Finite-beta and curvature drift effects on drift waves near the plasmapause

Abstract

The linear stability of finite-β drift waves, near the plasmapause of the earth, is analysed for the case in which the magnetic field is non-uniform in two dimensions. The coupling of the drift wave to the oscillation of the magnetic field, due to non-zero β, is found to be destabilizing. The spatial structure of the unstable mode is found to be governed by the ‘curvature’ scale length of the equilibrium magnetic field.