Authors: Maria D. Kazachenko, Yuhong Fan, Andrei Afanasev

The standard flare model suggests an idealized view of quadrupolar topology and evolution of coronal magnetic fields during flares. However, data-driven MHD simulations and thousands of observed solar flares suggest that fields in solar eruptions are far more complex. Here we combine state-of-the-art data-driven MHD simulation of the flaring active region NOAA 11158 (Fan et al. 2024) and ribbons/dimming observations with a goal of realistic description of coronal magnetic field dynamics during the flare. For the analysis of the 3D coronal magnetic-fields evolution we introduce a new method called “L-maps”. We show how to use these L-maps to identify ribbons and coronal dimming in simulations. We then compare these simulated ribbons and coronal dimmings with observations, finding many similarities in their morphology, and thus validating our simulated coronal magnetic field evolution. We then use the validated L-maps to derive clusters of coronal magnetic field evolution using K-means clustering. Our detailed analysis allows us to distinguish four stages of coronal magnetic field evolution during the flare and make several important findings which we describe in this work.