THE INFLUENCE OF LAYER OUTCROPPING ON THE SEPARATION OF BOUNDARY CURRENTS .2. THE WIND-DRIVEN AND BUOYANCY-DRIVEN EXPERIMENTS

It is shown that the main characteristic of the Parsons western bounda ry current separation mechanism, namely a separation south of the zero wind stress curl line (ZWCL), is no longer present when diabatic effe cts are included through the addition of a mixed layer to the model st ructure. When diabatic processes are taken into account, the separatio n is associated with the outcropping of interior layers into the mixed layer where the horizontal density gradient is a maximum. The mainten ance of this maximum results from a balance between potential vorticit y conservation and diabatic processes. In spite of wide variations in either forcing functions or parameters, the how patterns of the therma lly forced experiments described herein remain very similar from one e xperiment to the other, with a separation latitude located at the ZWCL . It is only when salinity is allowed to vary significantly in space t hat one observes a significant move in the jet separation latitude.