Wave leakage in a magnetized isothermal atmosphere

Abstract

The present investigation is a continuation of earlier work by Hasan & christensen-Dalsgaard (1992) and Banerjee, Hasan & Christensen-Dalsgaard(1995), where the interaction of various elementary modes in a stratified atmosphere with a vertical magnetic field was studied. In the present study, we concentrate on the behaviour of the modes near the avoided crossings in the k-w diagram for zero-gradient boundary conditions. We find that in such regions the frequencies of the modes become complex, whereas away from the avoided crossing the frequencies are real (in the adiabatic case) for these boundary conditions. Strong mode coupling in the avoided-crossing regions permits energy leakage for zero-gradient boundary conditions.