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Abstract
Aims.
To investigate the spatial damping of propagating kink waves in an inhomogeneous plasma. In the limit of a thin tube surrounded by a thin transition layer, an analytical formulation for kink waves driven in from the bottom boundary of the corona is presented.
Methods.
The spatial form for the damping of the kink mode was investigated using various analytical approximations. When the density ratio between the internal density and the external density is not too large, a simple di.erentialintegral equation was used. Approximate analytical solutions to this equation are presented.
Results.
For the first time, the form of the spatial damping of the kink mode is shown analytically to be Gaussian in nature near the driven boundary. For several wavelengths, the amplitude of the kink mode is proportional to (1 + exp(z2 /L2
g))/2, where L2g = 16/ǫκ2 k2 . Although the actual value of 16 in Lg depends on the particular form of the driver, this form is very general and its dependence on the other parameters does not change. For large distances, the damping profile appears to be roughly linear exponential decay. This is shown analytically by a series expansion when the inhomogeneous layer width is small enough.
To investigate the spatial damping of propagating kink waves in an inhomogeneous plasma. In the limit of a thin tube surrounded by a thin transition layer, an analytical formulation for kink waves driven in from the bottom boundary of the corona is presented.
Methods.
The spatial form for the damping of the kink mode was investigated using various analytical approximations. When the density ratio between the internal density and the external density is not too large, a simple di.erentialintegral equation was used. Approximate analytical solutions to this equation are presented.
Results.
For the first time, the form of the spatial damping of the kink mode is shown analytically to be Gaussian in nature near the driven boundary. For several wavelengths, the amplitude of the kink mode is proportional to (1 + exp(z2 /L2
g))/2, where L2g = 16/ǫκ2 k2 . Although the actual value of 16 in Lg depends on the particular form of the driver, this form is very general and its dependence on the other parameters does not change. For large distances, the damping profile appears to be roughly linear exponential decay. This is shown analytically by a series expansion when the inhomogeneous layer width is small enough.
Original language  English 

Article number  A39 
Number of pages  14 
Journal  Astronomy & Astrophysics 
Volume  551 
Early online date  4 Jan 2013 
DOIs  
Publication status  Published  Mar 2013 
Keywords
 Magnetohydrodynamics (MHD)
 Sun: atmosphere
 Sun: magnetic topology
 Sun: oscillations
 Waves
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Dive into the research topics of 'Damping of kink waves by mode coupling: I. Analytical treatment'. Together they form a unique fingerprint.Projects
 2 Finished

Plasma Theory: Solar and Magnetospheric Plasma Theory
Hood, A. W., Mackay, D. H., Neukirch, T., Parnell, C. E., Priest, E., Archontis, V., Cargill, P., De Moortel, I. & Wright, A. N.
Science & Technology Facilities Council
1/04/13 → 31/03/16
Project: Standard

RS Ext.to XCHY49 Uni Research Fellowship: Coronal Seismology from Concept to Realisation
1/10/09 → 31/12/13
Project: Fellowship