GODAE is sponsored by
The CSS projects
Africa
P1 - Regional Ocean around Southern Africa (TOMOROSA)
The Agulhas Current system - Microwave SST and Absolute Geostrophic Velocities Domain
The focus of the nested model domain is the regional ocean around Southern Africa, approximately 0-60°E and 10-50°S.
Objectives
Advance the understanding of mesoscale dynamics and eddy evolving processes in the Agulhas Current system, the retroflection through integrated use of the ocean model HYCOM, satellite observations and in-situ measurements. Investigate the importance and impacts of applying advanced numerical schemes, improved model parameterization and data assimilation techniques.
Real time monitoring and prediction system, research.
Implementing HYCOM as one component of in a operational monitoring and forecasting system for the Southern African Ocean.
Customers:
Research, fisheries, oil industry, shipping (commercial and leisure)
Funding aspect:
This project is supported by the MohnSverdrup Center for Global Ocean Studies and Operational Oceanography, through a private donation from Trond Mohn C/O Frank Mohn AS, Bergen, and by the Department of Oceanography, University of Cape Town.
Downscaling strategy
TOMOROSA is forced at the boundaries by a basin scale HYCOM model of the Indian and Southern Ocean developed and operated by the Mohn Sverdrup Center at NERSC. The time resolution of the lateral boundary conditions is 6 hours, anticipating for ulterior addition of astronomical tides. The downscaling method is that of Browning and Kreiss (1982, 1986) with bilinear interpolation to the nested horizontal grid.
The monitoring and prediction system is driven by external inputs, i.e. atmospheric forcing fields. Further observational external information, such as sea level anomaly, sea surface temperature and in-situ measurements of temperature and salinity profiles, is merged with a coupled model system including an ocean general circulation model usingsophisticated data assimilation techniques. The products include short range (weekly) predictions of physical and biological variables as functions of space and time.
| Why does this project need large scale estimates? | The mesoscale variability in the Agulhas Current is forced by interactions with the basin scale Circulation in the Indian and Southern Ocean. Large scale estimates are applied as boundary conditions in a two model system, i.e. a parent basin scale model and a nested regional model. |
| Strategy for validation of boundary conditions | The incoming fluxes, kinetic energy and water mass properties are monitored in the nested model and compared to available observations. |
Project status
Project is in development phase, preliminary results have been presented at the "15 years of progress in radar altimetry" symposium in Venice (March 2006) [Backeberg et al., 2006].
References
Backeberg, B. C., J. A. Johannessen, L. Bertino, N. G. Winther, and K. A. Lisæter, The uses of satellite altimetry in model validation and variability studies for the Agulhas Current, in ESAs Publications Division (EPD), Special Publication SP614 on CD, European Space Agency (ESA), 2006, Proceedings paper for the 15 years of progress in Radar Altimetry symposium, available online.
(Last Updated: 17-01-2008)