Observational evidence of the excitation of magnetosonic waves by an He ion ring distribution

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Keywords
Abstract
Abstract We report plasma wave observations of equatorial magnetosonic waves at integer harmonics of the local gyrofrequency of doubly-ionized helium (He). The waves were observed by Van Allen Probe A on 08 Feb 2014 when the spacecraft was in the afternoon magnetic local time sector near inside of the plasmasphere. Analysis of the complementary in-situ energetic ion measurements (1-300 keV) reveals the presence of a helium ion ring distribution centered near 30 keV. Theoretical linear growth rate calculations suggest that the local plasma and field conditions can support the excitation of the magnetosonic waves from the unstable ring distribution. This represents the first report of the generation of magnetosonic equatorial noise via a ring distribution in energetic He ions in the near-Earth space plasma environment.
Notes
Year of Publication
2021
Journal
Journal of Geophysical Research: Space Physics
Volume
n/a
Number
Number of Pages
e2021JA029532
Date Published
07/2021
URL
https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2021JA029532
DOI
https://doi.org/10.1029/2021JA029532