Flux and Polarization Calculations of the Radiation Reflected from the Clouds of Venus

Abstract

The flux and polarization reflected from a spherically symmetric planetary atmosphere is calculated by the Monte Carlo technique. Spherical geometry is used throughout the calculation with no plane- parallel approximations. The scattering angle for the photons is chosen from an appropriate singlescattering function calculated from Mie theory. The photons are followed through all orders of multiple scattering. Models considered for the Venus atmosphere include several single-layered models with various particle size distributions and one multilayered model. The results, when compared with experimental observations, suggest that the clouds are composed of particles having a mean radius of the order of I M and a refractive index in the range from 1.45-1.6. Differences between theory and experiment may result from aspherical particles and a variation of the composition and size distribution of the particles with height in the atmosphere.