Influence of single scattering albedo on reflected and transmitted light from clouds

The dependence of the reflected and transmitted light from clouds on the single scattering albedo omega(0) is studied. The multiple scattered path of the photon in the cloud is accurately simulated by Monte Carlo techniques. When the cloud is optically thin and the surface albedo A = 0, the reflected and transmitted radiances vary nearly as omega(0) for fixed angles of incidence and observation and they depend strongly on the value of A. As omega(0) becomes small and for optically thick clouds, the reflected radiance approaches more closely the value calculated from the single scattering function. As the absorption increases, the transmitted radiance at the zenith becomes larger relative to the value near the horizon. Also, as the optical thickness increases, the maximum of the transmitted radiance moves from the incident direction toward the zenith. The variations in the flux, cloud albedo, and the mean optical path are also discussed.