On the fragility of Alfvén waves in a stratified atmosphere

ABSTRACT Complete asymptotic expansions are developed for slow, Alfvén, and fast magnetohydrodynamic waves at the base of an isothermal 3D plane stratified atmosphere. Together with existing convergent Frobenius series solutions about z = ∞, matchings numerically calculated that illuminate fates slow Alfvén injected from below. An wave in a two-dimensional model is 2.5D sense propagates magnetic field but its polarization normal to it ignorable horizontal direction, remains throughout. The rotation propagation away vertical pushes plasma displacement vector horizontal, thereby coupling stratification. It shown potent slow–Alfvén occurs such models. found 50 per cent direction-averaged flux generated low atmosphere frequencies comparable or greater than acoustic cut-off can reach top as small inclinations θ, this increases 80 more increasing θ. On other hand, be 40 effective converting inclination, reduces sharply θ frequency. previously explored fast–slow fast–Alfvén couplings, provides valuable insights into which transverse upper waves, implications solar stellar coronal heating solar/stellar wind acceleration.