Home » Zhu et al. 2018

An Event on Simultaneous Amplification of Exohiss and Chorus Waves Associated With Electron Density Enhancements

Zhu H., Y. Y. Shprits, L. Chen, X. Liu, A. C. Kellerman, (2018), An Event on Simultaneous Amplification of Exohiss and Chorus Waves Associated With Electron Density Enhancements, J. of Geophys. Res. [Space Physics], 123, 8958-8968, doi:10.1029/2017JA025023

Abstract

Abstract Whistler 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.

Authors (sorted by name)

Chen Kellerman Liu Shprits Zhu

Journal / Conference

Journal Of Geophysical Research (Space Physics)

Grants

637302 AGS‐1203747 AGS‐1405041 NNX10AK99 NNX13AE34G NNX15AF55G

Bibtex

@article{doi:10.1029/2017JA025023,
author = {Zhu, Hui and Shprits, Yuri Y. and Chen, Lunjin and Liu, Xu and Kellerman, Adam C.},
title = {An Event on Simultaneous Amplification of Exohiss and Chorus Waves Associated With Electron Density Enhancements},
journal = {Journal of Geophysical Research: Space Physics},
volume = {123},
number = {11},
pages = {8958-8968},
keywords = {radiation belts, exohiss, linear theory, electromagnetic waves},
doi = {10.1029/2017JA025023},
url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2017JA025023},
eprint = {https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2017JA025023},
abstract = {Abstract Whistler 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.},
year = {2018}
}