The Generation of Salinity Finestructure by Vertical Diffusion

Abstract

The nonlinear differential equation for the vertical diffusion of salt (or heat) has initially unstable solutions under conditions of high gravitational stability. These solutions stabilize as they approach alternating layers of high and low salinity gradient. A numerically computed example of this phenomenon resembles salinity finestructure observed in the Hudson Estuary. However, similar computations may result in the generation of mathematically artificial finestructure if the diffusion coefficient is not adequately smoothed or if unrealistic initial conditions are used.