The radiative transfer equation has been solved by a Monte Carlo technique for a flat homogeneous ocean with two different incident radiance distributions. The irradiance reflectivity R for photons that penetrate the ocean is presented as a function of the single scattering albedo ω0, and the scattering phase function P(θ) of the medium. The P(θ)’s used are based on experimental observations. The results clearly show that R depends strongly on both ω0 and P(θ) but apparently not on the form of the incident radiance distribution. Arguments are presented to show that in clearest ocean water the upwelling field above the surface can provide information only about the upper 25 m of the medium.
Howard R. Gordon and Otis B. Brown, "Irradiance Reflectivity of a Flat Ocean as a Function of Its Optical Properties," Appl. Opt. 12, 1549-1551 (1973)