Association of solar flares with twisting of magnetic neutral lines

Abstract

A 'twisting index' is defined, assuming that flares tend to occur in highly sheared magnetic fields which also lead to a twisting of magnetic neutral lines in complex active regions. The correlation of this twisting index with flares of various importance classes has been investigated. For cases where at least one bright flare has occurred in the complex active region, the number of flare events seems to increase with the twisting index. For the cases of at least one normal flare or all faint flares, a similar but weaker dependence is noted