多普勒雷达可以提供降水回波区的风场信息。为了充分运用雷达资料分析中小尺度天气过程,本文假设反射率因子在短时间内的运动满足拉格朗日守恒,提出了采用连续两次的反射率因子回波和径向速度数据共同约束的方法来反演风场,在反演过程中避免了对径向速度的分布进行假设。针对连续两个时次之间反射率回波运动中产生的不同程度的误差做了模拟风场试验,结果表明,当回波运动随机误差不超过40%时,反演结果较为可靠。另外,本文还利用此风场反演方法进行两次中尺度天气过程的实例分析。结果表明,该方法反演的风场与实际风场结构相符,具有一定的应用价值。

Doppler radar is capable of providing wind field information of precipitation echoes, and this makes it a powerful tool for the study of mesoscale weather processes. Assuming the change of radar reflectivity in a short time comply with the Lagrangian conservation, this paper proposes a new wind field retrieval method by which both radar reflectivity echoes and radial velocity data are used in the retrieval. Avoiding to assume the distribution of radial velocity in the retrieval, this method is theoretically applicable to all kinds of wind fields. This method is applied in two wind field simulation experiments, which use two temporally consecutive reflectivity echoes motions, and errors are generated. Error analysis shows that the retrieval results are more reliable when random error of the echo motion is less than 40%. Additionally, this method is used to analyze two mesoscale weather processes. The agreement between the wind retrieval results and the actual wind field structure proves the feasibility of this method in practice.