Astronomy and Astrophysics – Astrophysics – Solar and Stellar Astrophysics
Scientific paper
2010-07-12
Astronomy and Astrophysics
Astrophysics
Solar and Stellar Astrophysics
23 pages, 8 figures, 2 tables; accepted by Solar Phys (July 9 2010)
Scientific paper
Resonant absorption and mode conversion are both extensively studied mechanisms for wave "absorption" in solar magnetohydrodynamics (MHD). But are they really distinct? We re-examine a well-known simple resonant absorption model in a cold MHD plasma that places the resonance inside an evanescent region. The normal mode solutions display the standard singular resonant features. However, these same normal modes may be used to construct a ray bundle which very clearly undergoes mode conversion to an Alfv\'en wave with no singularities. We therefore conclude that resonant absorption and mode conversion are in fact the same thing, at least for this model problem. The prime distinguishing characteristic that determines which of the two descriptions is most natural in a given circumstance is whether the converted wave can provide a net escape of energy from the conversion/absorption region of physical space. If it cannot, it is forced to run away in wavenumber space instead, thereby generating the arbitrarily small scales in situ that we recognize as fundamental to resonant absorption and phase mixing. On the other hand, if the converted wave takes net energy way, singularities do not develop, though phase mixing may still develop with distance as the wave recedes.
Andries Jesse
Cally Paul S.
No associations
LandOfFree
Resonant Absorption as Mode Conversion? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Resonant Absorption as Mode Conversion?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Resonant Absorption as Mode Conversion? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-695336