TY - JOUR
T1 - Solar active region flux fragmentation, subphotospheric flows, and flaring
AU - Canfield, Richard C.
AU - Russell, Alexander J.B.
PY - 2007/6/10
Y1 - 2007/6/10
N2 - 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.
AB - 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.
KW - Sun: flares
KW - Sun: helioseismology
KW - Sun: magnetic fields
UR - http://www.scopus.com/inward/record.url?scp=34250846956&partnerID=8YFLogxK
U2 - 10.1086/519215
DO - 10.1086/519215
M3 - Article
AN - SCOPUS:34250846956
SN - 0004-637X
VL - 662
SP - L39-L42
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1 II
ER -