Solar Grand Minima and Random Fluctuations in Dynamo Parameters

Moss, D. and Sokoloff, D. and Usoskin, I. and Tutubalin, V. (2008) Solar Grand Minima and Random Fluctuations in Dynamo Parameters. Solar Physics, 205. pp. 221-234. ISSN 0038-0938

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Abstract

Abstract We consider to what extent the long-term dynamics of cyclic solar activity in the form of Grand Minima can be associated with random fluctuations of the parameters governing the solar dynamo.We consider fluctuations of the alpha coefficient in the conventional Parker migratory dynamo, and also in slightly more sophisticated dynamo models, and demonstrate that they can mimic the gross features of the phenomenon of the occurrence of Grand Minima over suitable parameter ranges. The temporal distribution of these Grand Minima appears chaotic, with a more or less exponential waiting time distribution, typical of Poisson processes. In contrast, however, the available reconstruction of Grand Minima statistics based on cosmogenic isotope data demonstrates substantial deviations from this exponential law.We were unable to reproduce the non-Poissonic tail of the waiting time distribution either in the framework of a simple alpha-quenched Parker model or in its straightforward generalization, nor in simple models with feedback on the differential rotation. We suggest that the disagreement may only be apparent and is plausibly related to the limited observational data, and that the observations and results of numerical modeling can be consistent and represent physically similar dynamo regimes.

Item Type: Article
Uncontrolled Keywords: Magnetic fields · Sun: magnetic fields · Sun: activity · Stars: magnetic fields · Stars: late-type
Subjects: MSC 2010, the AMS's Mathematics Subject Classification > 85 Astronomy and astrophysics
PACS 2010, the AIP's Physics and Astronomy Classification Scheme > 90 GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS > 96 Solar System
PACS 2010, the AIP's Physics and Astronomy Classification Scheme > 90 GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS > 97 Stars
Depositing User: Ms Lucy van Russelt
Date Deposited: 06 Nov 2008
Last Modified: 20 Oct 2017 14:12
URI: http://eprints.maths.manchester.ac.uk/id/eprint/1169

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