Observational evidence of resonantly damped propagating kink waves in the solar corona

Verth, Gary, Terradas, Jaume and Goossens, Marcel (2010) Observational evidence of resonantly damped propagating kink waves in the solar corona. The Astrophysical Journal, 718 (2). L102-L105. ISSN 0004-637X

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Abstract

In this Letter, we establish clear evidence for the resonant absorption damping mechanism by analyzing observational data from the novel Coronal Multi-Channel Polarimeter. This instrument has established that in the solar corona there are ubiquitous propagating low-amplitude (1 km s–1) Alfvénic waves with a wide range of frequencies. Realistically interpreting these waves as the kink mode from magnetohydrodynamic wave theory, they should exhibit a frequency-dependent damping length due to resonant absorption, governed by the Terradas-Goossens-Verth relation showing that transverse plasma inhomogeneity in coronal magnetic flux tubes causes them to act as natural low-pass filters. It is found that the observed frequency dependence on damping length (up to about 8 mHz) can be explained by the kink wave interpretation; and furthermore, the spatially averaged equilibrium parameter describing the length scale of transverse plasma density inhomogeneity over a system of coronal loops is consistent with the range of values estimated from Transition Region and Coronal Explorer observations of standing kink modes.

Item Type:	Article
Uncontrolled Keywords:	magnetic fields, magnetohydrodynamics (MHD), plasmas, Sun: corona, Sun: oscillations
Subjects:	F300 Physics G100 Mathematics
Department:	Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User:	EPrint Services
Date Deposited:	26 Apr 2011 11:42
Last Modified:	13 Oct 2019 00:30
URI:	http://nrl.northumbria.ac.uk/id/eprint/929

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