HYDROMAGNETIC CONVECTIVE INSTABILITY IN A ROTATING VISCOELASTIC LAYER HEATED FROM BELOW.

The linear stability of a highly rotating viscoelastic fluid layer heated from below and lying in a uniform magnetic field is studied in the Boussinesq approximation. A singular perturbation method is successfully employed to identify the preferred mode of convection for all magnitudes and directions of the magnetic field for a variety of surface conditions. The analysis shows that the magnetic field inhibits the dynamic influence of the boundaries on the critical mode of convection but introduces the dependence of the marginal state on the electrical and magnetic properties of the boundaries.