Alfvén‐Fast Wave Coupling in a 2D Nonuniform Medium

Abstract

Abstract A 2D Cartesian simulation is presented and used to solve the ideal, low‐beta, linear magnetohydrodynamics equations. A simulation is used to investigate the propagation of Alfvén waves through inhomogeneities in Alfvén speed and density. In particular, the loss of Alfvén wave energy through coupling to the fast wave, and also the form of the Alfvén wave as it emerges from the inhomogeneous region is studied. Potential applications of this include the magnetospheres of both Jupiter and the Earth. The results show that Alfvén waves can be significantly distorted by a nonuniformity and still propagate through the region efficiently, with relatively small amounts of Alfvén wave energy lost through mode conversion and reflection.

Keywords

• magnetohydrodynamics
• wave mode coupling
• Alfven waves
• magnetospheric physics