Astron. Astrophys. 326, 1241-1251
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Absorption of magnetosonic waves in presence
of resonant slow waves in the solar atmosphere
V.M. ade*, Á. Csík**, and R. Erdélyi***, and M. Goossens
Center for Plasma-Astrophysics, K.U. Leuven,
Celestijnenlaan 200 B, B-3001 Heverlee, Belgium
Received 10 March 1997 / Accepted 12 May 1997
The resonant absorption of slow and fast magnetosonic waves in a nonuniform magnetic
plasma is studied for a simple planar equilibrium model.
Propagating slow and fast magnetosonic waves are launched upwards
in a lower uniform layer. They are partially
absorbed by coupling to local resonant waves in an overlying
nonuniform plasma layer at the magnetic surface
where the frequency of the incoming wave equals the local Alfvén continuum
frequency or the local slow continuum frequency.
The slow magnetosonic waves can only be coupled to resonant slow
continuum waves. For the fast magnetosonic waves there are three possibilities
as they can be coupled to resonant Alfvén continuum waves alone, resonant
Alfvén continuum waves combined with resonant slow continuum waves, and resonant
slow continuum waves alone.
The present paper focuses on the absorption of magnetosonic waves by coupling to
resonant slow continuum waves either alone or in combination with resonant Alfvén
The results show that the resonant absorption of slow and fast magnetosonic
waves at the slow resonance position strongly depends on the characteristics of the
equilibrium model and of the driving wave. The absorption can produce
efficient local heating of plasma under conditions as in the solar atmosphere.
Key words: Magnetohydrodynamics (MHD) - methods: numerical - Sun:
corona - Sun: oscillations
*On leave from Institute of Physics, P.O. Box 57, YU-11000 Beograd,
**On leave from Department of Astronomy, Eötvös University Budapest,
Ludovika tér 2 H-1083 Budapest, Hungary.
***Armagh Observatory, College Hill, Armagh, BT61 9DG, Northern Ireland.
Send offprint requests to: Á. Csík
© European Southern Observatory (ESO) 1997
Online publication: October 1, 1997
Last change: April 8, 1998