HR: 10:50h
AN: SM22A-03    [Abstracts]
TI: ELF/VLF Wave-Injection Experiments and Magnetospheric Probing with the HAARP HF Ionospheric Heater
AU: * Go\l kowski, M
EM: mag41@stanford.edu
AF: Stanford University, 350 Serra Mall Packard Building Rm 351, Stanford, CA 94305 United States
AU: Inan, U S
EM: inan@stanford.edu
AF: Stanford University, 350 Serra Mall Packard Building Rm 351, Stanford, CA 94305 United States
AB: Magnetospheric amplification of ducted ELF/VLF signals has been known and documented for over three decades. Research at Siple Station, Antarctica during the period 1972-89 illustrated many cases of ducting, amplification and emission triggering from waves launched on magnetic field lines and reflected from the ionospheric boundary in the conjugate hemisphere. Once reflected (one-hop) and twice reflected (two-hop) signals were found to occur for approximately 45% of transmissions on field lines ranging from L = 3 to L = 5. ELF/VLF wave generation via HF heating of D-region electrojet currents offers the potential for further controlled wave injection experiments. Signals generated by the High Frequency Active Auroral Research Program (HAARP) facility in Alaska have been observed extensively on the ground and in space. Recent observation of one-hop and two-hop echoes generated by HAARP [Inan et al., 2004] offers the ability to study cyclotron resonance wave amplification and emission triggering mechanisms. We report on the characteristics of the echoes and present a survey of statistical occurence of ducted magnetospherically amplified signals excited by the HAARP HF heater. The survey encompasses both geomagnetic activity and local ionospheric conditions.
DE: 2716 Energetic particles, precipitating
DE: 2720 Energetic particles, trapped
DE: 2730 Magnetosphere--inner
DE: 2736 Magnetosphere/ionosphere interactions
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting