STRUCTURE OF AN INERTIAL DEEP WESTERN BOUNDARY CURRENT

An inertial model of the deep western boundary current (DWBC) is prese nted where the cross-stream distribution of potential vorticity varies in a realistic fashion. The case of uniform potential vorticity, whic h has been solved earlier, is included for comparison. The potential v orticity distribution used in the model is obtained from a hydrographi c density section across the North Atlantic DWBC. The model solutions using this distribution differ significantly from the uniform potentia l vorticity case. Most notably the current is wider and weaker with su bstantially reduced relative vorticity, more indicative of observed DW BCs. The addition of an exponential continental slope leads to a furth er constraint on the existence of the current. Finally, it is demonstr ated how a topographic ridge can partially block the DWBC and give ris e to recirculation of the deepest water, reminiscent of the deep flow near the Southeast Newfoundland Rise in the North Atlantic.