Magnetic field generation by baroclinic waves

Abstract

The general theory of the linear instabilities created by density differences in a rotating magnetic system is considered, and is applied to a plane layer stably stratified but with a slight superimposed horizontal density gradient that can give rise to baroclinic waves, modified by the presence of a horizontal co-rotating magnetic field parallel to the thermal wind. It is shown that, unlike the conceptually similar models of Gilman, regeneration of this magnetic field by the waves in the face of a slight resistivity of the medium can only occur within the critical layer, i. e. the diffusive layer surrounding the level at which wave and wind speeds are equal. Conditions for such self-sustaining dynamo action are given.