Modulation of auroral electrojet currents using dual modulated HF beams with ELF phase offset, a potential D‐region ionospheric diagnostic. Issue 5 (3rd May 2013)

• Record Type: Journal Article
• Authors: Gołkowski, M.; Cohen, M. B.; Moore, R. C.
• Is Part Of: Journal of geophysical research. Volume 118:Issue 5(2013:May)
• Page Start: 2350
• Page End: 2358
• Publication Date: 2013-05-03
• Subjects: HF Heating -- HAARP -- D‐region -- ELF/VLF Generation -- Electrojet -- Diagnostics; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/jgra.50230
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract : [1] Experiments at the ionospheric heating facility of the High Frequency Active Auroral Research Program (HAARP) are performed employing dual HF beams amplitude modulated at ELF/VLF with a phase offset between the two modulation waveforms. The amplitude of the observed ELF/VLF waves is strongly dependent on the imposed ELF/VLF phase offset, the modulation waveform, and the orientation of the HF beams. Data from two ground stations are interpreted using simulations of modulated heating power envelopes as well as a comprehensive model of ionospheric ELF/VLF generation. It is found that two colocated vertical beams HF beams excite a single ionospheric ELF/VLF source, but independent ELF/VLF sources can be induced in the ionospheric region above the heater if the HF beams are offset from zenith to intersect at their 3 dB points. Furthermore, the use of two vertical HF beams with ELF phase offset is found to be a potential diagnostic method for the ionospheric D region. Key Points: It is not feasible to create a vertical ELF phased array Dual beam phasing offers a new way to diagnose D-region in real time. Modulated HF beams separated at 3dB points excite independent ELF sources