| DOI: | 10.1002/2015GL064237
|
| 论文题名: | Wave normal angle and frequency characteristics of magnetosonic wave linear instability |
| 作者: | Chen L.
|
| 刊名: | Geophysical Research Letters
|
| ISSN: | 0094-8676
|
| EISSN: | 1944-8407
|
| 出版年: | 2015
|
| 卷: | 42, 期:12 | | 起始页码: | 4709
|
| 结束页码: | 4715
|
| 语种: | 英语
|
| 英文关键词: | equatorial noise
; instability
; ion Bernstein wave
; magnetosonic wave
; radiation belt
; ring current
|
| Scopus关键词: | Ions
; Plasma stability
; Radiation belts
; Electron acceleration
; Equatorial noise
; Frequency characteristic
; Instability characteristics
; Ion Bernstein wave
; Magnetosonic waves
; Maxwellian distribution
; Ring currents
; Stability
; anisotropy
; electric field
; electromagnetic wave
; frequency analysis
; harmonic analysis
; instability
; linearity
; noise
; plasma
; velocity profile
; wave propagation
|
| 英文摘要: | Magnetosonic waves, also known as equatorial noise emission, can be unstable in the presence of ion ring velocity distribution of ring current population. Earlier studies have demonstrated that such instability can occur near proton harmonic frequencies and near perpendicular propagation with a narrow range of wave normal angle about 90° and that the waves may contribute significantly to electron acceleration in the radiation belt. However, this effect is sensitive to the values of wave normal angles. Instability characteristics in the regime of weak instability, in particular the dependence on the wave frequency and wave normal angle, is investigated for an ion ring distribution modeled by subtraction of two anisotropic Maxwellian distributions. It is found that two types of instabilities, resonant and nonresonant, occur near 90° wave normal angles. Physics of the two instabilities is explained and discussed. The resonant instability, occurring at a finite parallel wave number k∥, is caused by resonant protons near 90° pitch angle, while the nonresonant instability, occurring for a vanishing k∥, is driven by all thermal protons. A formula for the linear nonresonant instability is derived and generalized for an arbitrary ion distribution. © 2015. American Geophysical Union. All Rights Reserved. |
| URL: | https://www.scopus.com/inward/record.uri?eid=2-s2.0-84948711923&doi=10.1002%2f2015GL064237&partnerID=40&md5=69508860887b2c23987c17116579f3f2
|
| Citation statistics: |
|
| 资源类型: | 期刊论文
|
| 标识符: | http://119.78.100.158/handle/2HF3EXSE/8292
|
| Appears in Collections: | 科学计划与规划
气候变化与战略
|
|
There are no files associated with this item.
|
|
作者单位: | Department of Physics, University of Texas at Dallas, Richardson, TX, United States
|
| Recommended Citation: | |
Chen L.. Wave normal angle and frequency characteristics of magnetosonic wave linear instability[J]. Geophysical Research Letters,2015-01-01,42(12).
|
|
|