ELF-VLF atmospheric waveforms under night-time ionospheric conditions
نویسندگان
چکیده
منابع مشابه
ELF/VLF Wave Radiation Produced by an Equatorial Ionospheric Heater
Intense HF radiation from a ground-based facility heats the D-region of the ionosphere. The heating modifies the electron energy distribution function, which is found by solving the kinetic equation at each spatial location. The solution selfconsistently takes into account attenuation of HF radiation due to modified HF conductivity. A modulation HF radiation at ELF/VLF frequencies creates corre...
متن کاملObservations of ionospheric ELF and VLF wave generation by excitation of the thermal cubic nonlinearity.
Extremely-low-frequency (ELF, 3-3000 Hz) and very-low-frequency (VLF, 3-30 kHz) waves generated by the excitation of the thermal cubic nonlinearity are observed for the first time at the High-Frequency Active Auroral Research Program high-frequency transmitter in Gakona, Alaska. The observed ELF and VLF field amplitudes are the strongest generated by any high frequency (HF, 3-30 MHz) heating fa...
متن کاملEnhanced ionospheric ELF/VLF generation efficiency by multiple timescale modulated heating
[1] It is shown theoretically that for high power HF ionospheric heaters, such as the current HAARP heater, the HF to VLF conversion can increase significantly by using a two-timescale heating. A long heating pulse, tp 1minute, is followed over the same timescale period bymodulation at the desired ELF/VLF frequency. The long pulse reduces the electron-ion recombination coefficient, resulting in...
متن کاملELF/VLF wave generation from the beating of two HF ionospheric heating sources
[1] It is well established that Extremely Low Frequency (ELF, 0.3–3 kHz) and Very Low Frequency (VLF, 3–30 kHz) radio waves can be generated via modulated High Frequency (HF, 3–10 MHz) heating of the lower ionosphere (60–100 km). The ionospheric absorption of HF power modifies the conductivity of the lower ionosphere, which in the presence of natural currents such as the auroral electrojet, cre...
متن کاملModulation of auroral electrojet currents using dual modulated HF beams with ELF phase offset, a potential Dregion ionospheric diagnostic
[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 H...
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ژورنال
عنوان ژورنال: Annales Geophysicae
سال: 1996
ISSN: 1432-0576
DOI: 10.1007/s00585-996-0033-7