短时强降水和冰雹云降水个例雨滴谱特征分析  

Characteristics of the Raindrop Size Distribution during a Short-time Heavy Rainfall and a Squall Line Accompanied by Hail

作　　者：王俊 王文青[1,2] 王洪 张秋晨 龚佃利 WANG Jun;WANG Wenqing;WANG Hong;ZHANG Qiuchen;GONG Dianli(Key Laboratory for Meteorological Disaster Prevention and Mitigation of Shandong,Jinan 250031,Shandong,China;Shandong Weather Modification Office,Jinan 250031,Shandong,China)

机构地区：[1]山东省气象防灾减灾重点实验室,山东济南250031 [2]山东省人民政府人工影响天气办公室,山东济南250031

出　　处：《高原气象》2021年第5期1071-1086,共16页Plateau Meteorology

基　　金：国家重点研发计划项目(2018YFC1507903);国家自然科学基金项目(41275044);山东省气象局课题(2012sdqx12)。

摘　　要：为了更好地理解暖云和冷云过程影响下雨滴谱和降水积分参数分布特征的差异,利用Parsivel激光雨滴谱仪和CINRADA/SA多普勒雷达观测资料,分析了两次强对流性降水(一次短时强降水和一次伴随降雹的飑线对流带降水)雨滴谱特征,研究表明:(1)短时强降水的对流降水雨滴谱谱型包括单峰谱(峰值直径0.2~0.3 mm)、双峰谱(峰值直径0.9 mm和2.0 mm)和多峰谱(粒子直径1.0 mm和2.0 mm同时出现第二、三峰),显示暖云中雨滴碰并、碰撞-破碎机制对雨滴谱形成有重要影响。归一化Gamma函数的截距参数和平均质量加权直径(lgN_(w)-D_(m))分布显示短时强降水的雨滴谱具有大陆性对流降水特征;Z-R关系与新一代多普勒雷达的Z-R关系接近。(2)伴随冰雹的飑线对流降水雨滴谱主要是单峰谱(峰值直径0.2~0.7 mm),缺少较大直径的第二峰,有较多的小和较大直径粒子,大于峰值直径的粒子分布曲线是向上凹的。lgN_(w)-D_(m)分布显示比大陆性对流降水的雨滴谱有更大D_(m);Z-R关系具有较大的指数和系数,明显偏离新一代多普勒雷达的Z-R关系。表明冷、暖云过程的差异导致地面雨滴谱和积分参数之间有明显不同。(3)尺度律方法分析发现,短时强降水主要雨滴谱的广义函数g(x)可以是指数函数、也可以是形状因子小于1.0的Gamma函数,而伴随冰雹的强降水雨滴谱广义函数更适合形状因子小于0的Gamma函数。To better understand the differences of rain drop size distribution(DSD)and its integral parameters,such as intercept parameter,volume weight diameter,rain intensity and radar reflectivity factor,between warm rainfall and cold rainfall processes,the characteristics of rain DSD during a heavy rainfall and a squall line accompanied by hail(rain intensity higher than 10 mm·h-1)are analyzed based on data observed by Parsivel disdrometers and CINRADA/SA Doppler radars.The results are shown as follows.(1)The DSD of the convective type in heavy rainfall includes single-peak spectrum(peak diameter between 0.2 and 0.3 mm),double peak spectrum(peak diameter being 0.9 or 2.0 mm)and multi-peak spectrum(the second and third peaks appear simultaneously when particle diameter is 1.0 mm and 2.0 mm),indicating that the coalescence and collisionbreakup of raindrops in warm rainfall are dominant processes.The intercept parameter and the mean mass-weighted diameter(lgNw-Dm)of the normalized Gamma function show the continental convective characteristics of rain DSD during the heavy rainfall.The Z-R relationship is close to that of the new generation Doppler radar.Although the heavy rain is fully developed in the high-altitude cold rainfall processes,the collision-coalescence and breakup in the warm rainfall have enough time to operate owing to the high position of 0℃,and the equilibrium DSD appears.(2)The DSD of the convective precipitation accompanied by hail is mainly single-peak spectrum(peak diameter between 0.2 and 0.7mm),lacks the second peak with larger diameter,has more small and large diameter particles,and the curve of DSD larger than the peak diameter is a concave upward.The distribution of lgNw-Dm shows a larger Dm compared with the DSD of continental convective precipitation,while the Z-R relationship has a larger index and coefficient,deviating from that of the new generation Doppler radar.The differences between cold rainfall and warm rainfall processes lead to the obvious differences between ground DSD and integral

关 键 词：强降水 冰雹 雨滴尺度分布谱 尺度律方法 广义分布函数 

分 类 号：P401[天文地球—大气物理学与大气环境]