The Bluelink Ocean Forecast System

David Griffin, Peter R Oke, Andreas Schiller

CSIRO Marine and Atmospheric Research, GPO Box 1538, Hobart, Tas 7001,
Australia

Bluelink is an Australian partnership between CSIRO, the Commonwealth Bureau of Meteorology and the Royal Australian Navy. The main objective of Bluelink is to develop an ocean forecast system for the mesoscale circulation around Australia. To this end, the Ocean Forecasting Australia Model (OFAM), a global configuration of MOM4.0 with 0.1 degree resolution in the Australasian region (90E-180E, and 75S-16N), has been configured. The Bluelink Ocean Data Assimilation System (BODAS) is an ensemble optimal interpolation system that assimilates observations of sea level, temperature and salinity into OFAM. A preliminary assessment of the system's performance has been undertaken through the Bluelink ReANalysis (BRAN) experiment that covers the period 1992-2004 and assimilates altimetric sealevel (ERS, Envisat, T/P, Jason and GFO) and
temperature and salinity profiles (Argo, WOCE, TAO and other).

Comparisons between BRAN fields and withheld observations demonstrate that the system can produce realistic results. Through a series of experiments, we have endeavoured to determine i) whether the present ocean observing system is sufficiently comprehensive to adequately constrain our ocean model using our assimilation method, and ii) the relative importance of the surface and sub-surface observations. The first operational forecasts using the Bluelink system are scheduled for 2006.