This project concerns the analysis of data on the angular patterns of sunlight reflected by the snow surface at all wavelengths, obtained from prior fieldwork at Dome C Station on the East Antarctic Plateau. The interactions of solar radiation with the snow surface, with clouds, and with atmospheric gases, will be computed to infer shortwave cloud radiative forcing at both the surface and the top of the atmosphere. Using the surface measurements as the lower boundary condition, the spectral and broadband albedo at the top of the atmosphere will be modeled and compared to those obtained from satellite measurements of the Earth Radiation Budget by the CERES (Clouds and the Earth's Radiant Energy System) instruments, and will be used to support studies of the Earth's radiation budget. These studies will include the enhancement of forward-reflected radiation by clouds over snow, and the relation of angular scattering pattern and the albedo at the surface to those at the top of the atmosphere. An additional important aspect will be the study of the effect of clouds over snow on the absorption of solar radiation in the atmosphere, using spectral radiative transfer modeling, based on the measurements of the snow reflectance.
