Hostname: page-component-8448b6f56d-c4f8m Total loading time: 0 Render date: 2024-04-17T13:05:34.540Z Has data issue: false hasContentIssue false
  • English
  • Français

Magnetic helicity evolution inside a hexagonal convective cell

Published online by Cambridge University Press:  08 June 2011

Aimilia Smyrli ,
Duncan Mackay  and
Francesca Zuccarello
Aimilia Smyrli
Affiliation:
Dipartimento di Fisica e Astronomia - Sezione Astrofisica, Via S. Sofia 78, 95123 Catania, Italy email: emilia@oact.inaf.it School of Mathematics and Statistics, University of St. Andrews, The North Haugh, St. Andrews, Fife KY 169SS, Scotland, U.K.
Duncan Mackay
Affiliation:
School of Mathematics and Statistics, University of St. Andrews, The North Haugh, St. Andrews, Fife KY 169SS, Scotland, U.K.
Francesca Zuccarello
Affiliation:
Dipartimento di Fisica e Astronomia - Sezione Astrofisica, Via S. Sofia 78, 95123 Catania, Italy email: emilia@oact.inaf.it
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.

Magnetic helicity has received considerable attention in the area of fluid dynamics. Recently, this quantity is attracting the interest of solar physicists and much research has been carried out related to magnetic helicity generation and transport through different solar layers, starting from the interior and the convection zone, towards the photosphere, the corona and finally into the heliosphere. Taking into account the global importance of supergranular cells in convection theories, we study the motion of magnetic features into such a geometrical element simplified as hexagonal cell and we analyse the results in terms of the accumulated magnetic helicity. We compute the emergence of a bipole inside the hexagonal cell and its motion from the centre of the cell towards its sides and its vertices, where the magnetic elements are considered to be sinking down. Multiple bipoles are also considered and phenomena such as cancellation, coalescence and fragmentation are also investigated. We find that the most important process for the accumulation of magnetic helicity is the shear motion between the polarities. The magnetic helicity accumulation changes its trend when one polarity reaches the side of the hexagon, and later the vertex. It has zero value when there is no shear motion inside the hexagonal cell, and it is constant when there is no shear between the two polarities during their motion along the cell sides.

Keywords

Sun: photosphereSun: interiorconvectionSun: magnetic fields
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 6 , Symposium S274: Advances in Plasma Astrophysics , September 2010 , pp. 192 - 194
Copyright
Copyright © International Astronomical Union 2011

References

Berger, M. A. & Field, G. B. 1984, J. Fluid Mech., 147, 133CrossRefGoogle Scholar
Chae, J. 2001, ApJ, 560, L95CrossRefGoogle Scholar
Mackay, D. H., Priest, E. R., & Lockwood, M. 2002, Sol. Phys., 209, 287CrossRefGoogle Scholar
Mackay, D. H. & Gaizauskas, V. 2003, Sol. Phys., 216, 121CrossRefGoogle Scholar
Park, J., Chae, J., Haimin, W. 2010, ApJ, in pressGoogle Scholar
Parnell, C. E. 2001, Sol. Phys, 200, 23CrossRefGoogle Scholar
Priest, E. R., Heyvaerts, J. F., & Title, A. M. 2002, ApJ, 576, 533CrossRefGoogle Scholar
Romano, P., Contarino, L., & Zuccarello, F. 2003, Sol.Phys., 218, 137CrossRefGoogle Scholar
Smyrli, A., Zuccarello, F., Romano, P., Zuccarello, F. P., Guglielmino, S. L., Spadaro, D., Hood, A. W., & Mackay, D. H., 2010, A & A, in pressGoogle Scholar