HR: 08:20h
AN: SM21A-02    [PDF]
TI: Oblique Alfven Waves as a Source for Stable Auroral Arcs
AU: * Rothwell, P L
EM: Paul.Rothwell@hanscom.af.mil
AF: Air Force Research Laboratory/Space Vehicles Directorate, 29 Randolph Rd., Hanscom AFB, MA 01731 United States
AU: Silevitch, M B
EM: msilevit@ECE.NEU.EDU
AF: Center for Electromagnetics Research, Northeastern University, Boston, MA 02115 United States
AU: Falthammar, C
EM: falthammar@plasma.kth.se
AF: Division of Plasma Physics, Alfven Laboratory, Royal Institute of Technology, Stockholm, 70 Sweden
AB: We have recently developed [Silevitch et al., Rothwell et al., 2000 ] a model for the generation of oblique Alfven waves and their role in creating stable auroral arcs. The magnetospheric wave generator, in this approach, arises from the non-adiabatic motion of the O+ ions that, under certain conditions, can form stationary density striations as they drift Earthward from the magnetotail. Associated with these density striations is a periodic static spatial variation of the Earthward current density, which when viewed in the drift frame of the adiabatic hydrogen ions and electrons is seen as a tailward moving current wave. The resulting oblique Alfven wave forms a static wave pattern. As the magnetic-field aligned currents associated with these waves close in the ionosphere, the equatorial plasma constitutes a generator from which spatially alternating magnetic field-aligned currents carry energy to the ionospheric load and form stable auroral arcs. The coupling of the magnetospheric generator to the solar wind will be discussed as well as the implication of more recent results on this work. M. Silevitch, P. Rothwell,L. Block and C.-G. Falthammar, J.Geophys. Res., 105, 10,739-10,749, 2000. P. Rothwell, M. Silevitch, L. Block and C.-G. Falthammar, IEEE Transactions on Plasma Science,28, 2000.
DE: 2407 Auroral ionosphere (2704)
DE: 2411 Electric fields (2712)
DE: 2431 Ionosphere/magnetosphere interactions (2736)
DE: 2704 Auroral phenomena (2407)
DE: 2736 Magnetosphere/ionosphere interactions
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting