ISEP

The ISEPIntegrated Solar Energetic Proton Alert/Warning System project is a collaborative effort between SRAGSpace Radiation Analysis Group and the CCMCCommunity Coordinated Modeling Center to aid in transitioning SEPSolar Energetic Proton prediction models from research to operations in preparation for exo- LEOLow Earth Orbit missions such as Artemis. With SRAGSpace Radiation Analysis Group console operators as the end user, the project focuses on models that help answer the three main questions listed in the Motivation section.

During the first year of the ISEPIntegrated Solar Energetic Proton Alert/Warning System project, six models were selected. These models include:

• MAG4
• SEPSTER
• UMASEP
• REleASE
• SEPMOD
• STAT

MAG4 is a probabilistic model that forecasts the occurrence of M+X-class flares, X-class flares, CMEsCoronal Mass Ejections, fast CMEsCoronal Mass Ejections, and SPEsSolar Proton Events. Predictions are made by using a derived relation between free energy proxies of active region neutral lines and the likelihood of event occurrence.

SEPSTER is a deterministic, empirical model that predicts the peak flux of 14-24 MeVMega Electron Volt protons at 1 AUAstronomical Unit. Predictions are made based on an empirically-derived equation that relates the intensity of SEPsSolar Energetic Protons to the speed of the associated CMECoronal Mass Ejection and the longitudinal distance between the source location of associated solar event and the footpoint at the Sun of the magnetic field line connecting to the observer.

UMASEP is a deterministic, empirical model that predicts the maximum proton flux within several hours following X-ray observations from flaring. The prediction is based off the slope of the X-ray flux and the magnetic connectivity of Earth to the Sun.

REleASE is a deterministic, empirical model that predicts proton flux based on a derived empirical relation between proton flux and the rise of electron flux. Since electrons typically accompany protons and arrive first during SPEsSolar Proton Events, this model can predict protons with 30-90 minutes of advanced warning time.

SEPMOD is a deterministic, physics model that predicts the time profile of SEPsSolar Energetic Protons at 1 AUAstronomical Unit. It is a model of the propagation of particles accelerated at CMECoronal Mass Ejection shocks and propagated along the magnetic field lines connected to Earth. CMEsCoronal Mass Ejections are modeled within SEPMOD by a coupled MHDMagneto-hydro-dynamic model such as Enlil.

STAT is a deterministic, physics model that predicts the time profile of SEPsSolar Energetic Protons at 1 AUAstronomical Unit. It is the coupling of the MHDMagneto-hydro-dynamic model, CORHEL/MAS, and the particle transport model, EPREM.

ISEPIntegrated Solar Energetic Proton Alert/Warning System is persuing two additional projects: one with GSUGeorgia State University and the other with SWRISouthwest Research Institute. The GSUGeorgia State University work involves using machine learning to create an all-clear forecast of SPEsSolar Particle Events. The SWRISouthwest Research Institute work involves using multi-spacecraft observations to determine a realistic seed population spectrum at 0.1 AUAstronomical Unit that can be used in physics-based models such as SEPMOD and STAT.