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Threshold of measures of active regions and solar activities. Yang Liu – Stanford University yliu@solar.stanford.edu. Results for the entire solar cycle 23 / SoHO MDI. X-flaring ARs. |(dH m / dt)| > 6 x 10 36 Mx 2 s -1. LaBonte et al. (2006). 08/13. Durham, 06/27/06.
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Threshold of measures of active regions and solar activities Yang Liu – Stanford University yliu@solar.stanford.edu
Results for the entire solar cycle 23 / SoHO MDI X-flaring ARs |(dHm / dt)| > 6 x 1036 Mx2 s-1 LaBonte et al. (2006) 08/13 Durham, 06/27/06 This slit is from M. Georgoulis’ presentation made in 2006 SPD. X-flaring ARs appear to to have a lower threshold in their peak helicity rates
Sufficient statistics needed Relative magnetic free energy |Hm| (x 10 42 Mx 2) • Eruptive active regions: • |Hm| > 10 43 Mx 2 • (Efree/Etot) > 0.10 • Non-eruptive active regions: • |Hm| < 10 43 Mx 2 • (Efree/Etot) < 0.05 12/13 Durham, 06/27/06 This slit is from M. Georgoulis’ presentation made in 2006 SPD.
Flare productivity index is defined as: p(x)=s(x)/t(x), where s is the number of active regions with a measure greater than x, while t is total number. Flare productivity vs magnetic gradient Flare productivity vs length of neutral line Flare productivity vs number of singular points From Cui et al (2006)