Abstract Details


Name: Anjan Banerjee
Affiliation: Department of Physics, Indian Institute of Science, Bangalore, India
Conference ID: TVS202510113
Title: SOLAR FLARE PREDICTION USING NONLINEAR FORCE-FREE MODEL
Authors and Co-Authors: Anjan Banerjee
Abstract Type: Contributory Presentation
Abstract: The Sun’s coronal magnetic field plays the central role in driving dynamic solar phenomena such as flares and coronal mass ejections. The magnetic field distribution in these eruptive coronal struc- tures often store excess magnetic energy than their minimum potential state thus expected to have non vanishing current. Since direct continuous measurements of the coronal magnetic field are not available, extrapolation techniques based on photospheric magnetograms are used by the commu- nity. This study investigates the dynamic evolution of the magnetic field in a flaring active region by reconstructing the associated three-dimensional coronal magnetic field using photosphere vec- tor magnetogram data under the force-free field assumption. We solve the nonlinear force-free field (NLFFF) equations, where magnetic forces dominate plasma dynamics in the corona. A boundary-weighting scheme is implemented, allowing the model to depend solely on the observed photospheric data. Further to improve accuracy, the in- put magnetogram is preprocessed to reduce measurement noise and ensure consistency with the force-free condition. The method is first validated using a known semi-analytical force-free solution. It is then applied to observed photospheric magnetic field data, with robustness assessed by analyzing the angle between the magnetic field and electric current, as well as the zero divergence condition of the magnetic field across the computational grid. We also track the evolution of the maximum current and magnetic energy over time for the flaring active region to investigate the presence of threshold triggering the eruption. Overall, this optimization-based approach, combined with data preprocessing, provides a reli- able means of studying the Sun’s magnetic field in three dimensions and gaining insights into solar eruptive events such as flares and eruptions.