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dc.contributor.authorFruit, G.
dc.contributor.authorCraig, Ian J.D.
dc.date.accessioned2011-06-28T23:16:55Z
dc.date.available2011-06-28T23:16:55Z
dc.date.issued2006
dc.identifier.citationFruit, G. & Craig, I.J.D. (2006). Rapid dissipation in a current sheet driven by footpoints motions. Astronomy & Astrophysics, 458(1), 307-315.en_NZ
dc.identifier.urihttps://hdl.handle.net/10289/5430
dc.description.abstractContext.Wave energy dissipation by viscous and resistive damping in magnetic coronal plasmas is addressed. A two and one half dimensional, line-tied magnetic channel is considered whose footpoints are disturbed by buffeting motions of the photosphere. Aims.The aim of the analysis is to determine how effectively shear Alfvén waves, driven by footpoint motions and resonating in the channel, can be damped by visco-resistive friction. Methods.The problem is analyzed using a mixture of numerical and analytic techniques. Dynamic simulations, based on a cyclic footpoint driver, show that phase mixing resulting from variations in the magnetic field of the channel is instrumental in setting up a permanent "resonance regime" for the system. Analytic methods are used to analyze the resonance regime and to develop scaling laws for the rate of energy dissipation. Results.We show that in the general case where the Alfvén velocity profile may be linearized around the resonance, the dissipation rate is "fast" in that it is not limited by small damping coefficients. Although large energies can accumulate within the channel in the limit of very small damping, we show that by tuning the driver to low frequencies, both the energy level and the dissipation rate can be made insensitive to the level of the damping.en_NZ
dc.format.mimetypeapplication/pdf
dc.language.isoen
dc.publisherE D P Sciencesen_NZ
dc.relation.urihttp://www.aanda.org/index.php?option=com_article&access=standard&Itemid=129&url=/articles/aa/abs/2006/40/aa5462-06/aa5462-06.htmlen_NZ
dc.rightsThis article has been published in the journal: Astronomy & Astrophysics. Used with permission.en_NZ
dc.subjectMagnetohydrodynamicsen_NZ
dc.subjectcoronaen_NZ
dc.subjectmagnetic fieldsen_NZ
dc.subjectwavesen_NZ
dc.titleRapid dissipation in a current sheet driven by footpoints motionsen_NZ
dc.typeJournal Articleen_NZ
dc.identifier.doi10.1051/0004-6361:20065462en_NZ
dc.relation.isPartOfAstronomy & Astrophysicsen_NZ
pubs.begin-page307en_NZ
pubs.editionOctoberen_NZ
pubs.elements-id32111
pubs.end-page315en_NZ
pubs.issue1en_NZ
pubs.volume458en_NZ


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