Surface Alfven Wave Damping in a Solar Wind Simulation Driven by Alfven Waves
Abstract
We present results in an effort to develop a solar wind model driven by Alfven waves with realistic damping mechanisms. Here we investigate the contribution of surface Alfven wave damping to the heating of the solar wind in minima conditions. These waves are present and damp in regions of strong gradients in density or magnetic field (e.g., the border between open and closed magnetic field lines). By considering the geometry of open field lines and the background solar wind in these regions, we showed that surface Alfven wave contribution to heating is on the order of the heating by a variable polytropic index in the semiempirical thermodynamics model of Cohen et al. (Evans et al. 2009). Recently Oran et al. implemented a first principle steady state solar wind driven by a spectrum of Alfven waves in the SWMF. The waves contribute to the momentum and the energy of the wind. The wave transport equation, including wave advection and dissipation, is coupled to the MHD equations for the wind. In this work we extend this model to include surface Alfven wave damping, considering waves with frequencies lower than those that are damped in the chromosphere and on the order of those dominating the heliosphere (0.0001 to 100 Hz.) We compare to results of the variable polytropic index model, and a wind driven solely by Alfven wave pressure. This work is the first to study surface Alfven waves self-consistently as an energy driven for the solar wind in a 4D (three in space and one in frequency) environment.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2009
- Bibcode:
- 2009AGUFMSH53A1309E
- Keywords:
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- 7509 SOLAR PHYSICS;
- ASTROPHYSICS;
- AND ASTRONOMY / Corona;
- 7863 SPACE PLASMA PHYSICS / Turbulence;
- 7868 SPACE PLASMA PHYSICS / Wave/wave interactions;
- 7959 SPACE WEATHER / Models