DOI: 10.1002/grl.50307
论文题名: Alfvén Mach number and IMF clock angle dependencies of sunward flow channels in the magnetosphere
作者: Eriksson S. ; Rastätter L.
刊名: Geophysical Research Letters
ISSN: 0094-9168
EISSN: 1944-8899
出版年: 2013
卷: 40, 期: 7 起始页码: 1257
结束页码: 1262
语种: 英语
英文关键词: magnetosphere-ionosphere-thermosphere coupling
; reconnection flows
Scopus关键词: Alfven Mach number
; Defense Meteorological Satellite Programs
; Interplanetary coronal mass ejections
; Interplanetary magnetic fields
; Ionospheric channels
; Magnetic null points
; Neutral densities
; reconnection flows
; Aerodynamics
; Channel flow
; Clocks
; Ionosphere
; Mach number
; Magnetosphere
; Solar wind
; Magnetohydrodynamics
; ionosphere
; magnetic field
; magnetosphere
; solar wind
; thermosphere
英文摘要: Interplanetary coronal mass ejections associated with strong interplanetary magnetic field (IMF) By have been shown to enhance the neutral density in low Earth orbit. The enhancement has been linked to strong downward Poynting fluxes embedded within ionospheric channels of significant sunward ExB drift (2000-3000 m/s). Here we present MHD results describing the magnetospheric counterpart of the ionospheric flow channel that Defense Meteorological Satellite Program (DMSP) encountered on 15 May 2005. It is shown that the clock angle of maximum sunward flow (θFC) depends on the IMF clock angle θFC = α * θIMF - 1.3° with α = (0.30, 0.38, 0.43, 0.45) at X = (4, 2, 0, -2) RE. This is poleward of the magnetic null point region. The flow also depends on the solar wind Alfvén Mach number Vx = Vx0 - δv * MA. The critical MA = Vx0 / δV for Vx = 0 decreases from MA = 3.42 (X = 4 RE) to MA = 2.40 (X = -2 RE). The low MA and θIMF conditions that characterized the X = 2 RE flow and resulted in strong Poynting flux occurred for 16% of all 167 h in 1998-2008 with Dst < -180 nT. Key Points The sunward flow location (AFC) depends on the IMF clock angle as AFC=c*ICL The flow channel is found systematically poleward of the X=0 null point region The maximum sunward flow depends on the Alfven Mach number as Vx=Vx0-dV*MA ©2013. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876902590&doi=10.1002%2fgrl.50307&partnerID=40&md5=d8c31cb677d8a30142922c5411a1a39b
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/6432
Appears in Collections: 气候减缓与适应
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作者单位: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO, United States
Recommended Citation:
Eriksson S.,Rastätter L.. Alfvén Mach number and IMF clock angle dependencies of sunward flow channels in the magnetosphere[J]. Geophysical Research Letters,2013-01-01,40(7).