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Abstract

As a supplement to an earlier paper on a coupled sea—ice — oceanic mixed-layer [SI — OML] model for the Southern
Ocean (Stössel et al.‚ 1990), the atmospheric forcing in this
investigation is changed from monthly (climatological) data to
daily (instantaneous) values. These data are derived from global
analyses from the European Center for Medium Range Weather
Forecasts (ECMWF). With these computations applied as surface
forcing, results similar to the earlier ones are achieved.
Adjustments of the SI-model parameters and/or the coefficients of
the bulk formulas can be avoided when the forcing is raised to its
originally assigned level, using an appropriate Prandtl—layer
parameterization. With this extension, the model results are well
comparable with observations based on operationally produced ice
charts.
A further rise of the atmospheric forcing to the geostrophic
level by means of coupling a one—dimensional atmospheric
boundary—layer [ABL] model to the SI — OML model, reduces the
dependency of the results on the (climatologically) prescribed
boundary conditions of the operational numerical weather-
prediction [NWP] model. The simulations with this extension,
however, appear to be reasonable only when the surface wind
pattern is applied, the roughness length over ice and water is
increased, and the stability of the ABL over ice is generally reduced.