The destruction of lenses and generation of wodons

Since midocean eddies migrate westward, they eventually reach the western boundaries. It is, therefore, of interest to find out what happens after the eddies collide with the walls. An isopycnic, two-layer, primitive equation model on a beta plane and a simple analytical model on an f plane are constructed to investigate the meridional migration of an oceanic eddy along a western wall. On a beta plane, three factors determine the eddy's migration along a western meridional wall. First, the image effect pushes an anticyclonic (cyclonic) eddy northward (southward). Second, the beta force (resulting from the larger Coriolis force on the northern side of the eddy) pulls an anticyclonic (cyclonic) eddy southward (northward). Third, after an anticyclonic (cyclonic) eddy collides with the wall, parts of the anticyclonic eddy's interior fluid leak out southward (northward) along the wall forming a thin jet. In an analogy to a rocket, this jet pushes the eddy northward (southward). Our aim is to investigate in which direction the eddy ultimately migrates along the wall (i.e., to determine which of the above three processes dominates).