Refractive effects on transmittance and radiance in the marine surface layer

Near the sea surface, strong gradients of temperature and moisture affect the path taken by propagating radiation. Strong gradients in aerosol properties may also be present causing transmittance and radiance to be strongly dependent on the exact path taken by radiation, especially when viewing angles are nearly horizontal. So far, the rapid changes of atmospheric properties with altitude near the surface have been neglected in the calculations of transmittance and path radiance. In this paper, calculations of transmittances under sub- and super-refraction conditions are presented. It is shown that transmittance can vary significantly when accounting for refraction in platform based or limb viewing conditions. Furthermore, calculations of path-radiance in the surface layer, which accounts for the scattering of incident radiation, will be addressed and computational results presented.