ON COASTAL JETS AND UPWELLING IN BOUNDED BASINS.

Abstract

THE RELATIONSHIP BETWEEN COASTAL UPWELLING AND COASTAL LONG-SHORE CURRENTS IS STUDIED IN A SIMPLE MODEL OF A CONTINUOUSLY STRATIFIED FLUID IN A CLOSED BASIN OF THE F-PLANE.IT IS SHOWN THAT THE COASTAL LONG-SHORE CURRENT AT ANY POINT ON THE BASIN'S PERIMETER IS DETERMINED PRIMARILY BY THE COMPONENTS OF THE LONG-SHORE STRESS WITH THE LARGEST LONG-SHORE SCALES, IN PARTICULAR FROM THE PERIMETER AVERAGE OF THE LONG-SHORE STRESS.IN ADDITION, THE DEPTH STRUCTURE OF UPWELLING ITSELF IS SHOWN TO BE DEPENDENT ON THE LONG-SHORE SCALE.IT IS CONCLUDED THAT THE RELATIONSHIP BETWEEN UPWELLING AND LONG-SHORE CURRENTS IS NON-LOCAL, THAT MASS BALANCE IS NOT ACHIEVED LOCALLY IN PLANES NORMAL TO THE COAST, AND THAT THE RELATIONSHIP BETWEEN ONSHORE FLOWS AND LONG-SHORE CURRENTS IS SCALE-DEPENDENT.AN INTRINSIC LONGSHORE LENGTH SCALE IS FOUND SEPARATING TWO REGIMES OF FLOW WITH DISTINCTLY DIFFERENT RELATIONS BETWEEN THE WIND STRESS, ONSHORE, AND LONG-SHORE FLOWS.SINCE BOTH REGIMES ARE PRESENT SIMULTANEOUSLY FOR A WIND STRESS CONTAINING A VARIETY OF LONG-SHORE SCALES, THE DETERMINATION OF THE LONGSHORE STRUCTURE OF THE WIND STRESS IS ESSENTIAL TO AN UNDERSTANDING OF THE LOCAL OCEANIC UPWELLING AND LONG-SHORE CURRENT STRUCTURE.(A).