ON ISALLOBARIC EFFECT IN A QUASI-GEOSTROPHIC TOPOGRAPHIC-DRAG PROBLEM

Isallobaric effect of a slowly varying quasigeostrophic flow represented by propagating waves may give rise to a mean steady topographic drag component which turns out to be the principal one when viscous effects are negligibly small. This drag component decreases, in contrast to the quasigeostrophic component, when statistical properties of the topography become isotropic. When the phase velocity of the incident wave is much larger (smaller) than the phase speed of Rossby waves, the isallobaric drag becomes independent (dependent) on the sign of that velocity. © 1991, Taylor & Francis Group, LLC. All rights reserved.