The Bureau of Meteorology established operational ocean forecasting in August 2007 through the Ocean Model, Analysis and Prediction System (OceanMAPS). OceanMAPS was developed through the BLUElink project an Australian government partnership between the Australian Bureau of Meteorology, CSIRO and the Royal Australian Navy. A major upgrade to this system OceanMAPS version 2 (OceanMAPSv2) was implemented operationally in December 2011 developed through a follow-on BLUElink-2 project. The new system is based on the latest GFDL Modular Ocean Model version 4 and the BLUElink Ocean Data Assimilation System. The area of high horizontal resolution, 0.1°×0.1°, has remained confined to the Australian region, 90E-180E, 7S-75N however, the vertical resolution in the surface layer was refined to 5 m. OceanMAPSv2 shows approximately a 30% reduction in root mean square error over OceanMAPS for both sea surface temperature and sea surface height anomaly. In particular, the root mean square error for sea surface height anomaly shows that the worst forecasts from OceanMAPSv2 have lower error than the best forecasts from OceanMAPS. A major contributor to the improved performance is the implementation of a new initialisation scheme that more efficiently introduces the BODAS analyses into the ocean model. OceanMAPSv2 has also introduced a daily forecast schedule compared with the twice per week schedule of OceanMAPS. A new four-cycle design was introduced where four independent forecast cycles each time-lagged by one day over four consecutive days are each repeated on a four day period. This system is referred to as a multi-cycle lagged ensemble, as it is demonstrated to have higher cycle-to-cycle independence compared with a traditional time-lagged ensemble. OceanMAPSv2 therefore introduces a range of ensemble diagnostics for each ocean forecast.
Collection(s) and Series: CAWCR technical report- No. 52
Format: Digital (Free), Hard copy