A general theory for equivalent barotropic thin jets

Abstract

The so-called thin-jet approximation, in which variations along the jet axis are assumed gradual in comparison with variations normal to the axis, allows the calculations of along- and cross-axis structures to be decoupled. The result is a nonlinear equation, with one lesser spatial dimension, governing the meandering of the jet. Here a new such "path equation' is constructed in the context of a one-layer, reduced-gravity model. After a brief comparison with previous path equations, analytical solutions of the new equation are explored, including solitons and other exact nonlinear wave forms. The presentation concludes with numerical experiments and a brief application to the Gulf Stream. -from Authors