Eigen modes of a hot plasma discontinuity in magnetosphere

Abstract

It is shown that the surface with finite width between two regions of a plasma medium having different Alfven velocity can sustain a discrete set of hydromagnetic waves. One set of eigen values depends upon β (ratio of the kinetic pressure to the magnetic pressure) value of the "surface" region and is weakly dispersive. The other set is similar to the familiar fast mode and is controlled by the width of the hot surface. The latter mode, therefore, has a much higher frequency than the weakly dispersive mode.