The Parker Solar Probe was launched on 2018 August 12 and completed its
second orbit on 2019 June 19 with perihelion of 35.7 solar radii. During this
time, the Energetic particle Instrument-Hi (EPI-Hi, one of the two energetic
particle instruments comprising the Integrated Science Investigation of the
Sun, ISOIS) measured seven proton intensity increases associated with stream
interaction regions (SIRs), two of which appear to be occurring in the same
region corotating with the Sun. The events are relatively weak, with observed
proton spectra extending to only a few MeV and lasting for a few days. The
proton spectra are best characterized by power laws with indices ranging from
-4.3 to -6.5, generally softer than events associated with SIRs observed at 1
au and beyond. Helium spectra were also obtained with similar indices, allowing
He/H abundance ratios to be calculated for each event. We find values of
0.016-0.031, which are consistent with ratios obtained previously for
corotating interaction region events with fast solar wind < 600 km s-1. Using
the observed solar wind data combined with solar wind simulations, we study the
solar wind structures associated with these events and identify additional
spacecraft near 1 au appropriately positioned to observe the same structures
after some corotation. Examination of the energetic particle observations from
these spacecraft yields two events that may correspond to the energetic
particle increases seen by EPI-Hi earlier.
