青藏高原夏季一次冰雹过程的微物理特征  

Microphysical Characteristics of a Summer Hailstorm in Tibetan Plateau

作　　者：强德厚 刘俊卿 丁建芳[3] 程博 吴江 唐利琴 QIANG Dehou;LIU Junqing;DING Jianfang;CHENG Bo;WU Jiang;TANG Liqin(Atmospheric Exploration Technology and Equipment Support Center of Tibet,Lhasa 850000;Weather Modification Center of Tibet,Lhasa 850000;Weather Modification Center of Henan Province,Zhengzhou 450003;Nagqu Meteorological Office of Tibet,Nagqu 852000)

机构地区：[1]西藏自治区大气探测技术与装备保障中心,拉萨850000 [2]西藏自治区人工影响天气中心,拉萨850000 [3]河南省人工影响天气中心,郑州450003 [4]那曲市气象局,那曲852000

出　　处：《气象》2024年第6期701-710,共10页Meteorological Monthly

基　　金：西藏自治区自然科学基金项目(XZ2019ZRG-151);中国气象局创新发展专项(CXFZ2023J042);河南省重点研发与推广专项项目(KP202329)共同资助。

摘　　要：为提高青藏高原冰雹过程中降水特征的认识,利用雨滴谱数据并结合探空、雷达、FY-4A卫星和分钟降水资料,分析了2020年7月23日拉萨降雹过程的微物理特征。结果表明:在降水演变特征方面,雨量计分钟降水量与DSG5降水天气现象仪接近,但开始和结束时间、降水峰值及总降水量略有差异。此次过程中雨滴、冰雹的平均谱分布拟合曲线呈单调下降,雨滴谱符合Γ分布,雹谱符合M-P分布。降雹初期,降水粒子以小粒子居多,主要由雨滴下落中的蒸发所致;降雹后期,降水粒子谱宽变大,碰撞破碎和霰粒融化产生大量的小雨滴引起粒子数浓度剧增,数浓度增多和滴谱变宽导致雨强增大。冰雹的数浓度仅占总降水粒子数浓度的1.6%,但对地面降水量的贡献最大。根据观测,拟合得到冰雹平均末速度与直径的关系公式。In order to improve the understanding of precipitation characteristics of hailstorm in the Tibetan Plateau,based on the raindrop size distribution data observed by DSG5 disdrometer,radar reflectivity,FY-4A satellite and minutely precipitation data,etc.,the precipitation microphysical characteristics of the hailstorm that occurred in Lhasa on 23 July 2020 is analyzed.The results show that there were some slightly differences at the time of beginning and end of the hailstorm,precipitation peak and total precipitation between rain gauge and DSG5 disdrometer although the minutely precipitation amounts of the two were similar.The fitted curves of the average spectrum distribution of raindrops and hailstones were monotonously decreasing.The raindrop size spectrum conformed toΓdistribution and the hail size spectrum accorded with M-P distribution.In the early stage of hail process,the precipitation particles were mostly small,which was mainly caused by the evaporation of the raindrops.In the later stage,the spectral width of precipitation particles became wider,the collision and fragmentation of the particles and the melting of graupel particles produced a large number of small raindrops,leading to a sharp increase in the number of particle concentration.The significant increase of number concentration and the widening of the droplet spectrum in this stage were the reason for the increased rainfall.The number concentration of hailstones only accounted for 1.6%of the total number concentration of precipitation particles,while the hailstones were the major contributors of the surface total precipitation.The empirical formula for the average terminal falling velocity and the diameter of the hails was fitted based on the observation.

关 键 词：青藏高原 冰雹过程 微物理特征 谱分布 

分 类 号：P416[天文地球—大气科学及气象学] P426