Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-22T16:44:13.601Z Has data issue: false hasContentIssue false
  • English
  • Français

3D numerical MHD modeling of sunspots with radiation transport

Published online by Cambridge University Press:  26 August 2011

Matthias Rempel
Matthias Rempel*
Affiliation:
High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307, USA email: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Sunspot fine structure has been modeled in the past by a combination of idealized magneto-convection simulations and simplified models that prescribe the magnetic field and flow structure to a large degree. Advancement in numerical methods and computing power has enabled recently 3D radiative MHD simulations of entire sunspots with sufficient resolution to address details of umbral dots and penumbral filaments. After a brief review of recent developments we focus on the magneto-convective processes responsible for the complicated magnetic structure of the penumbra and the mechanisms leading to the driving of strong horizontal outflows in the penumbra (Evershed effect). The bulk of energy and mass is transported on scales smaller than the radial extent of the penumbra. Strong horizontal outflows in the sunspot penumbra result from a redistribution of kinetic energy preferring flows along the filaments. This redistribution is facilitated primarily through the Lorentz force, while horizontal pressure gradients play only a minor role. The Evershed flow is strongly magnetized: While we see a strong reduction of the vertical field, the horizontal field component is enhanced within filaments.

Keywords

MHDradiative transferSun: sunspotsSun: photosphereSun: magnetic fields
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 6 , Symposium S273: The Physics of Sun and Star Spots , August 2010 , pp. 8 - 14
Copyright
Copyright © International Astronomical Union 2011

References

Franz, M. & Schlichenmaier, R. 2009, A&A, 508, 1453Google Scholar
Heinemann, T., Nordlund, Å., Scharmer, G. B., & Spruit, H. C. 2007, ApJ, 669, 1390Google Scholar
Ichimoto, K., Shine, R. A., Lites, B., Kubo, M., Shimizu, T., Suematsu, Y., Tsuneta, S., Katsukawa, Y., Tarbell, T. D., Title, A. M., Nagata, S., Yokoyama, T., & Shimojo, M. 2007, Publ. Astron. Soc. Jpn., 59, 593CrossRefGoogle Scholar
Kitiashvili, I. N., Kosovichev, A. G., Wray, A. A., & Mansour, N. N. 2009, ApJL, 700, L178CrossRefGoogle Scholar
Montesinos, B. & Thomas, J. H. 1997, Nature, 390, 485CrossRefGoogle Scholar
Rempel, M. 2010, ApJ, submittedGoogle Scholar
Rempel, M., Schüssler, M., & Knólker, M. 2009a, ApJ, 691, 640CrossRefGoogle Scholar
Rempel, M., Schüssler, M., Cameron, R. H., & Knólker, M. 2009b, Science, 325, 171CrossRefGoogle Scholar
Scharmer, G. B., Gudiksen, B. V., Kiselman, D., Löfdahl, M. G. & Rouppe van der Voort, L. H. M. 2002, Nature, 420, 151CrossRefGoogle Scholar
Scharmer, G. B., Nordlund, Å., & Heinemann, T. 2008, ApJL, 677, L149Google Scholar
Scharmer, G. B. & Spruit, H. C. 2006, A&A, 460, 605Google Scholar
Schlichenmaier, R., Jahn, K., & Schmidt, H. U. 1998a, ApJ, 493, L121Google Scholar
Schlichenmaier, R., Jahn, K., & Schmidt, H. U. 1998b, A&A, 337, 897Google Scholar
Schüssler, M. & Vógler, A. 2006, ApJL, 641, L73CrossRefGoogle Scholar
Solanki, S. K. 2003, A&A, 11, 153Google Scholar
Spruit, H. C. & Scharmer, G. B. 2006, A&A, 447, 343Google Scholar
Tritschler, A., Müller, D. A. N., Schlichenmaier, R., & Hagenaar, H. J. 2007, ApJL, 671, L85Google Scholar