HR: 16:15h
AN: SH54A-04    [Abstracts]
TI: Auroral Particle Acceleration by Kinetic Alfvén Waves
AU: * Lysak, R L
EM: bob@aurora.space.umn.edu
AF: University of Minnesota, Tate Laboratory of Physics 116 Church Street SE, Minneapolis, MN 55455 United States
AU: Song, Y
EM: yan@aurora.space.umn.edu
AF: University of Minnesota, Tate Laboratory of Physics 116 Church Street SE, Minneapolis, MN 55455 United States
AB: The auroral acceleration region is perhaps the most accessible and well-studied particle acceleration region in the solar system, and provides an example of particle acceleration in a strongly magnetized plasma that may give insight into other planetary magnetospheres, the solar corona and pulsar magnetospheres. It is now well accepted that in addition to quasi-static acceleration of auroral particles in parallel electric fields, some auroral particle signatures are clearly associated with field-aligned acceleration that can be attributed to kinetic Alfvén waves. Previous work has led to a non-local kinetic theory of Alfvén waves that takes into account the strong gradients in the Alfvén speed above the ionosphere on auroral field lines. However, this work has involved an equilibrium with no static parallel electric field. On the other hand, observations indicate that inverted-V signatures generally associated with static fields and field-aligned acceleration in Alfvén waves coexist on the same field lines. The kinetic theory of Alfvén waves in the auroral zone has been extended to include such static fields, which lead to new particular populations (reflected ionospheric electrons, trapped electrons) not present in the zero-field equilibrium.
DE: 2704 Auroral phenomena (2407)
DE: 2736 Magnetosphere/ionosphere interactions
DE: 2752 MHD waves and instabilities
DE: 7827 Kinetic and MHD theory
DE: 7867 Wave/particle interactions
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly