Solitary Alfvén waves in inhomogeneous streaming plasma

Abstract

Large-amplitude Alfvén waves, propagating along the magnetic field in an inhomogeneous plasma with non-uniform streaming, are shown to be governed by the DNLS equation modified by the inhomogeneity and the streaming. For weak but arbitrary inhomogeneity this modified DNLS leads to accelerated solitary Alfvén waves. The acceleration is modified further owing to streaming. For certain values of the plasma β, streaming can change the accelerating solitons into decelerating solitons, and vice versa.