| DOI: | 10.1002/2014GL062838
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| 论文题名: | Polarization observations of 4fce auroral roar emissions |
| 作者: | Sato Y.; Kadokura A.; Ogawa Y.; Kumamoto A.; Katoh Y.
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| 刊名: | Geophysical Research Letters
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| ISSN: | 0094-9045
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| EISSN: | 1944-8776
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| 出版年: | 2015
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| 卷: | 42, 期:2 | | 起始页码: | 249
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| 结束页码: | 255
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| 语种: | 英语
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| 英文关键词: | auroral roar
; mode conversion
; polarization
; upper hybrid waves
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| Scopus关键词: | Cyclotrons
; Electric excitation
; F region
; Geomagnetism
; Ionosphere
; Loop antennas
; Storms
; Auroral roar
; Auroral roar
; Ionospheric conditions
; Ionospheric conditions
; Ionospheric electron
; Ionospheric electron
; Mode conversions
; Mode conversions
; Polarization measurements
; Polarization measurements
; Polarization observations
; Tongue of ionizations
; Upper-hybrid waves
; Polarization
; atmospheric wave
; aurora
; geomagnetic field
; ionization
; ionosphere
; polarization
; Iceland
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| 英文摘要: | We report on the first polarization measurement of auroral roar emissions near 4 times the ionospheric electron cyclotron frequency (4fce). A ground-based passive receiver that uses orthogonal loop antennas, installed in Iceland, revealed the sense of polarization of 11 events of 4fce roar emissions. In 9 of 11 cases, 4fce roar was left-handed elliptically polarized, namely, O-mode waves. The O-mode 4fce roar was observed under both sunlit and dark ionospheric conditions during geomagnetic storms. For O-mode 4fce roar generation, satisfaction of the matching condition where upper hybrid frequency (fUH) equals 4fce requires a high-density, F region ionosphere, even during darkness, which might be attributed to auroral precipitation or tongue of ionization. In two cases, right-handed elliptically polarized 4fce roar was observed during darkness hours and the main phase of a geomagnetic storm. This polarization indicates that nonlinear coupling of two upper hybrid waves may also work to generate X-mode 4fce roar. © 2015. American Geophysical Union. All Rights Reserved. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84923632177&doi=10.1002%2f2014GL062838&partnerID=40&md5=0a8593e7de928961cbad0d8eacb3325f
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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/8661
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| Appears in Collections: | 科学计划与规划
气候变化与战略
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作者单位: | National Institute of Polar Research, Tokyo, Japan
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| Recommended Citation: | |
Sato Y.,Kadokura A.,Ogawa Y.,et al. Polarization observations of 4fce auroral roar emissions[J]. Geophysical Research Letters,2015-01-01,42(2).
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