Effect of Varying Aerosol Concentrations and Relative Humidity on Visibility and Particle Size Distribution in Urban Atmosphere  

作　　者：Ummulkhair Abdulkarim Bello Tijjani 

机构地区：[1]Department of Physics,Sa’adatu Rimi College of Education Kano,P.M.B.3218,Kano State,Nigeria [2]Department of Physics,Bayero University Kano,P.M.B.3011,Kano State,Nigeria

出　　处：《Journal of Atmospheric Science Research》2021年第3期14-28,共15页大气科学研究（英文）

摘　　要：Atmospheric aerosol concentrations have been found to change constantly due to the influence of source,winds and human activities over short time periods.This has proved to be a constraint to the study of varied aerosol concentrations in urban atmosphere alongside changing relative humidity and how it affects visibility and aerosol particle size distribution.In this research simulation was carried out using Optical Properties of Aerosols and Clouds(OPAC 4.0)average concentration setup for relative humidity(RH)0-99%at visible wavelength 0.4-0.8μm to vary the concentrations of three aerosol components:WASO(Water-soluble),INSO(Insoluble)and SOOT.The Angstrom exponents(α),the curvatures(α2)and atmospheric turbidities(β)were obtained from the regression analysis of Kaufman’s first and second order polynomial equations for visibility.The research determined the mean exponent of the aerosol size growth curve(μ)from the effective hygroscopic growth(geff)and the humidification factors(γ)from visibility enhancement f(RH,λ).The mean exponent of aerosol size distributions(υ)was determined fromμandγ.The results showed that with varied WASO,INSO and SOOT concentrations respectively at different RH,aerosol particle size distributions showed bimodal characteristics with dominance of fine mode particles.Hazy atmospheric conditions prevailed with increasing turbidity.

关 键 词：Aerosol concentration Humidification factor Hygroscopic growth Particle size distribution Visibility enhancement 

分 类 号：X51[环境科学与工程—环境工程]