Effect of the total solar eclipse of 20 March 2015 on the ELF propagation over high-latitude paths

Propagation of the artificial electromagnetic waves with frequency of 82 Hz in the Earth‐ionosphere waveguide was observed during the solar eclipse on both partially and totally obscured high‐latitude paths with a length of 450–1200 km. Field excitation was monitored by the reference measurements in the near zone of the transmitter, which are free of the ionospheric influence. It is found that the amplitude of the field at the remote points varied depending on the solar illumination and solar elevation angle. We suppose that this effect was probably caused by the increase in the effective height of the ionospheric D layer, just as it was previously observed in VLF. The obtained results demonstrate the response of the propagating extremely low frequency (ELF, 3–300 Hz) wave to the change in the ionospheric boundary. This effect has been for the first time observed in this frequency range during a total solar eclipse. Key Points Artificial ELF electromagnetic waves propagation during the solar eclipse was observed Field at the remote points varied depending on the solar illumination and elevation angle Results demonstrate the response of the ELF waves to the change in the ionospheric boundary