Hobart

Seminar abstract

Thursday 24 May 2007, 11.30 am
CSIRO Auditorium, Hobart

Matt Martin
UK Met Office

Open Ocean forecasting at the UK Met Office

The Forecasting Ocean Assimilation Model (FOAM) system produces operational short-range forecasts of the deep ocean every day. It assimilates in situ and satellite sea surface temperature data, in situ temperature and salinity profile data, and along-track altimeter sea level anomaly (SLA) data into several nested models of varying resolution. These are forced by six-hourly surface fluxes from the Met Office NWP system. An overview of the FOAM system will be presented, together with a description of some recent developments in two areas: improving the assimilation of altimeter data; assimilating ocean colour data into a coupled physical-biological version of the system.

Altimetry does not give an absolute height displacement, but rather it provides the displacement relative to a 7 year annual mean (1992-8). Using altimetry data can provide information on the ocean variability and on the seasonal cycle but not on the mean state. The scheme used to assimilate it however requires a mean dynamic topography (MDT) from some other source. Using different MDTs will result in differing corrections to the model's mean state. If the MDT is of high quality and is compatible with the model, these corrections can be advantageous, but conflicts between the model mean state and the MDT used can occur. The results of investigations into which MDT to use will be presented, together with a description of work on using the data assimilation scheme to correct for biases in the MDT.

The FOAM physical model has been coupled to the Hadley Centre Ocean Carbon Cycle (HadOCC) model which is a simple Nutrient-Phytoplankton-Zooplankton-Detritus model with a variable carbon:chlorophyll ratio. The ecosystem model uses nitrogen as its currency but also calculates carbon flows through the ecosystem. A scheme has been developed which enables assimilation of chlorophyll data derived from satellite ocean colour observations into the biogeochemical component of the coupled model. Integrations of the coupled FOAM-HadOCC system with assimilation of SeaWiFS chlorophyll data have been performed. The results from these integrations will be presented, with validation and assessment of the impact of the assimilation.

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Location:
CSIRO = Marine Laboratories Auditorium, Castray Esplanade, Hobart

For further information, or to schedule a seminar, contact:
To schedule a seminar, contact:
Karen Wild-Allen, (Oceanographic seminars) CSIRO Marine and Atmospheric Research (03) 6232 5010
Thomas Kunz, (Biological seminars) CSIRO Marine and Atmospheric Research
(03) 6232 5076
Annabel Ozimec (seminar administrator) CSIRO Marine and Atmospheric Research (03) 6232 5462
Sandra Zicus, Antarctic Climate and Ecosystems CRC (03) 6226 7888
Margaret Hazelwood, Institute of Antarctic and Southern Ocean Studies (IASOS) University of Tasmania (03) 6226 2971

Last updated 1/05/07