Abstract
The model developed by Pedlosky and Young is used to investigate the feedback of a Rhines–Young pool on a ventilated thermocline. It is found that the potential vorticity gradient in a ventilated layer is reduced due to the nonlinear coupling with a deep Rhines–Young pool. Physically, this occurs because part of the Sverdrup transport is carried by the deep pool. As a result the subduction velocity, and in turn, the potential vorticity gradient of the subducted water, is decreased.