With this three-year SHINE project, the PI aims to investigate the relationship between global disturbances from the solar corona and the angular spread of Solar Energetic Particle (SEP) events, in order to advance present understanding of when, where and how these particles are accelerated and released. The project team examine Extreme Ultra Violet (EUV) images taken by SDO and STEREO in comparison with coronagraph data from STEREO and SOHO to trace the global coronal disturbances into coronal mass ejections (CMEs) and associated shock waves. For 20 to 30 near-relativistic electron events (with and without large angular spread), the team will look for significant differences in the properties of global coronal disturbances and lack thereof. The team will compare the observed onset times of electron events at STEREO and near the Earth with the times at which the global coronal disturbances and CME-driven shocks intersect field lines connecting to observers at the respective spacecraft. The SEP onsets can also be influenced by the interplanetary magnetic field, which may deviate from the Parker spiral. The team will analyze solar wind data from STEREO, near the Earth, and at other locations in the inner heliosphere, to estimate the effective path length the particles experience and additionally to understand the origin of non-Parker-spiral field. The research agenda is supplemented by running heliospheric simulations at the Community Coordinated Modeling Center (CCMC) with customized boundary conditions to probe macroscopic disturbances in solar wind. Furthermore, the team will investigate the associated SEP ion data in perspective to address the distinction between impulsive and gradual SEP events in terms of the processes near the Sun and in the interplanetary space.
The project team aims to improve present understanding of SEP events by adopting a cross-disciplinary approach that addresses both solar and interplanetary in-situ data as important elements, and includes numerical simulations. This project has the potential of changing the prevalent view of the origins of SEP events in a major way, and thus eventually give societal benefit of correctly predicting SEP events. The team will disseminate the project results at various meetings including SHINE workshops, in refereed journals, and through the Heliophysics Event Knowledge-base developed at the PI's institution. The research agenda of this project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research.
