Ocean Predictions with ACCESS-S

Several versions of the Bureau of Meteorology’s seasonal forecast system POAMA (Predictive Ocean Atmosphere Model for Australia) have been developed over the past decade and the Bureau’s seasonal climate outlooks have become increasingly skilful and useful. However, POAMA has a relatively low resolution (T47 atmosphere) and is due to be replaced with a higher-resolution system (N216 atmosphere) which will be referred to as ACCESS-S (the seasonal prediction version of the Australian Community Climate and Earth-System Simulator). ACCESS-S, which is currently being developed, will be based on the UK Met Office Global Coupled model 2.0 (GC2) together with locally developed enhancements. ACCESS-S provides forecasts on intra-seasonal to seasonal timescales out to a lead time of 6 months. We will present an analysis of the mean state, variability and skill of the ocean forecasts at different timescales based on a preliminary hindcast set with a limited number of ensemble members for the period 1990-2012. The ocean model component of the GC2 model is the state-of-the-art NEMO model which has a 25 km horizontal resolution and 75 levels in the vertical.