Vertical and Lateral Mixing Processes Deduced from the Mediterranean Water Signature in the North Atlantic

Abstract

The conservation equations of heat, salt, and mass are combined in such a way that a simple relation is found between the known volume flux of Mediterranean Water entering the North Atlantic Ocean and the effects of lateral and vertical mixing processes. The method is a form of inverse method in which the only unknowns are the vertical and lateral diffusivities. For each isohaline contour on each neutral density surface the authors develop one equation in two unknowns, arguing that other terms that cannot be evaluated are small. By considering several such isohaline contours, the method becomes overdetermined for each density layer, and results are found for both the vertical and lateral diffusivity that vary smoothly in the vertical direction, giving some confidence in the method.