Speaker
Description
Solar energetic particle (SEP) events involving protons with energies exceeding 100 MeV are rare but significant phenomena in the context of space weather. We present a new catalogue of such events measured by SOHO/ERNE and EPHIN covering the last 30 years. It includes detailed information on proton fluxes and associated solar sources, such as soft and hard X-ray flares, coronal mass ejection (CME) parameters, type II and III radio bursts, and more. This dataset enables a global analysis of the characteristics of these extreme solar events and their solar origin. The first results are promising and, combined with other studies of high-energy SEP events, offer new insights into the acceleration scenarios and origins of these extreme events.
It also provides a starting point for more detailed studies, such as the Ground-Level Enhancement (GLE) event of May 11, 2024 (GLE74), which followed a significant Forbush decrease and was associated with an X5.8 flare and a fast CME exceeding 1500 km/s. This event was detected both at the Lagrange L1 point and by the Solar-Terrestrial Relations Observatory Ahead (STEREO-A). We used 3D reconstruction techniques and magnetohydrodynamic modelling to characterise the coronal shock wave and obtain the evolution of shock parameters along the connected magnetic field lines. This procedure will be reproduced for other events in order to include these parameters in the catalogue, as an additional resource for understanding the various acceleration conditions of very high-energy SEP events.
This work is part of the Horizon Europe SPEARHEAD project.
