基于雷达反射率因子的降水性层状云中雨滴谱参数的反演方法与检验研究

A RETRIEVAL METHOD AND VERIFICATION OF PARAMETERS OF RAINDROP SIZE DISTRIBUTIONS OF PRECIPITATING STRATUS CLOUDS FROM RADAR REFLECTIVITY FACTORS

对基于雷达反射率因子观测数据的层状云降水粒子谱参数反演算法进行研究。(1)给出层状云降水粒子谱参数的反演理论和反演算法流程;(2)选取吉林省伊通县的一次降水层状云过程进行反演试验和验证分析,利用雷达反射率因子观测数据反演得到雨滴平均直径和数浓度参数,并用放置在伊通县气象局观测场中的Parsivel激光雨滴谱仪的实测数据与近地层反演结果进行对比。结果发现,通过反演算法计算得到的滴谱与实测滴谱的变化趋势基本相同,而且反演的雨滴平均直径和数浓度在量级和数值上的大小与实测数据具有良好的一致性,说明该反演方法用于从现有天气雷达回波强度数据中挖掘出降水性层状云的微物理参数是可行的。

Cloud particle phase and their median diameters are vital parameters. In this paper, a research of inversion is conducted on an algorithm for raindrop spectrum of stratus cloud based on radar reflectivity factor. The inversion algorithm and process are given. The radar reflectivity factor, observed in Yitong County in Jilin Province in northeastern China, is used in the inversion tests, and then verification and analysis are given. Then the mean diameters and number concentrations of raindrop can be calculated with the radar reflectivity to compare with the observations observed by Parsivel laser optical disdrometer in the same place. The result shows that the variation trend between the drop-size distribution calculated with the inversion algorithm and the observation is almost the same. The magnitude and value of mean diameters and number concentrations of raindrops are almost equal. Therefore the results above show that the proposed inversion method, which is used to retrieve microphysical parameters of precipitating stratus clouds on the basis of the plentiful echo intensity data from widely used weather radars, is feasible.