Representation of Sea Ice Processes in State of the Art Earth System Models.

Abstract:

The majority of Earth System Models now include thermodynamic-dynamic sea ice models with a subgridscale representation of ice thickness. The current sea ice component of the Community Earth System Model is the Los Alamos sea ice model (CICE) version 5. This new version of the model includes prognostic salinity in the vertical thermodynamic calculation as well as a representation of melt pond drainage through the sea ice. The CICE5 also includes a melt pond parameterization that takes into account the deformed and non-deformed ice within a model grid cell. Snow on sea ice processes allow for an evolving effective snow grain radius as a function of temperature, which is used in the shortwave radiative transfer and surface albedo calculation. I will discuss the results from coupled climate model sensitivity simulations that consider the subgridscale representations of some of these processes. This will include analysis of mean state and feedbacks in both the Arctic and Antarctic. Additional discussion will be provided on how we have used observations to guide these efforts.