Modeling collisionless heliospheric shocks observed in the inner heliosphere

Heliospheric shocks connected with ICMEs (interplanetary coronal mass ejections) were detected by many spacecrafts in the past, such as Wind, DSCOVR, and STEREO at ~1AU. Recently, the Parker Solar Probe has detected for the first time high Mach number shock on Sept 5, 2022 in the inner heliosphere close to the Sun at ~0.07AU with Alfvenic Mach number M_A ≈2.5, and θ_Bn~50^o, the angle between the shock normal and the upstream magnetic field. We investigate the magnetic field structure and characteristics of the ion VDFs, as well as the kinetic waves downstream of the shocks using 2.5D hybrid kinetic model. We find that the protons and alpha particle populations velocity distributions (VDFs) are significantly affected by the shock in the downstream region. We evaluate the impact of the shock parameters and of alpha particle relative abundance on the downstream magnetic and density oscillations. The model shows that the PSP shock was subject to corrugation instability, leading to local variability of the shock front normal angle with the upstream magnetic field. We extend the model to investigate the proton alpha particle temperature anisotropies on the shock properties, using typical values of ion anisotropies observed by PSP. We investigate the effects of the ion kinetic properties on the oblique high Mach number shock structures and discuss how the modeling results can improve the interpretation of spacecraft observations of collisionless heliospheric shocks.