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dc.contributor.authorFuentes Fernandez, Jorge
dc.contributor.authorParnell, Clare Elizabeth
dc.contributor.authorHood, Alan William
dc.identifier.citationFuentes Fernandez , J , Parnell , C E & Hood , A W 2010 , ' Magnetohydrodynamics dynamical relaxation of coronal magnetic fields : I. Parallel untwisted magnetic fields in 2D ' , Astronomy & Astrophysics , vol. 514 , A90 .
dc.identifier.otherPURE: 5022511
dc.identifier.otherPURE UUID: 9e9ee2db-4129-448d-8083-267b3534bd05
dc.identifier.otherScopus: 77952948432
dc.identifier.otherORCID: /0000-0003-2620-2068/work/58055119
dc.identifier.otherORCID: /0000-0002-5694-9069/work/73700704
dc.description.abstractContext. For the last thirty years, most of the studies on the relaxation of stressed magnetic fields in the solar environment have only considered the Lorentz force, neglecting plasma contributions, and therefore, limiting every equilibrium to that of a force-free field. Aims: Here we begin a study of the non-resistive evolution of finite beta plasmas and their relaxation to magnetohydrostatic states, where magnetic forces are balanced by plasma-pressure gradients, by using a simple 2D scenario involving a hydromagnetic disturbance to a uniform magnetic field. The final equilibrium state is predicted as a function of the initial disturbances, with aims to demonstrate what happens to the plasma during the relaxation process and to see what effects it has on the final equilibrium state. Methods: A set of numerical experiments are run using a full MHD code, with the relaxation driven by magnetoacoustic waves damped by viscous effects. The numerical results are compared with analytical calculations made within the linear regime, in which the whole process must remain adiabatic. Particular attention is paid to the thermodynamic behaviour of the plasma during the relaxation. Results: The analytical predictions for the final non force-free equilibrium depend only on the initial perturbations and the total pressure of the system. It is found that these predictions hold surprisingly well even for amplitudes of the perturbation far outside the linear regime. Conclusions: Including the effects of a finite plasma beta in relaxation experiments leads to significant differences from the force-free case.
dc.relation.ispartofAstronomy & Astrophysicsen
dc.rights© 2010, ESO. A&A 514, A90 (2010). Reproduced with permission from the publishers.en
dc.subjectMagnetohydrodynamics (MHD)en
dc.subjectMagnetic fieldsen
dc.subjectQB Astronomyen
dc.titleMagnetohydrodynamics dynamical relaxation of coronal magnetic fields : I. Parallel untwisted magnetic fields in 2Den
dc.typeJournal articleen
dc.contributor.sponsorPPARC - Now STFCen
dc.description.versionPublisher PDFen
dc.contributor.institutionUniversity of St Andrews. School of Mathematics and Statisticsen
dc.contributor.institutionUniversity of St Andrews. Applied Mathematicsen
dc.description.statusPeer revieweden

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