CAJ | 학술논문

云下清除是大气气溶胶粒子一个重要的清除机制,清除效果与粒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.本文采用数值计算方法模拟气溶胶粒子的云下清除过程,综合考虑布朗扩散、拦截作用和惯性碰撞等机制的贡献,结合不同模态气溶胶粒子的化学成分,在Maple平台上,通过对M-P雨滴谱、雨滴终速经验公式、气溶胶粒子对数正态分布谱、雨滴对气溶胶粒子捕获系数等,基于雨滴或气溶胶粒径的多个函数进行统一符号处理和数值计算,得到CaCO3、(NH4):SO4两种典型的大气气溶胶粒子质量平均清除系数和雨强的参数化关系:CaCO3粒子为 (h-1)=0.83·P00.74,(NH4)2SO4粒子为 (h-1)=1.8×10-3·P00.64.分析r降雨过程中大气气溶胶质量浓度和雨水中Ca2+,NH4+,SO42-离子浓度的变化趋势.
운하청제시대기기용효입자일개중요적청제궤제,청제효과여립경대소급우강등기상조건밀절상관,일반채용질량평균청제계수화우강적삼수화관계래정량묘술.본문채용수치계산방법모의기용효입자적운하청제과정,종합고필포랑확산、란절작용화관성팽당등궤제적공헌,결합불동모태기용효입자적화학성분,재Maple평태상,통과대M-P우적보、우적종속경험공식、기용효입자대수정태분포보、우적대기용효입자포획계수등,기우우적혹기용효립경적다개함수진행통일부호처리화수치계산,득도CaCO3、(NH4):SO4량충전형적대기기용효입자질량평균청제계수화우강적삼수화관계:CaCO3입자위 (h-1)=0.83·P00.74,(NH4)2SO4입자위 (h-1)=1.8×10-3·P00.64.분석r강우과정중대기기용효질량농도화우수중Ca2+,NH4+,SO42-리자농도적변화추세.
Below-cloud scavenging is an important deposition mechanism for airborne aerosol particles. The scavenging coefficient de-pends on the aerosol size and meteorological conditions, Especially the precipitation rate significantly. The traditional bulk parameter-ization represents the mean wet scavenging coefficient for the whole aerosol size range. This parameterization overestimates the scaven-ging of aerosol mass and ion concentration of rainwater during a heavy or medium precipitation. In this study, the scavenging of aerosol particles in the below-cloud scavenging process was simulated, considering the contribution of collection mechanisms due to Brownian diffusion, directional interception and inertial impaction and the chemical composition of different mode aerosols. With the application of Maple software, multi functions based on either rain drop diameter or aerosol diameter were mathematically simulated and symbol processed. Those included the Marshall-Palmer raindrop size distribution, the raindrop terminal velocity, the log-normal size distribu-tion of aerosols of selected chemical composition and the collision efficiency between a single rain droplet and particles. The reLation-ship between the weighted mean scavenging coefficients of typical coarse and fine aerosol particles and the rainfall intensity were param-eterized. The new parameterization for CaCO3 and (NH4)2SO4 were determined as (h-1) =0. 83 · P00.74 and (h-1) = 1.8 × 10 -3 · P00.64 respectively. The predicted aerosols mass concentration in the air and the concentration variation trend of Ca2+ , NH4+ and SO42- in the rainwater were analyzed based on the above simulation.