DOI: 10.1029/2018JA025393
Scopus记录号: 2-s2.0-85052157728
论文题名: Statistical Results of Multiband Chorus by Using THEMIS Waveform Data
作者: Gao X. ; Lu Q. ; Wang S.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 7 起始页码: 5506
结束页码: 5515
语种: 英语
英文关键词: lower band cascade
; lower-band chorus
; multiband chorus
; nonlinear process
; upper-band chorus
英文摘要: In this paper, we have studied thousands of multiband chorus events in the Earth's magnetosphere by utilizing seven-year THEMIS waveform data. There are two types of multiband chorus events in the magnetosphere: electromagnetic multiband chorus (EM-MBC) event, where two-band structure is found in both magnetic and electric spectrograms, and quasi-electrostatic multiband chorus (QE-MBC) event, where two-band structure is only detected in the electric spectrogram. EM-MBC events preferentially occur at low L-shells on the nightside but at high L-shells on the dayside. In EM-MBC events, lower-band waves typically have relatively larger magnetic amplitudes (>100 pT) and finite wave normal angles (10°–30°). The magnetic amplitudes of upper-band harmonic waves are found to be typically smaller than 30 pT and peak in the range of <5 pT. QE-MBC events tend to be detected at low L-shells on both dayside and nightside. They distribute mainly at relatively higher magnetic latitudes (6° to 15°) in the dawn sector. Lower-band chorus in QE-MBC events are typically highly oblique with very large wave normal angles (>60°), and their electric amplitudes peak in the range of 5–15 mV/m. For upper-band harmonic waves, their electric amplitudes mainly concentrate in the range of 0.15–0.5 mV/m. MBC events occupy a large population in upper-band chorus observed in the magnetosphere, which even contribute nearly half of upper-band chorus within L < 10RE. Our study not only provides the first statistical results of MBC events but also reveals the significant role of the lower band cascade in generating upper-band chorus waves in the magnetosphere. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/113647
Appears in Collections: 气候减缓与适应
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作者单位: CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Science, University of Science and Technology of China, Hefei, China; Collaborative Innovation Center of Astronautical Science and Technology, Harbin, China
Recommended Citation:
Gao X.,Lu Q.,Wang S.. Statistical Results of Multiband Chorus by Using THEMIS Waveform Data[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(7)