EFFECTS OF PARTIAL MERIDIONAL BARRIERS ON THE ANTARCTIC CIRCUMPOLAR CURRENT WIND-DRIVEN BAROTROPIC MODEL

The structure and transport of the Antarctic Circumpolar Current are examined by means of a simple barotropic model. We investigate the effects of two partial meridional barriers, corresponding to the South American peninsula and the island arc to the east. The transport is given by the ratio of the pressure difference produced by wind stress to the resistance resulting from bottom friction. In the limiting case with no friction, the pressure difference is determined by the magnitude of the wind stress at the latitudes of the ends of the two meridional barriers, and the resistance is proportional to the difference between the Coriolis parameters at the same sites. The transport predicted by the model is reasonable as compared with the observed value. This suggests that the mechanism discussed in this paper can be applied to the real ocean. We also find the relationship between the transport and the topographic drag on the meridional barriers. The time change of the transport is determined by the drag on the meridional barriers, the bottom stress, and the rate at which momentum is supplied by wind stress. The transport lags wind stress by several days.