Fast yet accurate computation of the complete radiance distribution in the coupled atmosphere–ocean system

The iteration of the source-function technique is used in conjunction with the discrete ordinate radiative transfer (DISORT) method to derive analytic solutions for the radiances at arbitrary polar angles and arbitrary levels in a multiple scattering (random) medium consisting of two strata with a change in the index of refraction across the interface between them. The atmosphere overlying a body of water (the ocean) serves as a prime example of such a system consisting of two adjacent strata with different indices of refraction. The accuracy of the solutions is tested by considering the coupled atmosphere–ocean system where absorption and scattering by molecules and particles are included. The tests show that these analytic solutions are superior to a spline interpolation that has been used previously in connection with the DISORT method applied to a random medium consisting of two strata with different indices of refraction.