EDP Sciences
Free access
Issue
A&A
Volume 438, Number 2, August I 2005
Page(s) 733 - 740
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20042527


A&A 438, 733-740 (2005)
DOI: 10.1051/0004-6361:20042527

Damping of vertical coronal loop kink oscillations through wave tunneling

C. S. Brady and T. D. Arber

Physics Department, University of Warwick, CV4 7AL, Coventry, UK
    e-mail: bradyc@astro.warwick.ac.uk

(Received 13 December 2004 / Accepted 11 April 2005)

Abstract
The decay rate of vertical kink waves in a curved flux tube is modeled numerically. The full MHD equations are solved for a curved equilibrium flux tube in an arcade geometry and the decay of $\psi$, the integral over the flux tube of the modulus of the velocity perpendicular to the local magnetic field, is measured. These simulations are 2D and are thus restricted to kink oscillations in the loop plane. The decay rate is found to increase with increasing wavelength, increasing $\beta$ and decreasing density contrast ratio. The wave tunneling effect is shown to be a possible mechanism for the high decay rate of the recent observed kink oscillation reported by Wang & Solanki (2004).


Key words: Sun: corona -- Sun: magnetic fields -- Sun: oscillations




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