Reconnecting flux-rope dynamo

Baggaley, A.W., Barenghi, C.F., Shukurov, A. and Subramanian, K. (2009) Reconnecting flux-rope dynamo. Physical Review E, 80(5), 055301. (doi: 10.1103/PhysRevE.80.055301)

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Abstract

We develop a model of the fluctuation dynamo in which the magnetic field is confined to thin flux ropes advected by a multiscale model of turbulence. Magnetic dissipation occurs only via reconnection of the flux ropes. This model can be viewed as an implementation of the asymptotic limit Rm→∞ for a continuous magnetic field, where magnetic dissipation is strongly localized to small regions of strong-field gradients. We investigate the kinetic-energy release into heat mediated by the dynamo action, both in our model and by solving the induction equation with the same flow. We find that a flux-rope dynamo is an order of magnitude more efficient at converting mechanical energy into heat. The probability density of the magnetic energy release in reconnections has a power-law form with the slope −3, consistent with the solar corona heating by nanoflares.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Baggaley, Dr Andrew
Authors: Baggaley, A.W., Barenghi, C.F., Shukurov, A., and Subramanian, K.
College/School:College of Science and Engineering > School of Mathematics and Statistics > Mathematics
Journal Name:Physical Review E
Publisher:American Physical Society
ISSN:1539-3755

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