Why There is an Intense Eastward Current in the North Atlantic but not in the South Atlantic

Abstract

It is suggested that baroclinic currents may he expected to he sharper where deeper water or a decreasing Coriolis parameter lies in the direction of the Coriolis force. This is the case for the Gulf Stream between Hatteras and the Grand Banks. The suggested mechanism is that, in this case, Rossby waves propagating away must carry momentum up-gradient into the mean current. In the South Atlantic, they may carry momentum down-gradient, diffusing the mean flow. Abstract It is suggested that baroclinic currents may he expected to he sharper where deeper water or a decreasing Coriolis parameter lies in the direction of the Coriolis force. This is the case for the Gulf Stream between Hatteras and the Grand Banks. The suggested mechanism is that, in this case, Rossby waves propagating away must carry momentum up-gradient into the mean current. In the South Atlantic, they may carry momentum down-gradient, diffusing the mean flow.