Solar active region flux fragmentation, subphotospheric flows, and flaring

Canfield, R.C. and Russell, A.J.B. (2007) Solar active region flux fragmentation, subphotospheric flows, and flaring. Astrophysical Journal, 662(1), L39-L42. (doi: 10.1086/519215)

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Publisher's URL: http://dx.doi.org/10.1086/519215

Abstract

We explore the properties of the fragmentation of magnetic flux in solar active regions. We apply gradient-based tessellation to magnetograms of 59 active regions to identify flux fragments. First, we find that the distribution function of flux fragments in these regions is highly consistent with lognormal form, which is the most direct evidence yet obtained that repeated random bifurcation dominates fragmentation and coalescence in all active regions. Second, we apply nonparametric statistical methods to the variance of the lognormal distribution of fragment flux, the flare X-ray energy output of the active regions, and kinetic helicity measurements in the upper convection zone to show that there is no significant statistical relationship between the amount of fragmentation of an active region's flux at photospheric levels and the amplitude of either its average kinetic helicity density in the upper convection zone or its X-ray flare energy output.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Russell, Dr Alexander
Authors: Canfield, R.C., and Russell, A.J.B.
College/School:College of Science and Engineering > School of Physics and Astronomy
Journal Name:Astrophysical Journal
ISSN:0004-637X
ISSN (Online):1538-4357

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