DOI: 10.1002/2014GL059211
论文题名: Coherent structure generated in the boundary layer of a laboratory-created ionospheric depletion
作者: Liu Y. ; Cao J. ; Xu L. ; Zhang X. ; Wang P. ; Wang J. ; Du Y. ; Zheng Z.
刊名: Geophysical Research Letters
ISSN: 0094-10314
EISSN: 1944-10045
出版年: 2014
卷: 41, 期: 5 起始页码: 1413
结束页码: 1419
语种: 英语
英文关键词: coherent structure
; electron density gradient
; electron-ion hybrid instability
; ionospheric depletion
; sheared E×B flow
Scopus关键词: Boundary layers
; Carrier concentration
; Electron density measurement
; Ions
; Plasmas
; Shear flow
; Spectrum analysis
; Coherent structure
; Digital spectral analysis
; Electron ions
; Electron-density gradients
; ionospheric depletion
; Laboratory experiments
; Plasma irregularities
; Steep density gradients
; Electrons
; atmospheric electricity
; boundary layer
; electron density
; ionosphere
; plasma
英文摘要: Laboratory experiments have been conducted to simulate the boundary processes of ionospheric depletion. The ionospheric depletion was modeled through releasing depletion chemical (SF6) into the ambient plasmas. These plasmas were segregated into two regions by a boundary layer of width electric scale length. In the localized boundary layer, the electron density decreased sharply that yielded steep density gradients. Meanwhile, the floating potential increased in the time scales of the lower hybrid (LH) period, which produced strong sheared electron flows. The shear frequency ωs= VE/LE, which characterizes the sheared flow, is much larger than the LH frequency ωLH. A coherent structure was observed when the floating potential fluctuations were analyzed using digital spectral analysis techniques. Comparison with the theory indicated that the structure is driven by the electron-ion hybrid instability which is generated owing to the nonlinear coupling between the electron density gradient and the sheared electron flow. Our results are important to study the early phase nonlinear evolution of the ionospheric depletion, especially in the development of plasma irregularities and turbulence in the boundary layer. Key Points The ionospheric depletion was simulated in a laboratory A vortex-like coherent structure was observed The structure is driven by electron-ion hybrid instability ©2014. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84895913077&doi=10.1002%2f2014GL059211&partnerID=40&md5=86051d002011d66b9441436dba84f628
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/7578
Appears in Collections: 气候减缓与适应
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作者单位: CAS Key Laboratory of Geospace Environment, Modern Physics Department, University of Science and Technology of China, Hefei, China
Recommended Citation:
Liu Y.,Cao J.,Xu L.,et al. Coherent structure generated in the boundary layer of a laboratory-created ionospheric depletion[J]. Geophysical Research Letters,2014-01-01,41(5).