Convective Instability in a Rapidly Rotating Viscoelastic Layer

The linear stability of a highly rotating horizontal viscoelastic fluid layer heated from below is studied in the Boussinesq approximation, when the fluid is governed by relations due to Oldroyd. The problem is solved by using singular perturbation methods. The effect of elasticity is shown to destabilize the layer, in general. However, the degree of destabilization depends crucially on the retardation time of the fluid as well as on the type of boundary under consideration. The reason for the destabilization is traced down to the inhibition of viscous dissipation by elasticity.