Evaluation of data sets used to force sea ice models in the Arctic Ocean

Abstract

Basin-scale sea ice models are often run uncoupled to either an atmosphere or ocean model to evaluate the sea ice model, to compare different models, and to test changes in physical parameterizations. Such simulations require that the boundary forcing be specified. The specification of atmospheric forcing associated with the surface heat and freshwater fluxes has been done in various sea ice simulations using climatology, numerical weather prediction analyses, or and satellite data. However, the errors in the boundary forcing may be so large that it is difficult to determine whether discrepancies between simulated and observed properties of sea ice should be attributed to deficiencies in the sea ice model or to the boundary forcing. To assess the errors in boundary forcing, we use data from the Surface Heat Budget of the Arctic Ocean (SHEBA) to evaluate various data sets that have been used to provide boundary forcing for sea ice models that are associated with the surface heat and freshwater fluxes. The impact of errors in these data sets on a sea ice model is assessed by using a single-column ice thickness distribution model, which is alternately forced with in situ measurements from SHEBA and output from large-scale analyses. Substantial discrepancies are found among the data sets. The response of the sea ice model to the different forcing data sets was considerable.