Dynamo models of grand minima

Choudhuri, Arnab Rai (2012) Dynamo models of grand minima. In: 286th Symposium of the International-Astronomical-Union, OCT 03-07, 2011, Mendoza, ARGENTINA, pp. 350-359.

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Abstract

Since a universally accepted dynamo model of grand minima does not exist at the present time, we concentrate on the physical processes which may be behind the grand minima. After summarizing the relevant observational data, we make the point that, while the usual sources of irregularities of solar cycles may be sufficient to cause a grand minimum, the solar dynamo has to operate somewhat differently from the normal to bring the Sun out of the grand minimum. We then consider three possible sources of irregularities in the solar dynamo: (i) nonlinear effects; (ii) fluctuations in the poloidal field generation process; (iii) fluctuations in the meridional circulation. We conclude that (i) is unlikely to be the cause behind grand minima, but a combination of (ii) and (iii) may cause them. If fluctuations make the poloidal field fall much below the average or make the meridional circulation significantly weaker, then the Sun may be pushed into a grand minimum.

Item Type:	Conference Proceedings
Series.:	IAU Symposium Proceedings Series
Publisher:	Cambridge University Press
Additional Information:	Copyright of this article belongs to Cambridge University Press.
Keywords:	Sun: Dynamo; Sun: Activity; Sunspots
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	28 Feb 2013 08:50
Last Modified:	04 Mar 2013 08:41
URI:	http://eprints.iisc.ac.in/id/eprint/45354

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