Effects of a marine ridge to western boundary current in a three-dimensional source-sink flow model

A numerical experiment is made with a three-dimensional source-sink flow model in order to study effects of a marine ridge to the western boundary current. The model represents the Kuroshio current crossing the Izu Ridge which has a submarine narrow passage. It is indicated that most of the surface water of the western boundary current crosses the ridge through the narrow passage. A part of the surface water circulates around a warm eddy formed in an upstream region of the ridge. A water below the thermocline makes a long detour around the ridge and forms a subsurface northward current along the eastern slope of the ridge.