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Cycles and cycle modulations

Published online by Cambridge University Press:  05 July 2012

Axel Brandenburg
Affiliation:
Nordita, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden email: [email protected] Department of Astronomy, Stockholm University, SE-10691 Stockholm, Sweden
Gustavo Guerrero
Affiliation:
Nordita, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden email: [email protected] Solar Physics, HEPL, Stanford University, Stanford, CA 94305-4085, USA
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Abstract

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Some selected concepts of the solar activity cycle are reviewed. Cycle modulations through a stochastic α effect are being identified with limited scale separation ratios. Three-dimensional turbulence simulations with helicity and shear are compared at two different scale separation ratios. In both cases the level of fluctuations shows relatively little variation with the dynamo cycle. Prospects for a shallow origin of sunspots are discussed in terms of the negative effective magnetic pressure instability. Tilt angles of bipolar active regions are discussed as a consequence of shear rather than the Coriolis force.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2012

References

Blackman, E. G. & Brandenburg, A. 2002, ApJ, 579, 359CrossRefGoogle Scholar
Brandenburg, A. 2005, ApJ, 625, 539Google Scholar
Brandenburg, A. & Käpylä, P. J. 2007, New J. Phys., 9, 305, 1Google Scholar
Brandenburg, A., Kemel, K., Kleeorin, N., Mitra, D., & Rogachevskii, I. 2011, ApJ, 740, L50CrossRefGoogle Scholar
Brandenburg, A., Kemel, K., Kleeorin, N., & Rogachevskii, I. 2012, ApJ, 749, 179Google Scholar
Brandenburg, A., Kleeorin, N., & Rogachevskii, I. 2010, Astron. Nachr., 331, 5Google Scholar
Brandenburg, A., Rädler, K.-H., & Kemel, K. 2012, A&A, 539, A35Google Scholar
Brandenburg, A., Rädler, K.-H., Rheinhardt, M., & Käpylä, P. J. 2008, ApJ, 676, 740Google Scholar
Brandenburg, A. & Spiegel, E. A. 2008, Astron. Nachr., 329, 351CrossRefGoogle Scholar
Brandenburg, A. & Subramanian, K. 2005, Phys. Rep., 417, 1Google Scholar
Brandenburg, A., Subramanian, K., Balogh, A., & Goldstein, M. L. 2011, ApJ, 734, 9CrossRefGoogle Scholar
Cally, P. S., Dikpati, M., & Gilman, P. A. 2003, ApJ, 582, 1190CrossRefGoogle Scholar
Chatterjee, P. & Choudhuri, A. R. 2006, Solar Phys., 239, 29Google Scholar
Choudhuri, A. R. 1992, A&A, 253, 277Google Scholar
Choudhuri, A. R., Schüssler, M., & Dikpati, M. 1995, A&A, 303, L29Google Scholar
Dikpati, M. & Charbonneau, P. 1999, ApJ, 518, 508Google Scholar
D'Silva, S. & Choudhuri, A. R. 1993, A&A, 272, 621Google Scholar
Gilman, P. A. & Dikpati, M. 2000, ApJ, 528, 552Google Scholar
Guerrero, G. & de Gouveia Dal Pino, E. M. 2008, A&A, 485, 267Google Scholar
Ilonidis, S., Zhao, J., & Kosovichev, A. 2011, Science, 333, 993CrossRefGoogle Scholar
Käpylä, P. J., Brandenburg, A., Kleeorin, N., Mantere, M. J., & Rogachevskii, I. 2012, MNRAS, 2465Google Scholar
Käpylä, P. J. & Brandenburg, A. 2009, ApJ, 699, 1059CrossRefGoogle Scholar
Kemel, K., Brandenburg, A., Kleeorin, N., & Rogachevskii, I. 2012, Astron. Nachr., 333, 95Google Scholar
Kitchatinov, L. L. & Mazur, M. V. 2000, Solar Phys., 191, 325CrossRefGoogle Scholar
Kleeorin, N., Mond, M., & Rogachevskii, I. 1996, A&A, 307, 293Google Scholar
Kleeorin, N. & Rogachevskii, I. 1994, Phys. Rev. E, 50, 2716CrossRefGoogle Scholar
Kleeorin, N. I., Rogachevskii, I. V., & Ruzmaikin, A. A. 1990, Sov. Phys. JETP, 70, 878Google Scholar
Kosovichev, A. G., & Stenflo, J. O. 2008, ApJ, 688, L115CrossRefGoogle Scholar
Moss, D., Brandenburg, A., Tavakol, R. K., & Tuominen, I. 1992, A&A, 265, 843Google Scholar
Nandy, D., Muñoz-Jaramillo, A., & Martens, P. C. H. 2011, Nature, 471, 80CrossRefGoogle Scholar
Parfrey, K. P. & Menou, K. 2007, ApJ, 667, L207Google Scholar
Rogachevskii, I. & Kleeorin, N. 2007, Phys. Rev. E, 76, 056307CrossRefGoogle Scholar
Ruzmaikin, A. A. 1981, Comments Astrophys., 9, 85Google Scholar
Schmitt, D., Schüssler, M., & Ferriz-Mas, A. 1996, A&A, 311, L1Google Scholar
Sur, S., Brandenburg, A., & Subramanian, K. 2008, MNRAS, 385, L15CrossRefGoogle Scholar
Tavakol, R. K. 1978, Nature, 276, 802CrossRefGoogle Scholar
Warnecke, J., Brandenburg, A., & Mitra, D. 2011, A&A, 534, A11Google Scholar
Weiss, N. O., Cattaneo, F., Jones, C. A. 1984, Geophys. Astrophys. Fluid Dyn., 30, 305Google Scholar
Yoshimura, H. 1972, ApJ, 178, 863Google Scholar