阵风锋、海风锋和冷锋等触发局地强对流风暴实例分析  

Case study on severe local convective storms triggered by gust fronts,sea breeze fronts,and cold fronts

作　　者：刁秀广[1] DIAO Xiuguang(Shandong Meteorological Observatory,Jinan 250031,China)

机构地区：[1]山东省气象台,山东济南250031

出　　处：《海洋气象学报》2018年第4期45-57,共13页Journal of Marine Meteorology

基　　金：山东省自然科学基金项目(ZR2016DM20);环渤海区域科技协同创新基金项目(QYXM201614);山东省气象局科研项目(2012sdqxz05;2016sdqxz01)

摘　　要：利用CINRAD/SA雷达探测资料,结合地面实况和探空资料,对7次典型中尺度辐合线触发强对流风暴的特征进行了分析。结果表明:阵风锋、海风锋和冷锋等边界层辐合线在一定条件下雷达低层反射率因子产品上表现为清晰的窄带回波,某些辐合线在反射率因子产品上不能得到任何有用信息,但在低层径向速度上可识别出线性径向速度辐合;识别出窄带回波或清晰的径向辐合线约1 h后,是雷暴首次触发的主要时间段;对于干型强对流风暴产生的阵风锋,其右侧往往是雷暴触发的主要区域,导致风暴右向传播;湿型强对流风暴产生的阵风锋,激发雷暴的方向与雷暴平均移动方向基本相反,导致风暴呈后向传播特征;海风锋向内陆推进速度快的区域是雷暴触发的主要区域,后继雷暴具有两侧传播特征;单纯的线性低层径向速度辐合在合适的环境条件下触发强对流,主要特征是对流风暴移动缓慢,可造成局地灾害性强降雨天气。Based on the observation data from CINRAD/SA radar combined with ground observation and sounding data,7 severe convective storms triggered by mesoscale convergence lines are analyzed.The results are as follows.1)Boundary layer convergence lines such as gust fronts,sea breeze fronts and cold fronts are manifested as distinct narrow-band echoes on radar reflectivity products under certain environmental conditions.Some of the mesoscale convergence lines cannot get any useful information from radar reflectivity products,but can identify linear convergence zones of radial velocity for low-level radial velocity.2)The first convective thunderstorm principally appears about an hour after narrow-band echoes or distinct radial convergence lines are identified by the radar.3)For the gust front generated by dry-type severe convective storms,its right side is usually the main area of triggering new convection cells,leading to the rightward propagation of new storms.4)For wet-type severe convective storms,the direction of new convection cells triggered by the gust front tends to be opposite to the average moving direction of thunderstorms,leading to the back-propagation of new storms.5)The main area of triggering new convection cells lies where the sea breeze front is advancing rapidly inland,and the subsequent thunderstorms have the characteristics of bilateral propagation.6)The low-level linear radial velocity convergence line in appropriate environmental conditions can trigger convection cells and the convective storm moves slowly,which can cause local disastrous heavy rainfall events.

关 键 词：边界层辐合线 窄带回波 雷暴触发 海风锋 

分 类 号：P458.3[天文地球—大气科学及气象学]