Transport and storage of magnetic field by overshooting turbulent compressible convection

We present the results of a series of numerical experiments that investigat e the transport of magnetic fields by turbulent penetrative compressible co nvection. We find that magnetic flux is preferentially transported downward out of a turbulent convecting region and stored in a stably stratified reg ion below. This pumping mechanism is believed to be a crucial component for the operation of a large-scale solar interface dynamo since it may be resp onsible for the transport of flux from the solar convection zone to the sta ble overshoot region. The high-resolution three-dimensional simulations sho w that efficient pumping occurs as a result of the action of strong coheren t downflowing plumes. The properties of the transport are evaluated as a fu nction of magnetic field strength, rotation rate, supercriticality, stiffne ss of the interface, and configuration. The turbulent pumping of magnetic f lux is remarkably robust and more efficient than its laminar counterpart. T he turbulent convection naturally amplifies magnetic energy from any existi ng mean field. The transport of flux from the convection zone removes the s ource for this local amplification there, and thus the peak magnetic energy also comes to reside in the stable region. This is important for an effect ive interface dynamo.