HR: 0800h
AN: SM51B-03    [Abstracts]
TI: Stationary Alfven Waves
AU: Finnegan, S M
EM: sfinnega@mix.wvu.edu
AF: West Virginia Univ., Physics Dept., Morgantown, WV 26506-6315, United States
AU: * Knudsen, D J
EM: knudsen@phys.ucalgary.ca
AF: Univ. of Calgary, Dept. of Physics and Astronomy, Calgary, ALB T2N 1N4, Canada
AU: Koepke, M E
EM: mkoepke@wvu.edu
AF: West Virginia Univ., Physics Dept., Morgantown, WV 26506-6315, United States
AB: A nonlinear, quasineutral, collisional, two-fluid model of uniform plasma convection across field-aligned current sheets is developed to describe stationary Alfven (StA) waves. Previously, Knudsen [JGR, 1996] showed that, in the absence of collisions, stationary inertial Alfven (StIA) waves can accelerate electrons parallel to the magnetic field and cause time-independent plasma-density variations having spatial periodicity in the direction of the convective flow over a broad range of spatial scales and energies. StA waves may play a role in auroral arc formation. Here, Knudsen's model has been generalized for warm, collisional plasma. For StIA waves, dissipative effects of ion collisions are shown to alter the perpendicular ac and dc structure of parallel electron drift velocity, and electron collisions are shown to either increase or decrease the field-aligned electron energy, depending on the initial electron drift speed. Non-zero temperatures are shown to affect the perpendicular periodicity of the StIA wave structure and have minimal effect on the wave amplitude. Changes to the perpendicular structure of parallel electron drift velocity are shown to be less sensitive to temperature effects than to collisional effects. Similar to StIA waves, stationary kinetic Alfven (StKA) waves carry a field-aligned component of electric field, which is found to modulate the field-aligned electron velocity, and accelerate electrons to speeds in excess of the local Alfven speed. Unlike StIA waves, StKA waves modulate the direction of field aligned electron flow. Finite electron resistivity supports the StKA wave field and causes the enhancement of field-aligned electron energy. Ion collisions either increase or decrease the field-aligned electron energy, depending on the initial electron drift speed. This research is supported by NSF and NSERC (Canada).
DE: 7829 Kinetic waves and instabilities
DE: 7831 Laboratory studies and experimental techniques
DE: 7846 Plasma energization
DE: 7867 Wave/particle interactions (2483, 6984)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly