An Analytic Model of the Agulhas Current as a Western Boundary Current with Linearly Varying Viscosity

Abstract

A recent current profile across the Agulhas Current shows a region of strong current shear near the continental slope and a relatively gentle exponential decay of the current offshore. If the standard Munk solution is used to fit the current profile, it can account for only 76% of the variance in the data. In an attempt to provide a better fit, the problem of a western boundary current with a linearly increasing viscosity coefficient is solved analytically. It is found that the new solution can explain 97.3% of the variance in the data. The addition of a constant viscosity inshore layer produces a further significant improvement, the final solution explaining 98.2% of the total variance.