English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The photospheric response to solar flares, also known as coronal backreaction, is often observed as sudden flare-induced changes in vector magneticfield and sunspot motions. However, it remains obscure whether evolving flareribbons, the flare signature closest to the photosphere, are accompanied bychanges in vector magnetic field therein. Here we explore the relationshipbetween the dynamics of flare ribbons in the chromosphere and variations ofmagnetic fields in the underlying photosphere, using high-resolution off-bandH-alpha images and near-infrared vector magnetograms of the M6.5 flare on 2015June 22 observed with the 1.6 m Goode Solar Telescope. We find that changes ofphotospheric fields occur at the arrival of the flare ribbon front, thuspropagating analogously to flare ribbons. In general, the horizontal fieldincreases and the field lines become more inclined to the surface. When ribbonssweep through regions that undergo a rotational motion, the fields transientlyturn more vertical with decreased horizontal field and inclination angle, andthen restore and/or become more horizontal than before the ribbon arrival. Theribbon propagation decelerates near the sunspot rotation center, where thevertical field becomes permanently enhanced. Similar magnetic field changes arediscernible in magnetograms from the Helioseismic and Magnetic Imager (HMI),and an inward collapse of coronal magnetic fields is inferred from the timesequence of non-linear force-free field models extrapolated from HMImagnetograms. We conclude that photospheric fields respond nearlyinstantaneously to magnetic reconnection in the corona.

Evolution of Photospheric Vector Magnetic Field Associated with Moving Flare Ribbons As Seen By GST