A Full-wave Model for Wave Propagation and Dissipation in the Inner Magnetosphere Using the Finite Element Method
Authors: Ernest Valeo, Jay R. Johnson, Eun-Hwa and Cynthia Phillips
Abstract:
A wide variety of plasma waves play an important role in the energization and loss of
particles in the inner magnetosphere. Our ability to understand and model wave-particle
interactions in this region requires improved knowledge of the spatial distribution and
properties of these waves as well as improved understanding of how the waves depend on
changes in solar wind forcing and/or geomagnetic activity. To this end, we have developed a
two-dimensional, finite element code that solves the full wave equations in global
magnetospheric geometry. The code describes three-dimensional wave structure including
mode conversion when ULF, EMIC, and whistler waves are launched in a two-dimensional
axisymmetric background plasma with general magnetic field topology. We illustrate the
capabilities of the code by examining the role of plasmaspheric plumes on magnetosonic
wave propagation; mode conversion at the ion-ion and Alfven resonances resulting from
external, solar wind compressions; and wave structure and mode conversion of
electromagnetic ion cyclotron waves launched in the equatorial magnetosphere, which
propagate along the magnetic field lines toward the ionosphere. We also discuss advantages
of the finite element method for resolving resonant structures, and how the model may be
adapted to include nonlocal kinetic effects.
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Submitted to: 2011 AGU Fall meeting/San Francisco, CA 12/6/11
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Download PPPL-4743 (pdf 709 KB 8 pp)
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