ELF/VLF wave generation using simultaneous CW and modulated HF heating of the ionosphere

摘要: [1] Experimental observations of ELF/VLF waves generated using the dual-beam heating capability High frequency Active Auroral Research Program (HAARP) HF transmitter in Gakona, Alaska, are compared with predictions an ionospheric model that accounts for simultaneous propagation and absorption multiple beams. The output is used to assess three properties observed on ground: signal magnitude, harmonic ratio, power law exponent. Ground-based experimental indicate ionosphere by a CW wave modulated generates significantly lower magnitudes than during periods without heating, consistent predictions. Further modeling demonstrate sensitive dependence magnitude signal. ratio also shown be indicator modification, although it somewhat less magnitude. Last, peak level beam was varied order generation under both single- conditions. Experimental theoretical results accurate evaluation index requires high signal-to-noise ratio; thus modification either or ratio.