ABSTRACT

This chapter considers magnetostrophic waves in a horizontal thin plane layer of a perfectly conducting fluid, which is stratified according to gravitation, permeated by a variable horizonal magnetic field and rotating rigidly around an inclined axis. It shows that unstable magnetostrophic waves are capable of inducing an electromotive force parallel to the horizontal magnetic field. The stability of magnetostrophic waves is considered in a horizontal thin plane layer of a perfectly conducting fluid, which is stratified according to gravitation and permeated by a variable toroidal magnetic field. The layer rotates rigidly around an axis inclined to the horizontal plane. Dynamo theory describes how a magnetic field is generated by electric currents which are induced by motions in an electrically conducting fluid. Two processes are most important, differential rotation and helical flows. The linear treatment presented excludes the determination of the strength of the induction effect of the magnetic buoyancy instability.