| DOI: | 10.1002/2015GL066978
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| 论文题名: | Full-wave modeling of EMIC waves near the He+ gyrofrequency |
| 作者: | Kim E.-H.; Johnson J.R.
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| 刊名: | Geophysical Research Letters
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| ISSN: | 0094-9493
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| EISSN: | 1944-9224
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| 出版年: | 2016
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| 卷: | 43, 期:1 | | 起始页码: | 13
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| 结束页码: | 21
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| 语种: | 英语
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| 英文关键词: | EMIC waves
; mode conversion
; numerical simulation
; polarization reversal
; wave modeling
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| Scopus关键词: | Computer simulation
; Cyclotrons
; Electromagnetic wave propagation in plasma
; Ions
; Magnetoplasma
; Magnetosphere
; Polarization
; Radiation belts
; Ray tracing
; Resonance
; Wave propagation
; Cross-over frequencies
; Cyclotron instability
; Dipolar magnetic fields
; Mode conversions
; Polarization reversals
; Propagation characteristics
; Resonance frequencies
; Wave modeling
; Wave equations
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| 英文摘要: | Electromagnetic ion cyclotron (EMIC) waves are known to be excited by the cyclotron instability associated with hot and anisotropic ion distributions in the equatorial region of the magnetosphere and are thought to play a key role in radiation belt losses. Although detection of these waves at the ground can provide a global view of the EMIC wave environment, it is not clear what signatures, if any, would be expected. One of the significant scientific issues concerning EMIC waves is to understand how these waves are detected at the ground. In order to solve this puzzle, it is necessary to understand the propagation characteristics of the field-aligned EMIC waves, which include polarization reversal, cutoff, resonance, and mode coupling between different wave modes, in a dipolar magnetic field. However, the inability of ray tracing to adequately describe wave propagation near the crossover cutoff-resonance frequencies in multi-ion plasmas is one of reasons why these scientific questions remain unsolved. Using a recently developed 2-D full-wave code that solves the full-wave equations in global magnetospheric geometry, we demonstrate how EMIC waves propagate from the equatorial region to higher magnetic latitude in an electron-proton-He+ plasma. We find that polarization reversal occurs at the crossover frequency from left-hand polarization (LHP) to right-hand (RHP) polarization and such RHP EMIC waves can either propagate to the inner magnetosphere or reflect to the outer magnetosphere at the Buchsbaum resonance location. We also find that mode coupling from guided LHP EMIC waves to unguided RHP or LHP waves (i.e., fast mode) occurs. © 2015. American Geophysical Union. All Rights Reserved. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84956595542&doi=10.1002%2f2015GL066978&partnerID=40&md5=40aae39edd8bbf2e8e7e578c37c8d0ae
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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/10456
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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: | Princeton Center for Heliophysics, Princeton Plasma Physics Laboratory, Princeton University, Princeton, NJ, United States
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| Recommended Citation: | |
Kim E.-H.,Johnson J.R.. Full-wave modeling of EMIC waves near the He+ gyrofrequency[J]. Geophysical Research Letters,2016-01-01,43(1).
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