Abstract
We have examined the dynamics of the longitudinal magnetic field of active region NOAA 12673, using data from the Solar Dynamics Observatory (SDO). During the passage of the active region (AR) across the solar disk, its spots and background fields showed complex motion trajectories, and numerous small-scale short-lived local polarity inversion lines (LPILs) were formed when new magnetic fluxes appeared in the AR and came closer to fields of opposite polarity. The length of LPILs was less than 15.000 km (~20 arcsec); their lifetime was several hours. Study of the flare activity of NOAA 12673 has shown that low-power flares (optical class S, area ˂2 sq. degrees) generally occur near LPILs. Before small flares and the September 06, 2017 large flare (optical importance 3B, X-ray class X9.3), in limited sites of local and main polarity inversion lines there were shear stresses and an increase in the magnetic field gradient: in the region of low-power flares, to 1.3–1.5 G/km; in the region of the large flare, 3–3.5 G/km. The results obtained suggest that the longitudinal magnetic field behaves similarly before both small and large flares.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
