Oceanography SeminarApril 24, 3:00pm - 4:15pm
Mānoa Campus, Marine Sciences Building, MSB 100
CSIRO Marine and Atmospheric Research
“Ocean Reanalyses and Forecasting in Australia”
Abstract: Over the last ten years, an eddy-resolving ocean forecast and reanalysis system has been developed in Australia, under a partnership called Bluelink (between CSIRO, the Bureau of Meteorology, and the Australian Navy). The system uses a simple ensemble-based data assimilation system (Ensemble Optimal Interpolation) to combine observations from satellite altimetry, satellite SST, Argo, XBT, and TAO data with an eddy-resolving ocean model. A description and evaluation of the most recently-completed reanalysis will be presented. The latest 20-year reanalysis fits observations of sea-level, temperature, salinity, and velocities from surface drifting buoys in the Australian region to within 8 cm, 0.7 degrees, 0.16 psu, and 20 cm/s respectively. Owing to recent improvements in the model, the initialisation approach, and careful pre-processing of observations, the most recent reanalysis outperforms previous reanalyses - with a closer fit to observations, but with less artificial adjustment via assimilation. The details of these improvements will be described.
Other developments under Bluelink include a relocatable ocean-atmosphere-wave system that allows a non-expert user to initiate and execute a forecast in near-tea-time. This relocatable system includes assimilation of available observations and facilitates forecasts of (almost) any region around the world down to scales of a few kilometres. An overview of the relocatable system, together with examples, will be described - including the ³dirty laundry² of developing a robust forecasting capability for non-expert users.
Oceanography, Mānoa Campus