Detection of local and long‐path VLF/ELF radiation from modulated ionospheric current systems

This paper describes the local and long‐path very low frequency/extremely low frequency (VLF/ELF) radiation produced by modulation of the ionospheric current systems during high frequency (HF) heating of the ionospheric D region and very high frequency (VHF) heating of the equatorial electrojet. A brief description of the theory and the geometry of the heating experiment is followed by a discussion of local VLF/ELF radiation detected near the HF transmitter locations at Arecibo, Puerto Rico, and at the Jicamarca Radar Observatory near Lima, Peru. Long‐path detection of VLF/ELF radiation initially recorded on a path from Tromso, Norway, to the Pennsylvania State University in 1981 is updated with current experimental long‐path results over paths between Jicamarca, Peru, and Salinas, Puerto Rico, as well as Arecibo, Puerto Rico, to the Pennsylvania State University.