Thermal convection in a rotating fluid: effects due to bottom topography

Abstract

A study has been made of the effects of non-axisymmetric bottom topography in a differentially heated, rotating fluid annulus. In the absence of free baroclinic waves the disturbance produced by topography of vertical dimensions typically much less than the depth of the fluid and horizontal dimensions comparable to the gap width is steady and confined to the lower part of the fluid. The maximum amplitude of this disturbance depends on the angular speed of rotation of the apparatus and varies with height, being very small above the level where the basic azimuthal flow reverses. The flow pattern shows a closed circulation displaced relative to the topography in the downstream direction. In the presence of free baroclinic waves the topographic wave extends throughout the whole depth of the fluid. Determinations of the amplitude and phase of the various azimuthal Fourier components present show that the topographically forced components exchange energy with the free components as they drift relative to the topography.