PREDICTIVE CONSEQUENCES OF CERTAIN PHYSICAL INCONSISTENCIES IN THE GEOSTROPHIC BAROTROPIC MODEL

Abstract

The physical inconsistency of geostrophic flow and small surface pressure tendencies is discussed. The frequently disastrous consequences in conventional geostrophic barotropic predictions are numerically identified by comparisons with experimental ?semi-geostrophic? barotropic predictions from which the inconsistency has been removed. Effects of the inconsistency of the geostrophic wind field with the equations of motion are also quantitatively isolated by comparisons of semi-geostrophic predictions with predictions made with wind fields which satisfy the balance equation. It is concluded that the principal fault of the conventional geostrophic approximation lies in the violation of the continuity equation. Its lack of the dynamic effects expressed in the equations of motion seems also significant, but is less important.