BAROTROPIC THIN JETS OVER ARBITRARY TOPOGRAPHY

An existing theory for thin jets on the beta plane is modified for app lications to arbitrary topography. While the resulting path equation b ears close resemblance to that for the beta plane, the fact that botto m topography, unlike the Coriolis parameter, can vary non-monotonicall y and in both horizontal directions leads to interesting effects, such as retroflection and jet trapping. Applications to a rectilinear ridg e and a circular seamount lead to analytical criteria predicting under what conditions a jet, of known upstream profile, will be deflected, retroflected or trapped. Finally, an application to an elliptical seam ount has possible implications for the ring current atop Georges Bank in the Gulf of Maine. (C) 1997 Elsevier Science B.V.