【作者】 方志华； 刘兆荣； 白郁华； 李金龙；

【Author】 Fang zhihua Liu zhaorong Bai Yuhua and Li Jinlong (College of Environmental Sciences and Engineering, Peking University, Beijing ,100871)

【机构】 北京大学环境科学与工程学院；

【摘要】 云下清除是大气气溶胶重要的清除机制,清除效果和粒子直径大小及雨强等气象条件密切相关,一般采用质量平均清除系数和雨强的参数化关系来定量描述。本文通过对M-P雨滴谱、雨滴终速经验公式、海盐气溶胶粒径分布函数及雨滴对气溶胶粒子捕获系数等基于雨滴粒径或气溶胶粒径的多个函数进行数值模拟,得到海盐气溶胶粒子的质量平均清除系数和雨强间的参数化关系1Λ(h-1)=0.79·p00.75,在此基础上分析了沿海城市降雨过程中大气海盐气溶胶浓度和雨水中Cl-浓度的变化趋势。更多还原

【Abstract】 Below-cloud scavenging is an important deposition mechanism for airborne aerosol particles. The scavenging coefficient depends on the aerosol size and meteorological conditions, especially the precipitation rate significantly. A study for aerosol scavenging in the washout process was undertaken. With the M-P raindrop size distribution, the empirical formulas calculating raindrop terminal velocity, the log-normal size distribution of aerosol particles and the collision efficiency between single rain droplet and particles which are the functions of the diameter of raindrop or particles, numerical simulation and parameterization between the weighted mean scavenging coefficients of sea salt aerosol particles and rainfall rate was accomplished : 1 Λ (h -1) = 0.79 ? p00.75,which can be applied to analysis the trend of atmospheric aerosol concentration and ion concentration changes of rainwater during precipitation.更多还原