HF modulated ionospheric currents

The HAARP HF facility is used to modulate the components of the auroral electrojet that flow in the D‐region of the ionosphere, creating ELF/VLF radiation which is then measured at a receiver co‐located with the HAARP HF antenna. An HF heating model is coupled to a full wave plasma interaction FDTD code to determine the ELF/VLF response of the ionospheric plasma to the modulated HF stimulation. The predicted FDTD fields on the ground are found to be in remarkable agreement with those measured at a receiver co‐located with HAARP. The FDTD code also predicts an upwardly propagating whistler mode that is tightly bound to the magnetic field lines.