基于二维视频粒子谱仪(2DVD)观测的北京降雪微物理特征研究
Winter Snowfall Microphysics Characterized by a 2-D Video Disdrometer(2DVD)in Beijing
摘要
Abstract
The study of snow microphysics holds great significance in understanding the mechanism of winter precipitation and optimizing the cloud microphysical parametrization scheme in the weather model.However,at present,very few studies have analyzed the microphysical characteristics of snowfall in China.To thoroughly understand the microphysical characteristics of snowfall in Beijing,this paper presents a detailed analysis of particle size distributions(PSDs),fall velocity(V),snow density(ρ)and aspec ratio(AR),and their relationships with equivalent diameter(D)for six snowfall events,using data from a 2D video disdrometer(2DVD).The results are as follows:(1)The density of snow particles with a median volume diameter(D0)less than 1.5 mm is lower than values reported in other literature.The coefficient in the V(D)relationship is related to density,increasing with it,and the terminal velocity is slightly greater than that observed in Colorado but less than that in Nanjing.(2)The 5-minute PSDs for each case align well with the exponential and normalized gamma distribution models.The temporal variations of the slope parameter(Λ)and the concentration parameter(N0 for exponential,Nw for gamma)were generally consistent between the two models,while the snowfall rate(SR),total number concentration(Nt)and D0 calculated from gamma PSD are better consistency with the direct 2DVD measurements.(3)Introducing density(ρ)into the Nw-D0 relationship improved the correlation.(4)This study presents the first measurements of snowflake aspect ratio for Beijing,showing a mean ar of 0.76 and a tendency to approach 1 for diameters more than 2.5 mm,in agreement with other studies.(5)When the radar reflectivity(Ze)is constant,an increase in SR is accompanied by a decrease in D0 and increases in Nw and ρ.Conversely,when SR is constant,an increase in Ze is closely related to an increase in D0 and decreases in ρ and Nw.Compared to the Ze-SR relationship derived for Nanjing,the relationship obtained in this study(Ze=851 SR1.33)gives lower SR estimates for the same Ze.These features demonstrate that quantitative snowfall estimation using radar entails greater uncertainty compared to quantitative rainfall estimation.关键词
冬季降雪/微物理特征/二维视频粒子谱仪(2DVD)/雪花密度/轴比/Ze-SR关系Key words
Snowfall/Microphysical character/Two-dimensional video disdrometer(2DVD)/Snowfall density/Aspect ratio/Ze-SR relation分类
大气科学引用本文复制引用
罗丽,陈羿辰,于田甜,陈明轩,仰美霖,肖辉..基于二维视频粒子谱仪(2DVD)观测的北京降雪微物理特征研究[J].大气科学,2025,49(5):1387-1406,20.基金项目
北京市自然科学基金项目8222053,国家自然科学基金项目42005109,中央级公益性科研院所基本科研业务费专项基金项目IUMKY20243,北京市科协 2022～2024年度青年人才托举工程项目,北京市局科技项目BMBKJ202201006,中国气象局智能气象观测技术重点开放实验室2024年度开放研究课题ZNGC2024QN10 Beijing Natural Science Foundation(Grant 8222053),National Natural Science Foundation of China(Grant 42005109),Special Fund of Chinese Central Government for Basic Scientific Research Operations in Commonweal Research Institutes(Grant IUMKY202432),Talent Nurturing Program of Beijing Association for Scientific and Technology during 2022-2024,Science and Technology Project of Beijing Meteorological Bureau(Grant BMBKJ202201006),Open Research Fund Project of the Key Laboratory of Intelligent Meteorological Observation Technology,China Meteorological Administration(Grant NGC2024QN10) （Grant 8222053）
