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Title: Observational Evidence of the Excitation of Magnetosonic Waves by an He ++ Ion Ring Distribution
Abstract

We report plasma wave observations of equatorial magnetosonic waves at integer harmonics of the local gyrofrequency of doubly ionized helium (). The waves were observed by Van Allen Probe A on 08 Feb 2014 when the spacecraft was in the afternoon magnetic local time sector nearinside 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 energeticions in the near‐Earth space plasma environment.

 
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Award ID(s):
1854440
NSF-PAR ID:
10375328
Author(s) / Creator(s):
 ;  ;  ;  
Publisher / Repository:
DOI PREFIX: 10.1029
Date Published:
Journal Name:
Journal of Geophysical Research: Space Physics
Volume:
126
Issue:
8
ISSN:
2169-9380
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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