| DOI: | 10.1002/2014GL060628
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| 论文题名: | Generation of unusually low frequency plasmaspheric hiss |
| 作者: | Chen L.; Thorne R.M.; Bortnik J.; Li W.; Horne R.B.; Reeves G.D.; Kletzing C.A.; Kurth W.S.; Hospodarsky G.B.; Spence H.E.; Blake J.B.; Fennell J.F.
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| 刊名: | Geophysical Research Letters
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| ISSN: | 0094-9848
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| EISSN: | 1944-9579
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| 出版年: | 2014
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| 卷: | 41, 期:16 | | 起始页码: | 5702
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| 结束页码: | 5709
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| 语种: | 英语
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| Scopus关键词: | Magnetosphere
; Plasma density
; Density gradients
; Energetic electron
; Generation mechanism
; Injected electrons
; Low-frequency waves
; Propagation characteristics
; Ray-tracing codes
; Substorm injections
; Ray tracing
; frequency analysis
; plasma
; quantitative analysis
; simulation
; wave propagation
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| 英文摘要: | It has been reported from Van Allen Probe observations that plasmaspheric hiss intensification in the outer plasmasphere, associated with a substorm injection on 30 September 2012, occurred with a peak frequency near 100 Hz, well below the typical plasmaspheric hiss frequency range, extending down to ~20 Hz. We examine this event of unusually low frequency plasmaspheric hiss to understand its generation mechanism. Quantitative analysis is performed by simulating wave raypaths via the HOTRAY ray tracing code with measured plasma density and calculating raypath-integrated wave gain evaluated using the measured energetic electron distribution. We demonstrate that the growth rate due to substorm-injected electrons is positive but rather weak, leading to small wave gain (~10 dB) during a single equatorial crossing. Propagation characteristics aided by the sharp density gradient associated with the plasmapause, however, can enable these low-frequency waves to undergo cyclic raypaths, which return to the unstable region leading to repeated amplification to yield sufficient net wave gain (>40 dB) to allow waves to grow from the thermal noise. © 2014. American Geophysical Union. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84906034203&doi=10.1002%2f2014GL060628&partnerID=40&md5=5e59bafa8e136231b6c2b427a4da6e96
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| Citation statistics: |
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| 资源类型: | 期刊论文
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/7112
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| Appears in Collections: | 气候减缓与适应
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作者单位: | Department of Physics, University of Texas at Dallas, Richardson, TX, United States
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| Recommended Citation: | |
Chen L.,Thorne R.M.,Bortnik J.,et al. Generation of unusually low frequency plasmaspheric hiss[J]. Geophysical Research Letters,2014-01-01,41(16).
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