Effect of physical properties of atmospheric aerosols on path radiance

Abstract

Using a set of simplified radiative transfer equations, the effects of the changes in the physical properties (such as columnar size distribution, optical depth and refractive index) of atmospheric aerosols on the upwelling atmospheric path radiance are investigated for a nadir viewing remote sensor at various solar illumination angles in the context of developing operational methods for correcting radiances received by remote sensing satellites for atmospheric effects. It is seen that at low solar illumination angles and high haze conditions (aerosol optical depths > 0.5) the path radiance depends strongly on the nature of the aerosol size distribution, whereas for low to moderate values of aerosol optical depths ( < 0.5), the path radiance increases nearly linearly with optical depths. Spectral variations indicate a large increase in path radiance with decrease in wavelength.