Numerical weather prediction in East Antarctica

The Australian Bureau of Meteorology's local area predictive scheme (LAPS) is being assessed as a tool for providing more accurate short term weather forecasts in and around the East Antarctic coast and surrounding Southern Ocean. Currently available global models provide only coarse resolution output which often fail to adequately capture the flow detail evident in the topographically forced planetary boundary layer. LAPS is a latitude-longitude grid point model using sigma coordinates in the vertical and employing data assimilation. Runs of the model at a resolution near 25 km have demonstrated a much improved definition of the surface flow, with further improvements evident with the physics tuned to better represent Antarctic conditions and modifications made to the initialisation and nesting fields to improve the representation of surface temperature in the sea-ice zone. Some results from the model are presented along with comparisons with both single station observational data and output from the Australian global model (GASP), which was used to provide the initial conditions and nesting fields.