An event on simultaneous amplification of exohiss and chorus waves associated with electron density enhancements

TitleAn event on simultaneous amplification of exohiss and chorus waves associated with electron density enhancements
Publication TypeJournal Article
Year of Publication2018
AuthorsZhu, H, Shprits, YY, Chen, L, Liu, X, Kellerman, AC
JournalJournal of Geophysical Research: Space Physics
Date Published10/2018
Keywordselectromagnetic waves; Exohiss; linear theory; Radiation belts; Van Allen Probes
AbstractWhistler mode exohiss are the structureless hiss waves observed outside the plasmapause with featured equatorward Poynting flux. An event of the amplification of exohiss as well as chorus waves was recorded by Van Allen Probes during the recovery phase of a weak geomagnetic storm. Amplitudes of both types of the waves showed a significant increase at the regions of electron density enhancements. It is found that the electrons resonant with exohiss and chorus showed moderate pitch‐angle anisotropies. The ratio of the number of electrons resonating with exohiss to total electron number presented in‐phase correlation with density variations, which suggests that exohiss can be amplified due to electron density enhancement in terms of cyclotron instability. The calculation of linear growth rates further supports above conclusion. We suggest that exohiss waves have potential to become more significant due to the background plasma fluctuation.
URLhttps://agupubs.onlinelibrary.wiley.com/doi/10.1029/2017JA025023
DOI10.1029/2017JA025023
Short TitleJ. Geophys. Res. Space Physics


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