Leake, J. E. (James E.) and Arber, T. D.. (2006) The emergence of magnetic flux through a partially ionised solar atmosphere. Astronomy & Astrophysics, Vol.450 (No.2). pp. 805-818. ISSN 0004-6361

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Abstract

We present results from 2.5D numerical simulations of the emergence of magnetic flux from the upper convection zone through the photosphere and chromosphere into the corona. Certain regions of the solar atmosphere are at sufficiently low temperatures to be only partially ionised, in particular the lower chromosphere. This leads to Cowling resistivities orders of magnitude larger than the Coulomb values, and thus to anisotropic dissipation in Ohm’s law. This also leads to localised low magnetic Reynolds numbers (R m < 1). We find that the rates of emergence of magnetic field are greatly increased by the partially ionised regions of the model atmosphere, and the resultant magnetic field is more diffuse. More importantly, the only currents associated with the magnetic field to emerge into the corona are aligned with the field, and thus the newly formed coronal field is force-free.

Item Type:	Journal Article
Subjects:	Q Science > QB Astronomy
Divisions:	Faculty of Science > Physics
Library of Congress Subject Headings (LCSH):	Sun -- Corona -- Magnetic fields -- Mathematical models, Magnetohydrodynamics
Journal or Publication Title:	Astronomy & Astrophysics
Publisher:	EDP Sciences
ISSN:	0004-6361
Date:	May 2006
Volume:	Vol.450
Number:	No.2
Page Range:	pp. 805-818
Identification Number:	10.1051/0004-6361:20054099
Status:	Peer Reviewed
Access rights to Published version:	Open Access
Funder:	Particle Physics and Astronomy Research Council (Great Britain) (PPARC)
Grant number:	PPA/S/S/2003/03728 (PPARC)
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URI:	http://wrap.warwick.ac.uk/id/eprint/3547

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