Applications of SHEBA/FIRE data to evaluation of snow/ice albedo parameterizations

Climate models use a wide variety of parameterizations for surface albedos of the ice-covered ocean. These range from simple broadband albedo paramete rizations that distinguish among snow-covered and bare ice to more sophisti cated parameterizations that include dependence on ice and snow depth, sola r zenith angle, and spectral resolution. Several sophisticated parameteriza tions have also been developed for thermodynamic sea ice models that additi onally include dependence on ice and snow age, and melt pond characteristic s. Observations obtained in the Arctic Ocean during 1997-1998 in conjunctio n with the Surface Heat Budget of the Arctic Ocean (SHEBA) and FIRE Arctic Clouds Experiment provide a unique data set against which to evaluate param eterizations of sea ice surface albedo. We apply eight different surface al bedo parameterizations to the SHEBA/FIRE data set and evaluate the paramete rized albedos against the observed albedos. Results show that these paramet erizations yield very different representations of the annual cycle of sea ice albedo. The importance of details and functional relationships of the a lbedo parameterizations is assessed by incorporating into a single-column s ea ice model two different albedo parameterizations, one complex and one si mple, that have the same annually averaged surface albedo. The baseline sea ice characteristics and strength of the ice-albedo feedback are compared f or the simulations of the different surface albedos.