输送低空大量的热量、水汽和动量的作用,当它将暖湿空气输送到较干较冷空气的下方时,就形成了不稳定层结,在低空急流左侧上升运动的触发下,易产生对流性降水;(4)选取中低层比湿、露点、涡度、散度、垂直速度、K指数、θse(850-500)、T(850-500)、V(700-850)、V(850-925)等物理量作为预报因子,建立本地化短时暴雨预报指标。
关键词:低空急流;短时暴雨;影响研究;阜新地区
中图分类号 P458 文献标识码 A 文章编号 1007-7731(2014)15-146-06
Abstract:Temporal distribution, physical quantity field and prediction index of 29 weather processes of short-time rainstorm in 36-times from 2004 to 2013 in Fuxin the use
of the methods of statistics, synoptic meteorology and physical quantity calculation. And the effecting of low-level jet was explored based on the short-time heavy rain at pm on August 12,2013. The results showed that,(1)The time-space distribution of short-time rainstorms was not uniform. Its monthly variation was significant, focusing primarily on June to August, diurnal change was great, mostly appearing from 11:00 to 18:00.(2)According to low-level jet and weather situation of 500hPa, rainstorm weather can be divided into four types: vortex-jet, front of upper groove-jet northwestern of the subtropical high-jet, sidelong gro