Transport of a quasigeostrophic Antrctic circumpolar current

A conceptual model for the zonal transport of the ACC is presented and tested against numerical simulations. This model combines ideas from basin theories and channel theories of the ACC. Basin theories are essentially based on the effect of the wind stress curl (vorticity balance) whereas channel theories are based on the effect of the wind stress itself (momentum balance). The conceptual model fits the numerical results over a large range of parameters. For example, it explains the transport saturation observed in similar idealized numerical experiments. Assuming that topography blocks the circumpolar flow at depth, this saturation is explained by the presence of a strengthening Sverdrup-like recirculation driven by the wind stress curl. Experiments investigating the relative roles of the wind stress and wind stress curl show that the dynamics and transport of the ACC are strongly affected by both parameters. When the curl is set to zero, Sverdrup-like recirculation disappears and the transport increases significantly.