Authors: Kara L. Kniezewski (Air Force Institute of Technology), Seth H. Garland (Air Force Institute of Technology)

The solar storms in May of 2024 were some of the largest in two decades, capturing not only the attention of the solar science community, but that of the whole globe. NOAA Active Region (AR) 13664 hosted 11 X- and dozens of M-class flares, many of which were associated with the coronal mass ejections (CMEs) which consequently caused the severe geomagnetic storms here on Earth. Comparably, NOAA AR 12192 hosted 8 X- and dozens of M-class throughout its disk passage, but had no CMEs from flares originating in its core. With the striking similarities between these active regions in size, sunspot number, and flare productivity, but glaring differences in behavior, these two ARs provide an excellent opportunity to compare field structure of these ARs. We present initial results here of the time evolution of the coronal field for 5 flares in each AR by utilizing a non-linear force-free extrapolation (NLFFF). From the extrapolated field, we investigate for possible signatures of magnetic flux ropes and analyze the strength and decay of the external field which lies overhead, which can provide crucial information for whether a flare can hose a CME. In addition, we calculated other magnetic field parameters which have previously been consistent with eruptivity or confinement, such as the helicity, free energy, shear, decay index, and the potential and non-potential field strengths. This work ultimately can have useful implications for AR eruptivity and confinement mechanisms, as well as CME forecasting regimes.