Ventilation of Eastern Subtropical Gyres

Abstract

A simple mechanism for the generation of flow in the eastern region of the oceans is presented. It is shown that even a small amount of upwelling-favorable wind stress parallel to the boundary makes the subducted geostrophic contours veer into the eastern boundary. This sweep toward the wall ventilates the top few hundred meters of the eastern subtropical gyre. The latitudinal extent of the eastern ventilation is calculated. Along a meridional boundary the subsurface flow is eastward and appears to provide the mass source for the poleward undercurrents observed at the eastern boundary of the ocean.