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Non-linear and chaotic dynamo regimes

Published online by Cambridge University Press:  18 July 2013

Axel Brandenburg
Axel Brandenburg*
Affiliation:
Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden Department of Astronomy, Stockholm University, SE-10691 Stockholm, Sweden
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Abstract

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An update is given on the current status of solar and stellar dynamos. At present, it is still unclear why stellar cycle frequencies increase with rotation frequency in such a way that their ratio increases with stellar activity. The small-scale dynamo is expected to operate in spite of a small value of the magnetic Prandtl number in stars. Whether or not the global magnetic activity in stars is a shallow or deeply rooted phenomenon is another open question. Progress in demonstrating the presence and importance of magnetic helicity fluxes in dynamos is briefly reviewed, and finally the role of nonlocality is emphasized in modeling stellar dynamos using the mean-field approach. On the other hand, direct numerical simulations have now come to the point where the models show solar-like equatorward migration that can be compared with observations and that need to be understood theoretically.

Keywords

MHD – turbulence – Sun: magnetic fields
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 8 , Symposium S294: Solar and Astrophysical Dynamos and Magnetic Activity , August 2012 , pp. 387 - 398
Copyright
Copyright © International Astronomical Union 2013 

References

Abramenko, V. I., Carbone, V., Yurchyshyn, V., Goode, P. R., Stein, R. F., Lepreti, F., Capparelli, V., & Vecchio, A. 2011 ApJ, 743 133 CrossRefGoogle Scholar
Aurière, M., Donati, J.-F., Konstantinova-Antova, R., Perrin, G., Petit, P., & Roudier, T. 2010 A&A, 516 L2 Google Scholar
Bingert, S. & Peter, H. 2011 A&A, 530 A112 Google Scholar
Blackman, E. G. & Brandenburg, A. 2003 ApJL, 584 L99 CrossRefGoogle Scholar
Boldyrev, S. & Cattaneo, F. 2004 Phys. Rev. Lett., 92 144501 CrossRefGoogle Scholar
Brown, B. P., Miesch, M. S., Browning, M. K., Brun, A. S., & Toomre, J. 2011 ApJ, 731 69 Google Scholar
Brandenburg, A. 2005 ApJ, 625 539 Google Scholar
Brandenburg, A. 2009 ApJ, 697 1206 CrossRefGoogle Scholar
Brandenburg, A. 2011 ApJ, 741 92 Google Scholar
Brandenburg, A., Saar, S. H., & Turpin, C. R. 1998 ApJL, 498 L51 Google Scholar
Brandenburg, A., Rädler, K.-H., & Schrinner, M. 2008 A&A, 482 739 Google Scholar
Brandenburg, A., Kemel, K., Kleeorin, N., Mitra, Dhrubaditya & Rogachevskii, I. 2011a ApJL, 740 L50 Google Scholar
Brandenburg, A., Subramanian, K., Balogh, A., & Goldstein, M. L. 2011b ApJ, 9 734 Google Scholar
Brandenburg, A., Kemel, K., Kleeorin, N., & Rogachevskii, I. 2012 ApJ, 749 179 Google Scholar
Brown, B. P., Browning, M. K., Brun, A. S., Miesch, M. S., & Toomre, J. 2010 ApJ, 711 424 Google Scholar
Cattaneo, F. 1999 ApJ, 515 L39 CrossRefGoogle Scholar
Cattaneo, F., Emonet, T., & Weiss, N. 2003 ApJ, 588 1183 Google Scholar
Chatterjee, P., Nandy, D., & Choudhuri, A. R. 2004 A&A, 427 1019 Google Scholar
Chatterjee, P., Mitra, D., Rheinhardt, M. & Brandenburg, A. 2011 A&A, 534 A46 Google Scholar
Cline, K. S., Brummell, N. H., & Cattaneo, F. 2003 ApJ, 599 1449 CrossRefGoogle Scholar
Danilovic, S., Schssler, M., & Solanki, S. K. 2010 A&A, 513 A1 Google Scholar
Del Sordo, F., Guerrero, G., & Brandenburg, A. 2013 MNRAS, 429 1686 Google Scholar
Dobler, W., Haugen, N. E. L., Yousef, T. A., & Brandenburg, A. 2003 Phys. Rev. E, 68 026304 CrossRefGoogle Scholar
Falkovich, G. 1994 Phys. Fluids, 6 1411 Google Scholar
Gibson, S. E., Fletcher, L., Del Zanna, G., et al. 2002 ApJ, 574 1021 Google Scholar
Ghizaru, M., Charbonneau, P., & Smolarkiewicz, P. K. 2010 ApJL, 715 L133 Google Scholar
Golitsyn, G. S. 1960 Sov. Phys. Dokl., 5 536 Google Scholar
Guerrero, G. & Käpylä, P. J. 2011 A&A, 533 A40 Google Scholar
Hindman, B. W., Haber, D. A., & Toomre, J. 2009 ApJ, 698 1749 CrossRefGoogle Scholar
Hubbard, A. & Brandenburg, A. 2010 Geophys. Astrophys. Fluid Dyn., 104 577 Google Scholar
Ilonidis, S., Zhao, J., & Kosovichev, A. 2011 Science, 333 993 Google Scholar
Ishikawa, R. & Tsuneta, S. 2009 A&A, 495 607 Google Scholar
Iskakov, A. B., Schekochihin, A. A., Cowley, S. C., McWilliams, J. C., & Proctor, M. R. E. 2007 Phys. Rev. Lett., 98 208501 Google Scholar
Kaneda, Y., Ishihara, T., Yokokawa, M., Itakura, K., & Uno, A. 2003 Phys. Fluids, 15 L21 Google Scholar
Käpylä, P. J., Korpi, M. J., Brandenburg, A., Mitra, D., & Tavakol, R. 2010 Astron. Nachr., 331 73 Google Scholar
Käpylä, P. J., Mantere, M. J., & Brandenburg, A. 2012 ApJL, 755 L22 Google Scholar
Käpylä, P. J., Mantere, M. J., Cole, E., Warnecke, J., & Brandenburg, A. 2013 ApJ arXiv:1301.2595Google Scholar
Kemel, K., Brandenburg, A., Kleeorin, N., Mitra, D., & Rogachevskii, I. 2012 Solar Phys., 280 321 Google Scholar
Kleeorin, N. & Rogachevskii, I. 1994 Phys. Rev. E, 50 2716 CrossRefGoogle Scholar
Kleeorin, N., Mond, M. & Rogachevskii, I. 1996 A&A, 307 293 Google Scholar
Kosovichev, A. G. & Stenflo, J. O. 2008 ApJL, 688 L115 Google Scholar
Kosovichev, A. G. 2009 Spa. Sci. Rev., 144 175 Google Scholar
Krause, F. & Rädler, K.-H. 1980 MNRAS Mean-field Magnetohydrodynamics and Dynamo Theory Oxford: Pergamon Press Google Scholar
Lites, B. W. 2002 ApJ, 573 431 Google Scholar
Mitra, D., Candelaresi, S., Chatterjee, P., Tavakol, R., & Brandenburg, A. 2010 Astron. Nachr., 331 130 Google Scholar
Moffatt, H. K. 1961 J. Fluid Mech., 11 625 Google Scholar
Moffatt, H.K. 1978 MNRAS Magnetic Field Generation in Electrically Conducting Fluids Cambridge: Cambridge Univ. Press Google Scholar
Pinto, R. F., Brun, A. S., Jouve, L., & Grappin, R. 2011 ApJ, 737 72 Google Scholar
Pouquet, A., Frisch, U., & Léorat, J. 1976 J. Fluid Mech., 77 321 CrossRefGoogle Scholar
Racine, É., Charbonneau, P., Ghizaru, M., Bouchat, A., & Smolarkiewicz, P. K. 2011, ApJ 735, 46 Google Scholar
Rheinhardt, M. & Brandenburg, A. 2012 Astron. Nachr., 333 71 Google Scholar
Rogachevskii, I. & Kleeorin, N. 1997 Phys. Rev. E, 56 417 Google Scholar
Ruzmaikin, A. A. & Shukurov, A. M. 1982 Ap&SS, 82 397 Google Scholar
Saar, S. H. & Brandenburg, A. 1999 ApJ, 524 295 CrossRefGoogle Scholar
Schekochihin, A. A., Haugen, N. E. L., Brandenburg, A., Cowley, S. C., Maron, J. L., & McWilliams, J. C. 2005 ApJ, 625 L115 Google Scholar
Skumanich, A. 1972 ApJ, 171 565 Google Scholar
Stenflo, J. O. 2012 A&A, 547 A93 Google Scholar
Vögler, A. & Schüssler, M. 2007 A&A, 465 L43 Google Scholar
Warnecke, J. & Brandenburg, A. 2010 A&A, 523 A19 Google Scholar
Warnecke, J., Brandenburg, A., & Mitra, D. 2011 A&A, 534 A11 Google Scholar
Warnecke, J., Brandenburg, A., & Mitra, D. 2012 J. Spa. Weather Spa. Clim. 2 A11 Google Scholar
Warnecke, J., Käpylä, P. J., Mantere, M. J., & Brandenburg, A. 2013 ApJ arXiv:1301.2248Google Scholar