HR: 13:40h
AN: SM43D-01 INVITED     [Abstracts]
TI: Kinetic Aspects of Dispersive Scale Alfvén Waves
AU: * Rankin, R
EM: rankin@phys.ualberta.ca
AF: University of Alberta, Department of Physics, University of Alberta, Edmonton, AB T6G 2J1 Canada
AU: Watt, C
EM: cwatt@space.ualberta.ca
AF: University of Alberta, Department of Physics, University of Alberta, Edmonton, AB T6G 2J1 Canada
AU: Lu, J
EM: jlu@space.ualberta.ca
AF: University of Alberta, Department of Physics, University of Alberta, Edmonton, AB T6G 2J1 Canada
AU: Marchand, R
SM43D-01 AF: University of Alberta, Department of Physics, University of Alberta, Edmonton, AB T6G 2J1 Canada
AB: Ground-based observations and in-situ satellite measurements have firmly established that dispersive scale shear Alfvén waves (SAWs) are associated with electron acceleration on field lines threading the auroral oval. Electron acceleration is attributed to wave-particle interactions involving parallel electric fields in SAWs. In spite of this basic fact, there remains the significant problem of constructing appropriate theory that would explain how parallel electric fields are formed in SAWs across the full range of observed length and timescales. Two-fluid reduced MHD theory provides a conventional approach that is often used. However, it can be shown that at low wave frequencies, the predicted electric field strengths are insufficient to explain precipitation energies of electrons that vary from 100's of eV to several keV. In this paper, we identify the conditions under which two-fluid theory breaks down, and present results of kinetic wave modeling of standing SAWs and propagating SAW pulses. We quantify the conditions under which kinetic theory must be used, and discuss the essential ingredients which are necessary to explain the observed range of electron precipitation energies. Our results are compared with NASA FAST satellite data and data from the Canadian Space Agency rocket experiment GEODESIC
DE: 2704 Auroral phenomena (2407)
DE: 2716 Energetic particles: precipitating
DE: 2721 Field-aligned currents and current systems (2409)
DE: 2752 MHD waves and instabilities (2149, 6050, 7836)
DE: 2753 Numerical modeling
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005