Responses of energetic electrons to the interplanetary shock waves detected in 2024 with Solar Orbiter

     High-energy electrons in the heliosphere are significantly influenced by irregularities in the solar wind and interplanetary magnetic field. One of the most powerful and actively studied irregularities are interplanetary (IP) shocks. We used data from Solar Orbiter’s Solar Wind Analyser (SWA) and magnetometer (MAG), and the method developed by Yakovlev et al. (2025) to determine the relevant shock parameters. We identified 69 IP shocks which occurred at varying distances from the Sun.

      To demonstrate the variability in acceleration, dissipation, and absence of response of high-energy electrons across selected narrow energy bands, we analyzed data derived from the Suprathermal Telescope of Electrons and Protons (STEP), the Electron and Proton Telescope (EPT, Sun direction), and the High Energy Telescope (HET, Sun direction) of the Energetic Particle Detector (EPD) suite onboard Solar Orbiter. For a quick-look analysis, we demonstrate light curves of particle fluxes in a few energy ranges in the upstream/foreshock and downstream/aftershock regions.

     We also present selected parameters of the IP shock wave, including IP shock types (FF, SR, SF, FR), magnetic and gas compression factors, plasma beta parameters, shock angles, Alfvenic and magnetosonic Mach numbers, as well as Alfvenic and shock speeds.

     This work is supported by the “Long-term program of support of the Ukrainian research teams at the Polish Academy of Sciences, carried out in collaboration with the U.S. National Academy of Sciences, with the financial support of external partners”.

1. O. Yakovlev, O. Dudnik, A. Wawrzaszek. Statistical analysis of interplanetary shock waves measured by a Solar Wind Analyzer and a magnetometer onboard the Solar Orbiter Mission in 2023. Journal of Space Weather and Space Climate. 2025, 15, 32. https://doi.org/10.1051/swsc/2025027