天津地区一次冰雹天气触发机制分析

Analysis on Triggered Mechanism of a Hail Weather in Tianjin

[目的]分析2011年7月10日发生在天津市地区的一次冰雹天气的触发机制。[方法]利用Micaps、自动站资料、探空观测资料以及多普勒雷达资料,对2011年7月10日发生在天津市西青区杨柳青镇大柳滩村的一次冰雹天气过程进行个例分析,探讨此次天气的触发机制。[结果]此次过程是由海风锋与地面辐合区相配合所触发的超级单体降雹过程;高空形势位于冷涡底后部的前倾槽前,有利于强对流天气的发展;地面图上位于高压底后部偏东气流有水汽输送,同时存在辐合区;0℃层以上为湿层,并且有较强的上升运动,有利于冰雹的形成与发展。海风锋从海洋向内陆移动带来丰富的水汽、弱冷空气和抬升作用,弥补了中低层的不利条件,当其移动到地面辐合区时可触发强对流天气;多普勒天气雷达能够监测到此次渤海湾海风锋与局地的地面辐合区触发演变为冰雹天气的整个过程。[结论]该研究对判断冰雹过程有明显的指示意义。

[Objective] The research aimed to analyze triggered mechanism of a hail weather in Tianjin on July 10,2011.[Method] Using Micaps data,automatic meteorological observation data,sounding data and Doppler radar data,a hail process rarely happened in Daliutan Village,Yangliuqing Town,Xiqing District,Tianjin City on July 10,2011 was analyzed.Triggered mechanism of the weather was discussed.[Result] The hail weather was generated by super monomer which was triggered by sea breezed front and ground convergence interaction.Upper situation was in front of the forward titled trough at rear of the cold vortex bottom,which was favorable for development of the strong convective weather.On ground map,water vapor transportation existed in easterly airflow at rear of the high-pressure bottom.Meanwhile,convergence zone also existed.It was wet layer over 0 ℃ layer,and strong ascending motion existed,which was favorable for formation and development of the hail.Sea breezed front brought rich moisture,weak cold air and lifting effect when it moved toward inland from ocean,to make up for adverse conditions at low and middle layers.It could trigger a severely convective weather when moved to surface convergence zone.Doppler weather radar could monitor entire hail evolution process.[Conclusion] The research had obvious guidance significance for judging hail process.