DOI: 10.1002/grl.50800
论文题名: Excitation of poloidal standing Alfvén waves through drift resonance wave-particle interaction
作者: Dai L. ; Takahashi K. ; Wygant J.R. ; Chen L. ; Bonnell J. ; Cattell C.A. ; Thaller S. ; Kletzing C. ; Smith C.W. ; Macdowall R.J. ; Baker D.N. ; Blake J.B. ; Fennell J. ; Claudepierre S. ; Funsten H.O. ; Reeves G.D. ; Spence H.E.
刊名: Geophysical Research Letters
ISSN: 0094-8660
EISSN: 1944-8391
出版年: 2013
卷: 40, 期: 16 起始页码: 4127
结束页码: 4132
语种: 英语
英文关键词: drift resonance
; poloidal standing wave
; ring current
Scopus关键词: Azimuthal electric fields
; Cross-spectral analysis
; Fusion plasma devices
; Phase space densities
; Radial magnetic field
; Ring currents
; Standing wave
; Wave-particle interactions
; Collisionless plasmas
; Electric fields
; Electron cyclotron resonance
; Ions
; Phase space methods
; Plasma devices
; Probes
; Radiation belts
; Spectrum analysis
; Wave plasma interactions
; Resonance
; azimuth
; collision
; electric field
; flux measurement
; identification method
; instability
; magnetic field
; magnetosphere
; oscillation
; particulate matter
; resonance
; standing wave
; wave generation
英文摘要: Drift-resonance wave-particle interaction is a fundamental collisionless plasma process studied extensively in theory. Using cross-spectral analysis of electric field, magnetic field, and ion flux data from the Van Allen Probe (Radiation Belt Storm Probes) spacecraft, we present direct evidence identifying the generation of a fundamental mode standing poloidal wave through drift-resonance interactions in the inner magnetosphere. Intense azimuthal electric field (Eφ) oscillations as large as 10mV/m are observed, associated with radial magnetic field (Br) oscillations in the dawn-noon sector near but south of the magnetic equator at L∼5. The observed wave period, Eφ/Br ratio and the 90° phase lag between Br and Eφ are all consistent with fundamental mode standing Poloidal waves. Phase shifts between particle fluxes and wave electric fields clearly demonstrate a drift resonance with ∼90 keV ring current ions. The estimated earthward gradient of ion phase space density provides a free energy source for wave generation through the drift-resonance instability. A similar drift-resonance process should occur ubiquitously in collisionless plasma systems. One specific example is the "fishbone" instability in fusion plasma devices. In addition, our observations have important implications for the long-standing mysterious origin of Giant Pulsations. Key Points Unambiguous identification of drift-resonance in magnetosphere Broad implications for ring current and ground observations Drift-resonance similar to fishbone instability in Tokamak. © 2013. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84882736611&doi=10.1002%2fgrl.50800&partnerID=40&md5=9bdcda3726d766a9f1ef03762c673c10
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/5924
Appears in Collections: 气候减缓与适应
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作者单位: School of Physics and Astronomy, University of Minnesota, Twin Cites, Minneapolis MN 55414, United States
Recommended Citation:
Dai L.,Takahashi K.,Wygant J.R.,et al. Excitation of poloidal standing Alfvén waves through drift resonance wave-particle interaction[J]. Geophysical Research Letters,2013-01-01,40(16).