Identifying Magnetic Energy "Hot Spots" in the Corona

Observations of the magnetic surface flux in the Earth-facing side of the photosphere are regular but lack a global perspective. As we extend farther out into the corona, measurements of the magnetic field have recently become available, although with a narrow field of view. Therefore, we rely on models to get the solar exterior global field of view. While current models can extrapolate the magnetic field from surface flux observations assuming a current-free corona, other techniques are used to simulate the current-carrying field via flux transport methods and inserting current-carrying fields like twisted flux ropes into the corona. These current-carrying fields are of interest for studying solar energetic events like coronal mass ejections and flares because they provide the energy reservoir needed to drive these events. Previous studies suggest that ground-based polarimetric measurements correlate with the energy of the current-carrying field. In this study we generated synthetic polarimetric observations from a fully-resolved magnetohydrodynamics model of the August 21, 2017 eclipse. The synthetic observations were used as input to a diagnostic we developed to identify regions where the modeling team inserted twisted flux ropes. The diagnostic evaluated linearly and circularly polarized synthetic observations of the corona as a means to identify the current-carrying magnetic energy density. We found that the diagnostic does identify the distribution of flux ropes in the corona. Thus, our findings motivate the implementation of polarimetric measurements to identify “hot spots” in which we can insert flux ropes and a degree of the twist/shear in the current-carrying field.