On intermediate models for stratified flow

Abstract

Intermediate models contain physics between that in the primitive equations and that in the quasigeostrophic equations. The specific objective here is to investigate the absolute and relative accuracy of several intermediate models for stratified flow by a comparison of numerical finite-difference solutions with those of the primitive equations (PE) and with those of the quasigeostrophic (QG) equations. The numerical experiments involve initial-value problems for the time-dependent development of an unstable baroclinic jet on an f plane in a doubly periodic domain with flat bottom. Although the geometry is idealized, the problem is set up so that the dynamics should be similar to that of the baroclinic jet observed off the northern California coast in the Coastal Transition Zone (CTZ) field program. -from Authors