Abstract:

Based on the routinemeteorological data and the Dopp ler radar date, the causes of a hail p rocess occurred on August 2, 2006 in Qingyang were analyzed from the synop tic environment, physical quantity field and the characteristics ofDopp ler radar echoes. Results show that itwas a typ ical northwest flow pattern at the level of 500 hPa, the lower air convergence and the upper air divergence,the coup ling of the positive vortex in themiddle troposphere led to the liftingmovement develop ing in the low level, and thiswas advantageous to the upward transportation of the local water vapor; the short wave trough at the north of Hetao area caused the cold air to move down and this became the main triggeringmechanism of this p rocess. The Dopp ler radar data analysis showed that the p rocess occurred after a strong convection cloud which created by a squall line, and there was a good corresponding relationship between the change of the cloud top temperature and the development of the convection cloud; the merge of the single cloud cluster was advantageous to the energy enhancement and easy to p roduce the hail.

Key words: hail , synop tic environment, physical quantity field , Dopp ler radar echoes

摘要：

:利用常规气象资料和多普勒雷达资料,从天气形势、物理量场和雷达回波演变特征3方面分析了2006年8月2日庆阳市局地强降雹的天气过程。结果表明:此次降雹过程在500 hPa高空环流形势场上呈典型的西北气流型,低层辐合、高层辐散,对流层中层正涡度区的耦合激发低层上升运动加强,有利于本地水汽向上输送;河套北部短波槽促使冷空气动力下传是这次局地强对流天气最主要的动力触发机制;从雷达回波的演变来看此次降雹并非是典型的冰雹云回波特征,而是由飑线造成的对流云相互碰并增强后产生的冰雹;同时卫星云图上云顶亮温的变化与对流云团的发展也有着很好的对应关系,单个云团的合并有利于能量的集中和加强,易于产生冰雹。
　

关键词: 冰雹, 天气形势, 物理量场, 雷达回波