HR: 15:30h
AN: SM53D-08    [Abstracts]
TI: Self-Consistent Kinetic Modeling of Field Line Resonances
AU: * Rankin, R
EM: rankin@phys.ualberta.ca
AF: University of Alberta, Department of Physics, University of Alberta, Edmonton, AB T6G2G7, Canada
AU: Watt, C
EM: cwatt@phys.ualberta.ca
AF: University of Alberta, Department of Physics, University of Alberta, Edmonton, AB T6G2G7, Canada
AB: Field line resonances (FLRs) represent a class of low frequency ULF pulsations in the Pc5 range. At auroral latitudes, on field lines threading the nightside plasma sheet, FLRs can be observed using ground-based magnetometers, where they typically appear with wave frequencies in the range of a few mHz. It is now established that FLRs appear in coincidence with modulations of the optical aurora, as observed using all-sky camera and meridian scanning photometer data from the CANOPUS array in Northern Canada. Optical signatures of FLRs may be due to direct particle energization by FLR wave fields. This, however, remains to be established. In this paper, we present results based on a vlasov-kinetic model of FLRs. The model is 1D in configuration space, but accommodates geomagnetic field line convergence by allowing the perpendicular wavenumber to vary along the field line. We consider the effect of the mirror force and variations in the ambient density and temperature on the evolution of FLRs. We discuss the conditions under which parallel electric fields are generated, and discuss how electrons trapped by the wave fields are able to damp FLRs. We also assess the importance of parallel electric fields in energizing auroral electrons and discuss whether observed FLRs can explain the optical signatures of FLRs.
DE: 2407 Auroral ionosphere (2704)
DE: 2716 Energetic particles: precipitating
DE: 2721 Field-aligned currents and current systems (2409)
DE: 2753 Numerical modeling
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting