边界层风廓线雷达资料在北京夏季强降水天气分析中的应用

Application of Airda-3000 Boundary Wind Profile Radar in Analyzing Summer Heavy Rainfall in Beijing

利用北京城区及周围3个站的Airda 3000边界层风廓线雷达提供的风廓线资料,详细分析了北京2005年8月3日的一次强降水天气过程。分析表明,降水前十几小时出现双层低空急流,急流层内结构复杂,呈现多中心结构。风廓线观测揭示,由高空槽和弱冷空气共同诱发产生的切变线低涡是产生此次暴雨天气的主要中尺度系统,暴雨系统有很复杂的垂直结构。强降水开始前数小时(夜间)城区地面风场辐合,在临近降水和降水开始时辐合(或切变)层向上发展,这一过程有利于降水的发展。

The heavy rainfall process occurred on 3 August 2005 in Beijing is analyzed in detail by means of the Airda-3000 boundary wind profiler data from three stations in the Beijing urban and suburb areas. Results show that about 10 or more hours before the process started, there appeared doubled low-level jets, which had a complex structure with multiple centers. The wind profiler data show that the process had a complex vertical structure, the main mesoscale system of which was a vortex on the shear line induced by a high-level trough and weak cold air; the surface wind convergence in the urban area started several hours before the heavy rainfall （nighttime）; and the upward propagation of the convergence （shear） layer began at the beginning of rainfall, which was helpful to the development of the process.