FISM2-Eclipse: A full X/EUV irradiance model of solar eclipses

We developed a new model of solar irradiance that combines multi-wavelength eclipse masks from PyEclipse model with the high-rate FISM2 irradiance model. The combined FISM2-Eclipse model takes the masks to modify solar proxies used to initialize FISM2 at 1-minute temporal cadence, preserving the capability of capturing solar flares and spectral variability from FISM2 that incorporates the inherent wavelength-dependent nature of the solar eclipse occultations. FISM2-Eclipse was integrated into the GITM model and numerical experiments for the April 2024 total solar eclipse were performed. We quantify the importance of the full irradiance model in solar eclipse modeling of the IT system by comparing the model output difference between the full FISM2-Eclipse irradiance model, a single wavelength eclipse mask modified EUVAC, and we compare the results with a limited set of observations.