云南洱海流域一次暴雨过程的雨滴谱特征分析  

Raindrop Spectrum Analysis of a Rainstorm Process in Yunnan Erhai

作　　者：陈焘 赵婧 张振秀 严天鹤 杨葳葳 易小蓉 CHEN Tao;ZHAO Jing;ZHANG Zhenxiu;YAN Tianhe;YANG Weiwei;YI Xiaorong(Dali Meteorological Bureau,Dali 671000,China;Nanjian Meteorological Bureau,Dali 671000,China)

机构地区：[1]大理州气象局,云南大理671000 [2]南涧县气象局,云南大理671000

出　　处：《三峡生态环境监测》2023年第4期75-81,共7页Ecology and Environmental Monitoring of Three Gorges

基　　金：云南省气象局科研项目(YZ202331);云南省气象局人工影响天气技术研究及效果评估创新团队(2022CX07)。

摘　　要：利用激光雨滴谱仪、自动雨量站和新一代多普勒天气雷达观测资料,对切变线影响下洱海流域的一次暴雨过程雨滴谱特征进行了分析。结果表明:雨强大于2.5 mm/h时,激光雨滴谱仪计算的累计雨量和雷达反射率因子较自动雨量站测得的值存在明显的高估现象,但二者变化趋势基本一致。对雨滴分钟速浓度、雨强和质量加权直径时序分布进行对比分析,发现雨强小于2.5 mm/h时,质量加权直径均值为1.016 mm,雨强大于2.5 mm/h时质量加权直径均值为1.74 mm,粒径大于1 mm的雨滴是影响雨强大小的关键。对本次降雨过程按层云、积云和混合云降水进行分类,发现三类降水的雨滴谱分布均为单峰型,且Gamma分布拟合效果较好,拟合决定系数R2均大于0.9,积云降水谱宽最大至3.75 mm,混合云降水谱宽2.75 mm次之,层云降水谱宽最小为2.125 mm。对Z-R关系进行了拟合,得出本次暴雨过程Z-R关系为Z=118.37R2.32。The characteristics of raindrop spectrum of a rainstorm process in Erhai basin under the influence of shear line were ana⁃lyzed by using the observation data of laser raindrop spectrometer,automatic rainfall station and new generation Doppler weather ra⁃dar.The results show that the cumulative rainfall and radar reflectivity factor calculated by laser raindrop spectrometer were obvi⁃ously overestimated compared with those measured by automatic rainfall station when the rainfall intensity was greater than 2.5 mm/h,but their trands were basically consistent.The time series distribution of minute velocity concentration spectrum,rainfall in⁃tensity and mass-weighted diameter of raindrop spectrum were compared and analyzed.It was found that the mean value of massweighted diameter was 1.016 mm when the rainfall intensity was less than 2.5 mm/h,and the mean value of mass-weighted diame⁃ter was 1.74 mm when the rainfall intensity was greater than 2.5 mm/h.The raindrop with a diameter greater than 1 mm was the key factor affecting the rainfall intensity.The rainstorm process was classified by stratus,cumulus and mixed cloud precipitation.It was found that the raindrop spectrum distribution of the three types of precipitation was unimodal,and the Gamma distribution fit⁃ting effect was better,the fitting coefficient of determination R2 was greater than 0.9.The width of cumulus precipitation spectrum was the largest at 3.75 mm,followed by mixed cloud precipitation,at 2.75 mm,and the width of stratus precipitation spectrum was the smallest,at 2.125 mm.The Z-R relationship was fitted,and Z=118.37R2.32 for the rainstorm porcess.

关 键 词：雨滴谱 GAMMA分布 Z-R关系 

分 类 号：P426[天文地球—大气科学及气象学]