A SIMPLE-MODEL FOR A BUOYANCY-DRIVEN DYNAMO IN ACCRETION DISCS

A model for the magnetic dynamo process in accretion discs is proposed that does not involve underlying turbulent motions. The key ingredien t of the model is the magnetic buoyancy. Combined with Coriolis twist, the buoyant motions result in a backcoupling between azimuthal and ra dial components of the field. It is shown that for reasonable values o f the free parameters of the model all three components of the magneti c field reach a stable saturation state consistent with the basic assu mptions underlying the model.