Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-13T10:21:50.708Z Has data issue: false hasContentIssue false
  • English
  • Français

Helical Surface Structures

Published online by Cambridge University Press:  26 May 2016

Axel Brandenburg  and
Eric G. Blackman
Axel Brandenburg
Affiliation:
Nordita, Blegdamsvej 17, DK-2100 Copenhagen ø, Denmark
Eric G. Blackman
Affiliation:
Department of Physics & Astronomy, University of Rochester, Rochester NY 14627

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.

Over the past few years there has been growing interest in helical magnetic field structures seen at the solar surface, in coronal mass ejections, as well as in the solar wind. Although there is a great deal of randomness in the data, on average the extended structures are mostly left-handed on the northern hemisphere and right-handed on the southern. Surface field structures are also classified as dextral (= right bearing) and sinistral (= left bearing) occurring preferentially in the northern and southern hemispheres respectively. Of particular interest here is a quantitative measurement of the associated emergence rates of helical structures, which translate to magnetic helicity fluxes. In this review, we give a brief survey of what has been found so far and what is expected based on models. Particular emphasis is put on the scale dependence of the associated fields and an attempt is made to estimate the helicity flux of the mean field vs. fluctuating field.

Type
Session D. Atmospheric Inhomogeneities
Information
Symposium - International Astronomical Union , Volume 210: Modelling of Stellar Atmospheres , 2003 , pp. 233 - 242
Copyright
Copyright © Astronomical Society of the Pacific 2003 

References

Abbett, W. P., Fisher, G. H., & Fan, Y. 2000, ApJ, 540, 548 Google Scholar
Bao, S. D., Zhang, H. Q., Ai, G. X., & Zhang, M. 1999, A&AS, 139, 311 Google Scholar
Berger, M., & Field, G. B. 1984, JFM, 147, 133 Google Scholar
Berger, M. A., & Ruzmaikin, A. 2000, JGR, 105, 10481 Google Scholar
Blackman, E. G. & Field, G. B. 2000, MNRAS, 318, 724 Google Scholar
Brandenburg, A. 1998, in Theory of Black Hole Accretion Discs, ed. Abramowicz, M. A., Björnsson, G. & Pringle, J. E. (Cambridge University Press), 61 Google Scholar
Brandenburg, A. 2001, ApJ, 550, 824 Google Scholar
Brandenburg, A. 2002, in Simulations of magnetohydrodynamic turbulence in astrophysics, ed. Passot, T. & Falgarone, E. (Springer Lecture Notes in Physics), (in press) (astro-ph/0207394) Google Scholar
Brandenburg, A., & Dobler, W. 2001, A&A, 369, 329 Google Scholar
Brandenburg, A., Bigazzi, A., & Subramanian, K. 2001, MNRAS, 325, 685 CrossRefGoogle Scholar
Brandenburg, A., Dobler, W., & Subramanian, K. 2002, AN, 323, 99 (astro-ph/0111567) Google Scholar
Chae, J. 2000, ApJ, 540, L115 Google Scholar
Choudhuri, A. R., Schüssler, M., & Dikpati, M. 1995, A&A, 303, L29 Google Scholar
DeVore, C. R. 2000, ApJ, 539, 944 CrossRefGoogle Scholar
Durney, B. R. 1995, Solar Phys., 166, 231 Google Scholar
Ji, H. 1999, PRL, 83, 3198 Google Scholar
Krause, F., & Rädler, K.-H. 1980, Mean-Field Magnetohydrodynamics and Dynamo Theory (Akademie-Verlag, Berlin; also Pergamon Press, Oxford)Google Scholar
Küker, M., Rüdiger, G., & Schultz, M. 2001, A&A, 374, 301 Google Scholar
Low, B. C. 2001, JGR, 106, 25,141 Google Scholar
Moffatt, H. K. 1978, Magnetic Field Generation in Electrically Conducting Fluids (Cambridge University Press, Cambridge)Google Scholar
Parker, E. N. 1955, ApJ, 122, 293 Google Scholar
Parker, E. N. 1979, Cosmical Magnetic Fields (Clarendon Press, Oxford)Google Scholar
Pevtsov, A. A. & Latushko, S. M. 2000, ApJ, 528, 999 Google Scholar
Pevtsov, A. A., Canfield, R. C., & Metcalf, T. R. 1995, ApJ, 440, L109 Google Scholar
Pouquet, A., Frisch, U., & Léorat, J. 1976, JFM, 77, 321 Google Scholar
Rust, D. M. & Kumar, A. 1996, ApJ, 464, L199 Google Scholar
Rädler, K.-H., & Seehafer, N. 1990, in Topological Fluid Mechanics, ed. Moffatt, H. K. & Tsinober, A. (Cambridge University Press, Cambridge), 157 Google Scholar
Seehafer, N. 1990, Solar Phys., 125, 219 Google Scholar
Seehafer, N. 1996, Phys. Rev., E 53, 1283 Google Scholar
Stix, M. 1976, A&A, 47, 243 Google Scholar
Zeldovich, Ya. B., Ruzmaikin, A. A., Sokoloff, D. D. 1983, Magnetic fields in astrophysics (Gordon & Breach, New York)Google Scholar
Yoshimura, H. 1976, Solar Phys., 50, 3 Google Scholar