Botha, G.J.J., Rucklidge, A.M. orcid.org/0000-0003-2985-0976 and Hurlburt, N.E. (2007) Nonaxisymmetric instabilities of convection around magnetic flux tubes. The Astrophysical Journal, 662 (1). L27-L30. ISSN 0004-637X
Abstract
On the surface of the Sun, magnetic flux elements collect in regions of converging flow, grow in field strength, and become pores, which have been observed to exhibit nonaxisymmetric structure over a range of scales. Around a fully developed sunspot, as well as the fine scale of the penumbra, the moat sometimes shows a clearly observable spokelike structure at low azimuthal wavenumbers. We investigate the formation of azimuthal structure by computing the linear stability properties of fully nonlinear axisymmetric magnetoconvection, which takes the form of a central flux tube surrounded by a convecting field-free region. We find steady and oscillatory instabilities with a preferred azimuthal wavenumber. The unstable modes are concentrated in the convecting region close to the outer edge of the flux tube. The instability is driven by convection and is not a magnetic fluting instability.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use (https://www.springernature.com/gp/open-research/policies/accepted-manuscript-terms), but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1086/519079. |
Keywords: | Magnetic Fields; sunspots; MHD convection |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | ?? Leeds.SU-MTHA ?? The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mathematics (Leeds) > Applied Mathematics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 12 Feb 2025 10:01 |
Last Modified: | 12 Feb 2025 10:01 |
Published Version: | https://iopscience.iop.org/article/10.1086/519079 |
Status: | Published |
Publisher: | University of Chicago Press, Journals Division |
Identification Number: | 10.1086/519079 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:223208 |