基于雨滴谱的增雨作业微物理特征分析

Microphysical Characteristics of Precipitation Enhancement Operations Based on Raindrop Spectrum

针对2018年3月16—17日四川盆地西北部一次典型层状云降水天气过程,利用云模式、卫星、雷达、探空等资料,分析了人工增雨作业条件和物理响应。同时,基于雨滴谱观测数据开展了人工增雨作业微物理特征分析,重点研究了粒径速度谱分布特征。结果表明:人工增雨作业后,不同粒径、不同粒速的粒子数变化明显,大滴粒子显著增多,雨滴谱变宽,0.437~1.625mm粒径谱和1.5~5.2m/s速度谱明显变宽;同时,粒径和粒子速度无明显跃变,区间值分布相对集中在粒径0.312~2.125mm、粒速1.1~6.8m/s,人工增雨作业对降水粒子的粒径和粒子速度改变有限。人工增雨作业影响时段,降水强度和雨含水量以及总数浓度和有效粒径,依然保持与自然降水时段各自峰值、谷值、震荡态势的一致性,人工增雨作业不改变各物理量之间的相关性。

Based on a typical stratiform cloud precipitation weather process in the Northwest Sichuan Basin from 16 to 17 March 2018,the conditions and physical responses of artificial precipitation enhancement operations are analyzed by using the cloud model results,satellite images,radar echoes,and sounding data.Meanwhile,based on the observation data of raindrop spectra,the microphysical characteristic response analysis of artificial precipitation enhancement operations is carried out,and the distribution characteristics of particle size velocity spectra are mainly studied.The results show that:after the rainfall enhancement operations,the number of particles with different particle diameters and different particle speeds changed significantly;large particles increased obviously;the raindrop spectra widened;and the0.437-1.625 mm diameter spectrum and 1.5-5.2 m/s speed spectrum became significantly wider.Meanwhile,there was no obvious jump in particle size and particle velocity.The interval value distribution relatively concentrated in the particle size of 0.312 to 2.125 mm with the particle velocity of 1.1 to6.8 m/s.The artificial precipitation has a limited influence on the size and velocity of precipitation particles.During the influence period of artificial rain enhancement operations,the intensity of precipitation,rain water content,total number concentration and effective particle size remained consistent with their respective peaks,valleys,and oscillations,as that of the natural precipitation period.Artificial precipitation does not change the correlation between the physical quantities.