摘要
利用NCEP资料、MICAPS资料、常规观测资料,对2013年3月13日晚在广西出现的混合型强对流天气过程分析后显示,此次强对流天气出现在500 hPa的冷空气先行侵入,形成上干下湿的强烈位势不稳定状态下,200 hPa急流入口右侧的辐散气流,加强了上升运动,弥补了缺少高空槽前抬升机制的不足。地面锋面在广西境内摆动,白天气温偏高,不稳定能量得到积聚,随着切变线及辐合线南压,触发不稳定能量释放。对流层中层风速及风向的强垂直切变与低层正值螺旋度相配置,是产生大风的动力条件。对流层中层的强势正涡度在下传过程中,使地面气旋性辐合加强,形成旋转大风,将南海湿润充足的暖湿空气卷入吴圩附近,冷空气从西北面楔入,抬升暖湿气流,对流发展,在辐合线以南约50 km处形成短时强降水。强的风垂直切变环境中,动力效应加强了上升气流的强度,使得冰雹得以在较小至中等强度的CAPE中发展。
Based on NCEP reanalysis data,MICAPS data and routine observation data,the mixing strong con-vection weather happed in Guangxi in the evening of March 13,2013,is analyzed.The dry wet strong potential in-stability station is caused by the invasion of cold air on the 500hpa,and the strong upward motion which become se-verer under the scattered radiation flow in the right side of the entrance of the 200hpa jet,by which the inadequate lifting mechanisms of high-altitude slot is made up,are triggering conditions of the severe convection weather. Ground frontal is swing in Guangxi while the unstable energy is accumulated under the high temperature in daytime, because of which unstable energy is released when the shear line and the convergence line moving to the south of Guangxi.The configuration of vertical high speed wind in the middle troposphere and the positive helicity in the lower layer is the dynamic condition of the strong wind.The ground cyclonic convergence is strengthening as the strong positive vorticity is passing down,forming the strong Rotating wind,by which the moist and warm air upon the south sea is involving into Wuxi,while a short-time heavy rainfall is happened in the area of 50 meters around the south convergence line.Hail is developing in the moderate intensity station of CAPE generated by the strong vertical wind shear environment,and the dynamic effect of this shear environment makes the updrafts stronger.
出处
《灾害学》
CSCD
北大核心
2014年第4期38-42,共5页
Journal of Catastrophology
基金
广西科技厅项目(桂科攻0993002-1)
广西气象局重点科研项目(桂气科201302)
关键词
混合型
强对流天气
冰雹
短时强降水
春季
广西
mixing
severe convection weather
hail
short-time heavy rainfall
spring
Guangxi
