Latitudinal Variability of Stream Interactions Regions: Multi-spacecraft Comparisons with Solar Orbiter

Stream interaction regions (SIRs) are formed where high-speed streams from coronal holes expand into slower preceding solar wind. Simulations have long shown significant latitudinal structuring to SIRs and their associated energetic populations, which have been additionally suggested from high-latitude Ulysses observations. However, multi-point observations of SIRs from observers at different latitudes are needed to constrain this variability. This includes better understanding the role of coronal hole properties and impacts of latitudinal variability in the preceding slow solar wind streams on the evolution of SIR structures. In this presentation, we focus on recent off-ecliptic Solar Orbiter observations in comparison with observations at ACE and STEREO-A to further explore the importance of latitudinal structuring of SIRs and associated energetic particles.