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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We present high-resolution and multi-line observations of a C2-class solarflare, occurred in NOAA AR 12740 on May 6, 2019. The rise, peak and decayphases of the flare were recorded continuously and quasi-simultaneously in theCa II K line with the CHROMIS instrument, the Ca II 8542 and Fe I 6173 \AAlines with the CRISP instrument at the SST. The observations in thechromospheric Ca II lines exhibit intense brightening near the flarefootpoints. At these locations, a non-LTE inversion code was employed to inferthe temperature, magnetic field, line-of-sight (LOS) velocity andmicroturbulent velocity stratification in the flaring atmosphere. During theflare peak time, the LOS velocity shows both upflows and downflows around theflare footpoints in the upper chromosphere and lower chromosphere,respectively. Moreover, the temporal analysis of the LOS magnetic field at theflarepoints exhibits a maximum change of ~600 G. After the flare, the LOSmagnetic field decreases to the non-flaring value, exhibiting no permanent orstep-wise change. The analysis of response functions to the temperature, LOSmagnetic field and velocity shows that the Ca II lines exhibit enhancedsensitivity to the deeper layers (i.e., log_t ~ -3) of the flaring atmosphere,whereas for the non-flaring atmosphere they are mainly sensitive around log_t ~-4. We suggest that a fraction of the apparent increase in the LOS magneticfield at the flare footpoints may be due to the increase in the sensitivity ofthe Ca II 8542 \AA line in the deeper layers, where the field strength isrelatively stronger. The rest can be due to magnetic field reconfigurationduring the flare. Our observations illustrate that even a less intense C-classflare can heat the deeper layers of the solar chromosphere, mainly at the flarefootpoints, without affecting the photosphere.

Stratification of physical parameters in a C-class solar flare using multi-line observations