TY  - JOUR
A1  - Zhu, Hui
A1  - Shprits, Yuri Y.
A1  - Chen, Lunjin
A1  - Liu, Xu
A1  - Kellerman, Adam C.
T1  - An event on simultaneous amplification of exohiss and chorus waves associated with electron density enhancements
JF  - Journal of geophysical research : Space physics
N2  - Whistler mode exohiss are the structureless hiss waves observed outside the plasma pause 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.
Y1  - 2018
U6  - https://doi.org/10.1029/2017JA025023
SN  - 2169-9380
SN  - 2169-9402
VL  - 123
IS  - 11
SP  - 8958
EP  - 8968
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Zhu, Hui
A1  - Chen, Lunjin
A1  - Liu, Xu
A1  - Shprits, Yuri Y.
T1  - Modulation of locally generated equatorial noise by ULF wave
JF  - Journal of geophysical research : Space physics
N2  - In this paper we report a rare and fortunate event of fast magnetosonic (MS, also called equatorial noise) waves modulated by compressional ultralow frequency (ULF) waves measured by Van Allen Probes. The characteristics of MS waves, ULF waves, proton distribution, and their potential correlations are analyzed. The results show that ULF waves can modulate the energetic ring proton distribution and in turn modulate the MS generation. Furthermore, the variation of MS intensities is attributed to not only ULF wave activities but also the variation of background parameters, for example, number density. The results confirm the opinion that MS waves are generated by proton ring distribution and propose a new modulation phenomenon.
Y1  - 2019
U6  - https://doi.org/10.1029/2018JA026199
SN  - 2169-9380
SN  - 2169-9402
VL  - 124
IS  - 4
SP  - 2779
EP  - 2787
PB  - American Geophysical Union
CY  - Washington
ER  -