Kinetic Alfven waves and plasma transport at the magnetopause [report]

J.R. Johnson, C.Z. Cheng
1997 unpublished
Large amplitude compressional type waves, with frequencies ranging from 10-500 mHz, are nearly always found in the magnetosheath near the magnetopause where there are large gradients in density, pressure and magnetic field. As compressional waves propagate to the magnetopause, these gradients efficiently couple them with shear/kinetic Alfvbn waves near the Alfvdn field-line resonance location (w = Ic1p~). We present a solution of the kinetic-MHD wave equations for this process using a realistic
more » ... equilibrium profile including fulI 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 IC11 = 0 location. The quasi-linear theory predicts that KAWs produce plasma transport with a diffusion coefficient Dl N lo9 m2/s and plasma convection on the order of 1 km/s. However, for southward IMF additional transport can occur because magnetic islands form at the LII = 0 location. Due to the broadband nature of the observed waves these islands can overlap leading to stochastic transport which is much larger than that due to quasilinear effects.
doi:10.2172/304098 fatcat:o3aqc2yyjzfipim3zoayvwkwlm