Parker Solar Probe Observations of Suprathermal and Energetic Particles during Orbits 18 and 19

Abstract The Parker Solar Probe Integrated Science Investigation of the Sun (IS⊙IS) instrument suite measured a variety of suprathermal and energetic particle events during orbits 18 and 19. We provide an overview of key features of the observations to provide guidance critical to making progress on complicated, integrated data sets like those provided by IS⊙IS. In this work, we analyze and describe observations of particle acceleration signatures associated with coronal mass ejection (CME)–driven shocks and solar flares from 2023 November to 2024 March as measured by the IS⊙IS/Energetic Particle Instrument-Low Energy and Energetic Particle Instrument-High Energy particle detectors. We present energy spectra for protons through Fe ions from ∼10 keV nuc −1 to >10 MeV nuc −1 , abundance ratios, and time series analyses for seven solar energetic particle (SEP) events with respect to the magnetic field and plasma context provided by the FIELDS and Solar Wind Electrons Alphas and Protons instruments, respectively. For SEP events in orbits 18 and 19, we find that acceleration driven by multiple CMEs in succession have larger variability in 4 He/H and Fe/O ratios than singular CMEs, that flare-associated SEP events preferentially accelerate higher mass-to-charge ratio particles, and that shock upstream transients may be present in CME-driven interplanetary shocks.