Authors: Abdullah Shmies (The University of Texas at San Antonio), Maher A. Dayeh (Southwest Research Institute), Radoslav Bucik (Southwest Research Institute), Samuel T. Hart (The University of Texas at San Antonio)

Solar Energetic particle (SEP) events are phenomena characterized by the acceleration of particles to high energies in interplanetary space. Ground level enhancement (GLE) events are extreme SEP occurrences reaching energies up to hundreds of MeVs, detectable on Earth by Neutron Monitors. Understanding GLE formation processes is crucial for mitigating radiation risks to human space assets.

In this study, we perform a thorough timing analysis on a large set of GLE events from the worldwide Neutron Monitor Database (NMDB). We infer the particle release time at the Sun using velocity dispersion analysis from multiple near-Earth spacecraft. We then perform a comparative analysis between the particle release times and the onset times of the associated X-ray and gamma-ray emissions (when available) to assess the contribution of solar flares to GLEs.