祁连山北坡一次人工增雨降水过程雨滴谱特征分析  

Raindrop Spectrum Characteristics of an Artificial Precipitation Enhancement Process on Northern Slope of Qilian Mountains

作　　者：庞朝云[1] 李宝梓[1] 张丰伟[1] 陈祺[1] 罗汉 杨瑞鸿[1] PANG Zhaoyun;LI Baozi;ZHANG Fengwei;CHEN Qi;LUO Han;YANG Ruihong(Weather Modification Office of Gansu Province,Lanzhou 730020)

机构地区：[1]甘肃省人工影响天气办公室,兰州730020

出　　处：《气象科技》2021年第4期621-628,共8页Meteorological Science and Technology

基　　金：国家重点研发计划(2019YFC1510302);中国气象局西北区域人影建设研究试验项目(RYSY201901);甘肃省气象局重点项目(Zd2021-03)共同资助。

摘　　要：本文以2020年8月21日在祁连山开展的人工增雨外场试验为例,分析了祁连山北坡雨滴谱特征和增雨作业前后雨滴谱特征参量和谱型的变化。结果表明:虽然此次降水不均匀,但北坡3个试验点微物理参量特征值的演变较接近,平均雨滴谱谱宽均较小,谱型基本一致,均为单峰型,峰值出现在0.5mm左右。Gamma分布对雨滴谱的拟合效果较好,分布曲线能较准确地反映实际雨滴谱的分布形态,但在峰值段(0.5mm)拟合值有偏差,拟合结果略小于实测谱。Z-I之间满足对数相关,拟合优度R2值都在0.86以上,有较好的拟合关系。作业后雨滴尺度、总数浓度、雨强等均出现增大趋势,作业后雨滴谱的谱宽逐渐增大,作业后10min,峰型由单峰转变为双峰,作业后30min、60min,谱宽持续增大,说明此时云内小雨滴间的碰并过程开始出现,产生了较大尺度的雨滴。Based on the observation data from an artificial precipitation enhancement field experiment,which was carried out on 21 August 2020 in the Qilian Mountains,the characteristics of the raindrop spectrum on the northern slope of the Qilian Mountains and the changes of raindrop spectrum characteristic parameters and spectrum types before and after the precipitation enhancement operation are analyzed.The results show that the precipitation was uneven,but the microphysical parameter eigenvalues of the three observation stations on the northern slope were relatively close.The average raindrop spectral widths were small,and the spectral patterns were basically the same,all of which were unimodal.The peak appeared at about 0.5 mm.The Gamma distribution had a good fitting effect on the raindrop spectrum.The distribution curve can more accurately reflect the distribution of the actual raindrop spectrum,but the fitting value in the peak section(0.5 mm)was biased,and the fitting result was slightly smaller than the measured spectrum.The Z-I relation satisfied the logarithmic correlation;the goodness-of-fit R2 was above 0.86;and there was a good fitting relationship.After the operation,the raindrop size,total concentration,rain intensity,etc.all show an increasing trend.After the precipitation enhancement operation,the spectrum width of the raindrop spectrum gradually increased.The peak shape changed from single peak to double peak 10 minutes after the operation.The spectrum width continued to increase 30 minutes and 60 minutes after operation,indicating that the collision process between small raindrops in the cloud began to occur at this time,resulting in larger-scale raindrops.

关 键 词：祁连山 雨滴谱 微物理参数 Gamma拟合 

分 类 号：P426[天文地球—大气科学及气象学]