The emergence of magnetic flux through a partially ionised solar atmosphere
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 0004-6361Full text not available from this repository.
Official URL: http://dx.doi.org/10.1051/0004-6361:20054099
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|
|Journal or Publication Title:||Astronomy & Astrophysics|
|Number of Pages:||14|
|Page Range:||pp. 805-818|
|Access rights to Published version:||Restricted or Subscription Access|
|Funder:||Particle Physics and Astronomy Research Council (Great Britain) (PPARC)|
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