HR: 0800h
AN: SM41A-1112    [Abstracts]
TI: Remote Sensing of Relativistic Electron Precipitation Using a VLF Beacon Transmitter at South Pole
AU: * Chevalier, M W
EM: chamonix@stanford.edu
AF: Stanford University, 351 Packard EE Building, Stanford, CA 94305 United States
AU: Inan, U S
EM: inan@nova.stanford.edu
AF: Stanford University, 351 Packard EE Building, Stanford, CA 94305 United States
AB: The Stanford University VLF beacon transmitter located at South Pole has been operating at 19.4 kHz continuously since November 2003. The main utility of the beacon is to serve as a tool for continuously monitoring the effects of relativistic particle precipitation on the D-region of the ionosphere in the auroral regions of the Southern Hemisphere/Antarctica. We present data from the first year of operation, showing VLF beacon signal amplitude and phase as received at Palmer and discuss its characteristics and variations due to diurnal and seasonal effects. The months from April to August are ideal for the beacon observations due to the fact that the VLF great circle path from South Pole to Palmer experiences extended periods of darkness and is thus sensitively disposed to the ionospheric effects of relativistic electron precipitation. We focus our discussion of the VLF data to two periods of high geomagnetic activity, one in April and one in July of 2004. The VLF beacon data are compared directly with energetic particle fluxes measured with the PET-ELo instrument on the SAMPEX sattelite during these same periods. The fluxes observed on SAMPEX are used to generate profiles of ionospheric density in regions along the great circle paths from South Pole to Palmer and a quantitative model of Earth-ionosphere waveguide propagation is used to interpret the observed VLF amplitude and phase changes in terms of relativistic electron flux enhancements.
DE: 2716 Energetic particles, precipitating
DE: 2736 Magnetosphere/ionosphere interactions
DE: 2788 Storms and substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting