2023/11/19 by D. B. Graham, Y. V. Khotyaintsev, Graham, D. B. +11 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Earthquake Detection and Analysis #FOS: Physical sciences #Ionosphere and magnetosphere dynamics #Plasma Physics (physics.plasm-ph) #Solar and Space Plasma Dynamics #Space Physics (physics.space-ph)
paper · pdf · doi:10.48550/arxiv.2311.11373
openalex publication_date 2023/11/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
A thorough understanding of collisionless shocks requires knowledge of how different ion species are accelerated across the shock. We investigate a bow shock crossing using the Magnetospheric Multiscale spacecraft after a coronal mass ejection crossed Earth, which led to solar wind consisting of protons, alpha particles, and singly charge helium ions. The low Mach number of the bow shock enabled the ions to be distinguished upstream and sometimes downstream of the shock. Some of the protons are specularly reflected and produce quasi-periodic fine structures in the velocity distribution functions downstream of the shock. Heavier ions are shown to transit the shock without reflection. However, the gyromotion of the heavier ions partially obscures the fine structure of proton distributions. Additionally, the calculated proton moments are unreliable when the different ion species are not distinguished by the particle detector. The need to high time-resolution mass-resolving ion detectors when investigating collisionless shocks is discussed.