Introduction of variable drag coefficients into sea-ice models

Abstract

In order to consider the effect of different ice conditions on the momentum exchange between atmosphere and ocean, a parameterization for variable drag coefficients is introduced. A square dependence on ice concentration is combined with a linear dependence on deformation energy to account for the influence of floe edges as well as for roughness elements in regions with a more compact ice cover. The approach is not regionally specified and is applied over the whole model region. Empirical parameters are optimized via comparison with observed buoy-drift data.