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Oscillatory migratory large-scale fields in mean-field and direct simulations

Published online by Cambridge University Press:  26 February 2010

Dhrubaditya Mitra
Affiliation:
Astronomy Unit, School of Mathematical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK emails: [email protected]; [email protected]
Reza Tavakol
Affiliation:
Astronomy Unit, School of Mathematical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK emails: [email protected]; [email protected]
Axel Brandenburg
Affiliation:
NORDITA, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden email: [email protected] Department of Astronomy, Stockholm University, SE 10691 Stockholm, Sweden
Petri J. Käpylä
Affiliation:
NORDITA, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden email: [email protected] Observatory, Tähtitorninmäki (PO Box 14), FI-00014, University of Helsinki, Finland email: [email protected]
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Abstract

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We summarise recent results form direct numerical simulations of both non-rotating helically forced and rotating convection driven MHD equations in spherical wedge-shape domains. In the former, using perfect-conductor boundary conditions along the latitudinal boundaries we observe oscillations, polarity reversals and equatorward migration of the large-scale magnetic fields. In the latter we obtain angular velocity with cylindrical contours and large-scale magnetic field which shows oscillations, polarity reversals but poleward migration. The occurrence of these behviours in direct numerical simulations is clearly of interest. However the present models as they stand are not directly applicable to the solar dynamo problem. Nevertheless, they provide general insights into the operation of turbulent dynamos.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2010

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