Effects of variations in eddy diffusivity on property distributions in the oceans

Abstract

The hypothesis that variations in eddy diffusivity may be responsible for some of the observed distributions of oceanic scalars is explored. A gradient in eddy diffusivity affects property distributions much as would an additional velocity field from regions of high to low eddy diffusivity. In support of such an interpretation, the cross-isopycnal distribution of density is compared with an eddy diffusivity prescribed by the combination of boundary mixing and isopycnal exchange. Since the surface area available for boundary mixing varies with depth, similar variations are reflected in property distributions. For isopycnal distributions, an eddy diffusivity field inferred from the eddy potential energy field description of Dantzler (1977) is compared with the salinity distribution from the Mediterranean Outflow.