AXISYMMETRICAL MAGNETOCONVECTION IN A TWISTED FIELD

The process of flux rope formation in a convecting cell is studied. Th e magnetic field has both a meridional and an azimuthal component, and so corresponds to a twisted field. Convection occurs in this cylindri cal cell because of heating from below, and is assumed to take an axis ymmetric form. Only the Boussinesq problem is studied here, but both t he kinematic and the dynamic regimes are considered. The two cases whe re the twisted field is due to (a) an imposed flux of vertical current and (b) an imposed flux of vertical vorticity are considered. Strongl y twisted ropes can be generated more easily in case (b) than in case (a). We show that convection can produce ropes twisted in the opposite direction from that of the initial field. We also find that solutions can be oscillatory even when linear theory predicts steady solutions.