Evaluating a regional climate model's ability to simulate the climate of the South-east coast of Australia

Abstract

The Weather Research and Forecast (WRF) model was run over South-east Australia from 1985 through 2008. The model used the following physics schemes: WRF Single Moment 5-class microphysics scheme; Rapid Radiative Transfer Model longwave radiation scheme; Dudhia shortwave radiation scheme; Monin-Obukhov surface layer similarity; Noah land-surface scheme; Yonsei University boundary layer scheme and Kain-Fritsch cumulus physics scheme. The model simulation uses boundary conditions from the NCEP/NCAR reanalysis with an outer 50km resolution nest and an inner 10km resolution nest. Both nests used 30 vertical levels. In order to assess WRF's potential for use in investigating the current and future climate, the simulation is evaluated against gridded surface temperature and precipitation observations created as part of the Australian Water Availability Project (AWAP). The WRF simulation is found to reproduce the climate of the south-east Australian coast reasonably well. WRF was able to improve on the climate produced by the NCEP/NCAR reanalysis (NNRP) which provided the boundary conditions for the WRF simulation. Investigation of the time series of precipitation anomalies show that WRF is able to capture the recent drought in the SE Australia. While the overall time series captured the drought well, the spatial patterns associated with the anomalies produced by WRF differed from those found in the AWAP dataset. Further work will investigate the reasons for these spatial differences as well as WRF's performance at shorter time scales. © 2010 IOP Publishing Ltd.