Katabatic wind in Antarctica: A modelling study.

In the Antarctic Continent cold air formed in the large interior Plateau drains down towards the coastline because of the terrain slope. Such a cold air layer formation is tills to the action of net radiative cooling at the lee surface covering most part of the interior of the Continent. A mesoscale numerical model has been adapted to he used to simulate katabatic wind episodes in the coastal and near coastal regions of the Antarctic Continent. Results are presented relatively to two different cases: the first is the simulation of an ideal katabatic flow development with zero synoptic wield initial conditions, and for two different sea-ice conditions: the second is the formation of the cold slab and katabatic wired forced by real initial conditions given by the ECMWF analysis, relative to two different austral summer days. Particular attention has been devoted to the set up of the initial and boundary conditions and to the proper values of the physical parameters, like the albedo of the surface and the soil scheme. The modeling results show that a correct choice of the values of physical parameters and tilt! introduction of the effective boundary between open ocean and ice covered sea surface influence the onset and the features of the katabatic flow. Those partially positive results encourages further studies, in particular in the direction of refining the grid resolution in ol der to better describe small scale features to be compared to experimental data.