Circulation and boundary layers in differentially heated rotating stratified fluid

Recent laboratory experiments with rotating stratified water in a cylinder have revealed many of the predictions of linearized, analytic theory. Earli er measurements of the velocity field generated in a cylinder by top heatin g compared well with theory. Large stratification clearly suppressed Ekman pumping so that the interior velocity field (primarily azimuthal) responded by satisfying no-slip top and bottom boundary conditions without the need for Ekman layers. This interior flow also occupied a boundary layer of grea ter thickness than the Ekman layer under some conditions. Theory and experi ments have now been conducted for sidewall heating. As before, experiment a nd theory agree well over some parameter ranges. But for some parameters, t he flow is unstable. The exact nature of the instability remains poorly und erstood. The size of one combination of both vertical and horizontal bounda ry layers is governed by the Rossby radius of deformation multiplied by the square root of the Prandtl number. Sidewall boundary layers and their scal es will be reviewed with the present results in mind. (C) 2000 Elsevier Sci ence B.V. All rights reserved.