Van Allen Probes Bibliography is from August 2012 through September 2021 Notice:
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A Case Study of Transversely Heated Low-Energy Helium Ions by EMIC Waves in the Plasmasphere
Author | Kim, Khan-Hyuk; Kwon, Hyuck-Jin; Lee, Junhyun; Jin, Ho; Seough, Jungjoon; |
Keywords | Van Allen Probes |
Abstract | Abstract The Van Allen Probe A spacecraft observed strong ∼0.5-Hz helium (He+) band and weak ∼0.8-Hz hydrogen (H+) band EMIC waves on April 17, 2018, at L = ∼4.5–5.2, in the dawn sector, near the magnetic equator, and close to the plasmapause. We examined low-energy ion fluxes observed by the Helium Oxygen Proton and Electron (HOPE) instrument onboard Van Allen Probe A during the wave interval and found that low-energy He+ flux (<10 eV) enhancements occur nearly simultaneously with He-band and H-band EMIC wave power enhancements in a direction mostly perpendicular to the background magnetic field without significant low-energy H+ and O+ flux variations. We suggest that cold He+ ions (<1 eV) are preferentially and transversely heated up 10 eV through the interaction with EMIC waves inside the plasmasphere. The low-Earth orbit spacecraft observed localized precipitations of energetic protons in the upper ionosphere at subauroral latitudes near the magnetic field footprint of Van Allen Probe A. Our observations provide a clear evidence that EMIC waves play an important role in the overall dynamics in the inner magnetosphere, contributing to the high-energy particle loss and low-energy particle energization. |
Year of Publication | 2021 |
Journal | Journal of Geophysical Research: Space Physics |
Volume | 126 |
Number of Pages | e2020JA028560 |
Section | |
Date Published | 02/2021 |
ISBN | |
URL | https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020JA028560 |
DOI | https://doi.org/10.1029/2020JA028560 |