青藏高原东坡不同海拔区域的雨滴谱特征  

The Characteristics of Raindrop Spectrum in Different Altitude Region on the Eastern Slope of Qinghai-Xizang Plateau

作　　者：李山山 王晓芳[1] 万蓉[1] 李国平[2] LI Shanshan;WANG Xiaofang;WAN Rong;LI Guoping(Hubei Key Laboratory for Heavy Rain Monitoring and Warning Research,Institute of Heavy Rain,CMA,Wuhan 430205,Hubei,China;College of Atmospheric Sciences,Chengdu University of Information Technology,Chengdu 610225,Sichuan,China)

机构地区：[1]中国气象局武汉暴雨研究所,暴雨监测预警湖北省重点实验室,湖北武汉430205 [2]成都信息工程大学大气科学学院,四川成都610225

出　　处：《高原气象》2020年第5期899-911,共13页Plateau Meteorology

基　　金：国家自然科学基金项目(91637211,41620104009,41975058);湖北省气象局科技项目(2019Z03)。

摘　　要：利用2018年6-8月川西高原四个不同海拔站点DSG5型降水现象仪的雨滴谱观测数据,对高海拔、大梯度陡峭地形条件下的雨滴数浓度、微物理特征参量和雨滴下落速度进行了对比分析。结果表明:不同海拔上,雨滴数浓度平均谱符合Gamma函数分布,弱降水和强降水表现出完全不同的雨滴谱特征。弱降水中,随海拔的升高,小雨滴粒子(直径D<1 mm)的数浓度增大,中等直径粒子(1 mm<D<3 mm)的数浓度反而略有减小;雨滴粒子的数浓度Nw增大,平均直径Dm减小。强降水中,随海拔的升高,小粒子和中等直径粒子的数浓度减小,大粒子(D>3.25 mm)的数浓度明显增大;雨滴粒子的数浓度Nw减小,而平均直径Dm快速增大。中等强度降水是大粒子和小粒子数目的转换阶段。不同雨强等级高海拔雨滴下落速度都大于低海拔。Using raindrop spectrum data observed with four DSG5 precipitation phenomenon instruments deployed at different altitudes in western Sichuan Plateau from June to August 2018,the raindrop number concentration,several microphysical parameters and falling velocity at different regions with high altitude and steep terrain were compared and analyzed.The results show that:The average raindrop spectrums at different altitudes are in good agreement with the Gamma distribution,while completely different characteristics of raindrop spectrum are found between weak and strong rainfall types.For the weak rain types,with increasing altitude,the raindrop number concentration of small particles(D<1 mm)increases and medium diameter particles(1 mm<D<3 mm)decreases slightly.The number concentration Nw increases and the average diameter(Dm)decreases with altitude.For the strong rain types,with increasing altitude,the raindrop number concentration of small and medium particles decreases and larger particles(D>3.25 mm)increases significantly.The number concentration Nw decreases and the average diameter(Dm)increases rapidly.The medium rain types are found to be the conversion phase of raindrop numbers between small and large particles.The falling velocity observed at higher altitude locations is greater than lower altitude in all types of rainfall.

关 键 词：川西高原 海拔 雨滴谱 数浓度 平均直径 

分 类 号：P426.62[天文地球—大气科学及气象学]