局地强对流天气分析中非常规探测资料应用

Application of Non-Conventional Observational Data to Local Heavy Rain Analysis

应用多种非常规观测资料对2006年6月27日夜间北京地区一次局地强对流天气过程进行了分析。结果表明:直接造成此次暴雨过程的天气系统是两个局地生成的中尺度对流云团,地面中尺度辐合线是降水主要触发机制之一,城市热岛效应为强对流天气的发生提供了有利的热力条件。微波辐射计观测量对降水的发生具有较好的指示意义,液态水含量的急剧增(减)过程,预示着降水即将出现(消亡)。风廓线雷达的连续观测能够部分揭示影响系统的细节特征,从风场配置上可以看到中低层的风切变以及降水前低层的暖平流和小尺度低涡环流,这种系统结构和配置对降水的形成和维持有着重要的意义。

By means of several non-conventional observational data, a local severe convective weather even on June 27 2006 in Beijing is studied. The results show that two meso-scale convective cloud clusters and the surface meso-scale convergence line played the triggering role in the heavy rain process, and the urban heat island provided the thermodynamic condition. The measurements of the ground-based 12-channl microwave radiometer have good indicative significance to the occurrence of heavy rainfall. The rapid increase （decrease） of Liquid Water Content can be used as an indicator in forecasting the beginning （ending） of heavy rainfall. The continuous observation data from wind profile radar can provide detailed information about a convective system partly, such as the lower- and middle-level wind shears, warm advection, and small-scale low-pressure systems, which are of significance to the formation and maintenance of heavy rainfall.