Frictionally modified rotating hydraulic channel exchange and ocean outflows

Abstract

Laboratory experiments of two-layer exchange through channels of circular and half-circular cross section are described. Simple theoretical limits on exchange for the circular channels are obtained from models involving either friction or rotating hydraulic control alone. Ekman and Stewartson layers are appended to the rotating hydraulic control model in a simple theory for frictionally modified rotating control. In theory and experiment, rotation and friction together exert a stronger constraint on the exchange than they do separately. Secondary cross-channel circulations were found in the rotating experiments. These secondary circulations further reduce exchange by efficiently moving fluid that is spun down at the boundaries and interface into the interior. -from Authors