A parameterization of spectral and broadband ocean surface albedo

Over two thirds of the Earth's surface is covered by water. The ocean surface albedo (OSA) varies significantly with wavelength, solar elevation, optical depth of clouds and aerosols, wind speed, and constituents beneath the surface. Current OSA parameterizations generally ignore the spectral dependence and ocean color. As climate models are advanced to include more sophisticated biological processes, a more accurate and spectrally resolved OSA parameterization is appropriate. We present our updated (and more GCM-friendly) OSA parameterization here. The parameterization consists of analytical fits to our look up table (LUT) scheme, which was developed for NASA's CERES surface and atmosphere radiation budget (SARB). The albedo is parameterized as a function of wind and ocean color (through chlorophyll, Chl, which is available from SeaWIFS/MODIS). OSA is separated into direct and diffuse components. The direct component also depends on the solar zenith angle. The spectral dependence is accounted by the refractive index (Fresnel reflection) and subsurface ocean optics in the function. Comparisons are given with broadband and spectral observations at the CERES Ocean Validation Experiment (COVE) ocean platform.