Ocean Science Southern Ocean overturning across streamlines in an eddying simulation of the Antarctic Circumpolar Current

• Main Authors: A. M. Treguier, M. H. Engl, S. R. Rintoul, G. Madec, J. Le Sommer, J. -m. Molines
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2007
• Subjects: Antarctic; Southern Ocean; The Antarctic; Antarc*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.685.5648; http://web.science.unsw.edu.au/%7Ematthew/os-3-491-2007.pdf

Abstract. An eddying global model is used to study the char-acteristics of the Antarctic Circumpolar Current (ACC) in a streamline-following framework. Previous model-based es-timates of the meridional circulation were calculated using zonal averages: this method leads to a counter-intuitive pole-ward circulation of the less dense waters, and underestimates the eddy effects. We show that on the contrary, the upper ocean circulation across streamlines agrees with the theoret-ical view: an equatorward mean flow partially cancelled by a poleward eddy mass flux. Two model simulations, in which the buoyancy forcing above the ACC changes from positive to negative, suggest that the relationship between the resid-ual meridional circulation and the surface buoyancy flux is not as straightforward as assumed by the simplest theoret-ical models: the sign of the residual circulation cannot be