Determination of Effective Absorption Property of Atmospheric Aerosols and Validity of that Value in Calculating the Flux Divergence. Part I Theory

[摘要] A method of estimating the effective absorption property of atmospheric aerosols is proposed. This method is based on the dependence of reflectance of solar radiation at some altitudes on aerosol refractive index. Sensitivity studies of the monochromatic and entire solar spectrum reflectance to various radiative parameters show that this method has enough sensitivity to estimate the absorption property. This effective value may be different from the real value for an individual particle. To assess the validity of the effective value in radiative transfer calculation, modeling studies are performed, that is, some uncertainties due to complicated features, such as refractive index depending on radius and wavelength, non-Lambertian surface and wavelength dependence of the surface reflectivity are examined with a numerical model. The results indicate that these are small effects on the estimation and the effect of aerosols on earth-atmosphere radiation field can adequately be described by the effective values.

[学科分类] 大气科学