The Australian community climate and earth system simulator global and regional ensemble prediction scheme

Abstract

We report on progress in the development of the Australian Community Climate and Earth Systems Simulator Global and Regional Ensemble numerical weather Prediction Scheme at the Australian Bureau of Meteorology. Based on the UK Met Office ensemble, AGREPS implements an Ensemble Transform Kalman Filter to generate independent initial perturbations as fast growing disturbances with structures and growth rates typical of the analysis errors. This method allows information about the fast growing errors to be incorporated into the initial perturbations for the forecast. An ensemble of model states is propagated, using the numerical weather prediction system and observing network at the Australian Bureau of Meteorology, from which covariances are constructed then localized and inflated to minimize the effect of small sample size. References

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