Comparison of discrete ordinate and Monte Carlo simulations of polarized radiative transfer in two coupled slabs with different refractive indices.

A comparison is presented of two different methods for polarized radiative transfer in coupled media consisting of two adjacent slabs with different refractive indices, each slab being a stratified medium with no change in optical properties except in the direction of stratification. One of the methods is based on solving the integro-differential radiative transfer equation for the two coupled slabs using the discrete ordinate approximation. The other method is based on probabilistic and statistical concepts and simulates the propagation of polarized light using the Monte Carlo approach. The emphasis is on non-Rayleigh scattering for particles in the Mie regime. Comparisons with benchmark results available for a slab with constant refractive index show that both methods reproduce these benchmark results when the refractive index is set to be the same in the two slabs. Computed results for test cases with coupling (different refractive indices in the two slabs) show that the two methods produce essentially identical results for identical input in terms of absorption and scattering coefficients and scattering phase matrices.

Impact of particulate oceanic composition on the radiance and polarization of underwater and backscattered light.

We use a Monte Carlo model to investigate how the particulate oceanic composition affects the radiance, the linear polarization, and the circular polarization of underwater and backscattered light. The Mueller matrices used in our simulations were computed using the T-matrix method. They are significantly different for organic and inorganic particles. Our Monte Carlo simulations show that these differences have a significant impact on the underwater and backscattered light, and that it may be possible to determine the ratio between the amounts of organic and inorganic particles from measurements of the full Stokes vector.