舟曲“8.8”暴雨云团的中尺度特征

摘要

通过对造成舟曲＂8.8＂暴雨的对流云团特征进行分析,发现2010年8月7日20时700 hPa上位于平凉—定西—甘南中部一线的切变线对造成这次暴雨过程的对流云团的形成、发展和维持有十分重要的作用,同时对流云系的发展、加强与2次对流云团的合并有密切关系;舟曲＂8.8＂暴雨是在对流云团减弱南移的过程中发生的,具有明显的局地性和突发性特点;对流云团的移动除受高空引导气流的影响外,地形及由于地形原因形成的山谷风也有非常重要的作用,由于山谷风形成的辐合为对流云团的维持提供了水汽和能量。%The characteristics of the convective cloud in ＂8.8＂ heavy rain process was analyzed in this paper.Results show that the shear line on the upper air chart of 700 hPa located in the middle of Gansu Province played an important role in the convective cloud＇s formation,development and maintenance,and at the same time,the two time coalition of convective cloud had a very close relationship for the convective cloud＇s development.The heavy rain occurred in the process of convective cloud subsiding and moving southward,the heavy rain showed an obvious regional and abrupt characters.The moving path of the convective cloud was effected by the steering flow,topography and mountain and valley winds.The convergence resulted by the mountain and valley winds supplied the water vapour and energy to the maintenance of the convective cloud.