Authors: Sushree S Nayak (CSPAR, UAH, Huntsville, AL), Qiang Hu (CSPAR, & Dept. of Space Science, UAH, Huntsville, AL)

A solar flare is one of the most explosive phenomena in the solar atmosphere. Magnetic reconnection is believed to be the major cause behind this energetic phenomenon which explains the process of energy released. However, the onset, ongoing mechanism during the flaring process, and afterward impact on the surrounding atmosphere are still not fully understood. Here, we have studied one eruptive flare to understand the onset and the physical properties of magnetic reconnection. We investigated the M1.1 flare on May 23, 2021, hosted by NOAA AR 12824 using a data-constrained MHD simulation initialized with a novel non-force-free-field (NFFF) extrapolation model. In the extrapolated field, we found one flux rope, a three-dimensional magnetic null point, and a set of sheared arcade-type field lines arching over the flaring region. We then performed an MHD simulation using the EULAG-MHD (Eulag/semi-Lagrangian fluid solver) model to understand the evolution of different topologies during the flaring activity with an open and line-tied boundary condition utilizing the NFFF extrapolated field as the initial condition. Notable is their remarkable correspondence to the observational features seen in multiwavelength channels of AIA/SDO. Additionally, we estimated the reconnection flux using the flare ribbons from observations. A similar approach is adopted in the time-dependent evolution, where we have calculated the fluxes using a set of sample field lines passing through the ribbon area. Interesting is their quantitative agreement with each other in terms of the order during the flare. Within the scope of the simulation, we have attempted to calculate the (approximated) reconnection rate during the flaring process using the sample field lines used for the estimation of reconnection fluxes.