title: Ocean-color model incorporating transspectral processes.
abstract: Ocean color is determined by spectral variations in reflectance at the sea surface, which in turn result from both elastic and inelastic processes. We extend an elastic-scattering model of sea surface reflectance to deal with Raman scattering, which is an inelastic process. The analytic solutions are derived for a vertically homogeneous and optically deep water column. The model presented here is based on the quasi-single-scattering approximation of Gordon [Appl. Opt. 12, 2803 (1973)] and is an extension of the model of Sathyendranath and Platt [Appl. Opt. 36, 2620 (1997)]. The Raman-scattering model includes a first-order Raman-scattering term and four second-order terms. Two of the second-order terms result from a combination of an elastic and a Raman-scattering event, whereas the other two second-order terms result from two Raman-scattering events. We show that the contribution to reflectance from these last two terms is typically of the order of 1% of the first-order Raman-scattering term. Therefore these terms and higher-order terms can be neglected for most applications. Issues related to the implementation of the model are discussed, with special reference to remote-sensing applications. Results from the analytic model are compared with Monte Carlo simulations of reflectance at the sea surface.
authors.forename: S
authors.initials: S
authors.lastname: Sathyendranath
authors.forename: T
authors.initials: T
authors.lastname: Platt