Separation of a midlevel density current from the bottom of a continental slope

The high-salinity water flowing out of the Mediterranean Sea descends to mi d depths in the density-stratified ocean, continues as a narrow jet along t he Iberian continental slope, and intermittently detaches large-scale eddie s (called "Meddies"). This process is important because it maintains the re latively high mean salinity of a major water mass (the "Mediterranean Inter mediate Water") in the North Atlantic. Our simplified model of this jet con sists of a moving layer with intermediate density rho(2) sandwiched between motionless layers of density rho(1) < rho(2) and rho(3) > rho(2). The insh ore (anticyclonic) portion of the midlevel jet (in the "rho(2)-water") rest s on an inclined bottom (the continental slope), whereas the (cyclonic) off shore portion rests on the density interface of the stagnant deep (rho(3)) layer. An inviscid, steady, and finite-amplitude longwave theory is used to show that if the cross-stream topographic slope increases gradually in the downstream direction, then the "rho(2)-jet" is deflected off the bottom sl ope and onto the upper density interface of the rho(3) layer. The computed magnitude of this separation effect is such as to produce an essentially fr ee jet which is removed from the stabilizing influence of the continental t opography. It is therefore conjectured that time-dependent effects (barocli nic instability) mill produce further amplification, causing an eddy to det ach seaward from the branch of the jet remaining on the slope.