Speaker
Description
First Name: George
Last Name: Ho
Email Address: george.ho@swri.org
Affiliation: Southwest Research Institute
All Authors: George C. Ho, Glenn M. Mason, Robert C. Allen, Samuel T. Hart, Athanasios Kouloumvakos, Robert F. Wimmer-Schweingruber, Javier Rodríguez-Pacheco, Raúl Gómez-Herrero
Abstract: Solar Orbiter began its high-latitude phase following a Venus gravity assist on February 18, 2025, reaching a maximum heliographic latitude of ~17° relative to the solar equator. A key objective of the mission is to investigate the physical processes governing Solar Energetic Particle (SEP) events, particularly the acceleration and transport of particles in the inner heliosphere. The Energetic Particle Detector (EPD) onboard Solar Orbiter has continuously monitored SEP activity over the past five years, including throughout this recent high-latitude phase. This study focuses on SEP events observed during 2025 while the spacecraft was at elevated latitudes. Beginning in March, EPD detected multiple SEP events, including several ³He-rich impulsive events and a few large, CME-associated events. Using a magnetic connectivity tool, we calculated the magnetic footpoints of Solar Orbiter on the solar surface to evaluate source-region connections. These observations help assess whether SEP propagation depends solely on the angular separation between source and observer in either longitude or latitude, or if it also reflects influences macroscale structures, such as proximity to the heliospheric current sheet or other large-scale solar structures.