The steady electric discharging currents in a lightning channel cause a series of incoherent impulses in the whole frequency range, the amplitudes of which decreases approximately with the inverse frequency. In the ELF-range, technical noise from 50–60 Hz, natural noise from the magnetosphere, etc.
The steady electric discharges within a lightning channel generate a series of uncorrelated pulses across all frequencies, with decreasing amplitudes as frequency increases. In the ELF-frequency range, there is also technical noise from 50-60 Hz and natural noise from the magnetosphere.