| Volumes and Issues Contents of Issue 4 |
www.ocean-sci-discuss.net/4/653/2007/
© Author(s) 2007. This work is licensed
under a Creative Commons License.
Southern Ocean overturning across streamlines in an eddying simulation of the Antarctic Circumpolar Current
1Laboratoire de Physique de Oceans, CNRS-IFREMER-UBO, Plouzané, France
2University of New South Wales, Sydney, Australia
3CSIRO Wealth from Oceans National Research Flagship and Antarctic Climate and Ecosystems CRC, Hobart, Australia
4Laboratoire d'Océanographie et du Climat: Experimentations et Approches Numériques, Pierre and Marie Curie University, Paris, France
5Laboratoire des Ecoulements Geophysiques et Industriels, Joseph Fourier University, Grenoble, France
Abstract. An eddying global model is used to study the characteristics of the Antarctic Circumpolar Current (ACC) in a streamline-following framework. In the upper layers, the meridional circulation across streamlines agrees with the theoretical view: an equatorward mean flow partially cancelled by a poleward eddy mass flux. The same calculation in a zonal average gives a completely different view and underestimates the eddy effects. Two model simulations, in which the buoyancy forcing above the ACC changes from positive to negative, suggest that the relationship between the residual meridional circulation and the surface buoyancy flux is not as straightforward as assumed by some recent theoretical studies: even the sign of the residual circulation cannot be inferred from the buoyancy forcing. Heat and salt transports by the time-mean flow are important even in the streamline framework. Streamline-averaged, two-dimensional models cannot account quantitatively for the complex three-dimensional structure of the ACC. Heat and salt are balanced in the ACC, the model drift being small, but the nonlinearity of the equation of state cannot be ignored in the density balance.
Discussion Paper (PDF, 1025 KB) Interactive Discussion (Closed, 6 Comments) Final Revised Paper (OS)
Citation: Treguier, A. M., England, M., Rintoul, S. R., Madec, G., Le Sommer, J., and Molines, J.-M.: Southern Ocean overturning across streamlines in an eddying simulation of the Antarctic Circumpolar Current, Ocean Sci. Discuss., 4, 653-698, 2007. Bibtex EndNote Reference Manager
