Bénard Convection in the Presence of Vertically Varying Exchange Processes

Abstract

The Benard convection problem is examined using a geophysical model in which the eddy coefficients of viscosity and heat conductivity vary linearly with depth. For variations corresponding to measured coefficients, the temperature difference over the fluid layer necessary for thermal instability decreases by up to 40% of that needed when the coefficients remain constant. The first unstable mode is affected very little by the coefficient variation. The position of the lower oceanic boundary of a convective layer is discussed briefly.