Radiative Transfer in Turbid Atmospheres

III. Degree of Polarization of the Solar Radiation Reflected and Transmitted by Turbid Atmospheres

Abstract

The degree of polarization of the radiation diffusely reflected and transmitted by a turbid atmosphere is calculated taking into account the effects of inhomogeneity of the atmosphere at wavelengths of 0.45μ and 0.70μ. The aerosols are presented by particles with refractive index of 1.33 and with radii according to the continental model compiled by Manson. The largest size of radius in this study, however, is taken to be 3.0μ. Three cases of the turbidity condition including pure Rayleigh scattering are considered. Dependence of polarization upon the solar zenith angle, surface albedo, wavelength and aerosol amount is presented. General results are in good agreement with observational data. Comparison between measured and theoretical values for the dispersion (i.e., wavelength dependence) of polarization suggests the value of refractive index of aerosols to be larger than 1.33.