Kinetic Alfvén waves and plasma transport at the magnetopause
Article first published online: 7 DEC 2012
Copyright 1997 by the American Geophysical Union.
Geophysical Research Letters
Volume 24, Issue 11, pages 1423–1426, 1 June 1997
How to Cite
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Accepted: 30 APR 1997
- Manuscript Received: 24 JAN 1997
Large amplitude compressional type ULF waves can propagate from the magnetosheath to the magnetopause where there are large gradients in density, pressure and magnetic field. These gradients efficiently couple compressional waves with shear/kinetic Alfvén waves near the Alfvén field-line resonance location (ω=k∥υA). We present a solution of the kinetic-MHD wave equations for this process using a realistic equilibrium profile including full ion Larmor radius effects and wave-particle resonance interactions for electrons and ions to model the dissipation. For northward IMF a KAW propagates backward to the magnetosheath. For southward IMF the wave remains in the magnetopause but can propagate through the k∥=0 location. The quasilinear theory predicts that transport due to KAWs at the magnetopause primarily results from the perpendicular electric field coupling with magnetic drift effects with diffusion coefficient D⟂ ∼ 109 m²/s. For southward IMF additional transport can occur because magnetic islands form at the k∥=0 location. Due to the broadband nature of the observed waves these islands can overlap leading to stochastic transport which is larger than that due to quasilinear effects.