A 20-year hindcast of Arctic sea ice using assimilated sea ice motion

Basin-scalea ice dynam ic models approximate the sea ice as a continuous viscous fluid. This assumption is based on a limited inventory of observations of sea ice at the time of model development, but is sufficient to simulate monthly mean sea ice drift. Satellite-derived observations have greatly increased the temporal and spatial coverage of sea ice motion data, showing the large-scale sea ice drift behaves in a manner consistent with its discrete floe and plate nature. This behavior has not been well-produced in sea ice dynamic models of the kind typically included in coupled climate models. Here, a 20-year hindcast of Arctic sea ice conditions is performed using optimal interpolation to assimilate observed ice motion data into the calculated solution. The additional constraint on sea ice motion reveals the model’s sensitivity to internal parameterizations, and suggests further work is necessary to improve numerical parameterizations of physical sea ice processes.