Electric-Current Neutralization, Magnetic Shear, and Eruptive Activity in Solar Active Regions

TL;DR

This study explores how electric-current neutralization and magnetic shear in solar active regions relate to their likelihood of producing flares and CMEs, finding non-neutralized currents are linked to eruptive activity.

Contribution

It demonstrates that non-neutralized electric currents in active regions are better indicators of CME potential than magnetic shear alone.

Findings

CME-producing ARs have strongly non-neutralized currents.

Non-neutralized currents are better predictors of eruptive activity.

Magnetic shear differences are less significant than current neutralization.

Abstract

The physical conditions that determine whether or not solar active regions (ARs) produce strong flares and coronal mass ejections (CMEs) are not yet well understood. Here we investigate the association between electric-current neutralization, magnetic shear along polarity inversion lines (PILs), and eruptive activity in four ARs; two emerging and two well-developed ones. We find that the CME-producing ARs are characterized by a strongly non-neutralized total current, while the total current in the ARs that did not produce CMEs is almost perfectly neutralized. The difference in the PIL-shear between these two groups is much less pronounced, which suggests that the degree of current-neutralization may serve as a better proxy for assessing the ability of ARs to produce CMEs.