Solar Energetic Particles in Solar Cycle #25: Observations and Comparisons with Previous Cycles

As Solar Cycle #25 reaches its peak of activity, Solar Orbiter is observing a substantial increase in solar flares, coronal mass ejections (CMEs), and solar energetic particles (SEPs). Specifically, the Energetic Particle Detector (EPD) on board Solar Orbiter has been tracking and characterizing the rise in SEP activity over the past five years. This paper focuses on the intensities of suprathermal and energetic particles from 2020 through 2025. Both electrons, ions, and ³He particles show a notable increase, which aligns closely with other solar phenomena. We compare the SEP flux observed during this cycle with the measurements from Cycles #23 and #24, as recorded by ACE. The results reveal that the flux levels in Cycle #25 are significantly higher than those of Cycle #24, and comparable to those observed during Cycle #23. This surge in solar activity is filling the heliosphere with high-energy SEP particles, which are influencing the entire solar system, including Earth.