辽宁地区不同降水云系雨滴谱参数及其特征量研究

A Study on Characteristics of Spectral Parameters and Characteristic Variables of Raindrop Size Distribution for Different Cloud Systems in Liaoning Province

利用位于辽宁省沈阳市和辽阳市的Parsivel(Particle Size and Velocity)激光雨滴谱仪观测到的雨滴谱资料按照积雨云降水系统、积层混合云降水系统和层状云降水系统分析雨滴谱特征量和谱参数的平均特征及随时间的演变特征。结果表明:Gamma分布拟合谱参数N0和λ按照层状云、积层混合云和积雨云的顺序减小,谱参数μ按照层状云、积层混合云和积雨云的顺序增大;直径小于1 mm的降水粒子对数浓度的贡献最大,直径大于1 mm的降水粒子对雷达反射率的贡献最大;M-P分布的谱参数N0与雨强I具有幂函数关系,并且随着雨强I的增大而增大,谱参数λ与雨强I具有指数函数关系,随着雨强I的增大而减小。

Observations of raindrop size distribution collected at Shenyang and Liaoyang, Liaoning Province, have been exploited to reveal characteristics of characteristic variables and spectral parameters of raindrop size distribution for stratus clouds, cumulus clouds, and stratus clouds embedded in convective systems. Conclusions are as follows. The spectral parameters N0 and λ of Gamma distribution decrease and spectral parameter μ increases in the order of stratus clouds, stratus clouds embedded in convections, and cumulus clouds. Precipitation particles with diameters less than 1 mm contribute most to the number concentration, while precipitation particles with diameters greater than 1 mm make the largest contribution to radar reflectivity. The spectral parameters N0 of M-P distribution and rainfall intensity are fitted by a power function, and results show that the spectral parameter N0 increases with the increase of rainfall intensity. The spectral parameters λ and rainfall intensity are fitted by an exponential function, and the spectral parameters λ decreases with the increase of rainfall intensity.