Research of Ionospheric Parameters Variations Caused by Power Line Harmonic Radiation Based on DEMETER Satellite Observed Data

Environmental effects caused by power line harmonic radiation (PLHR) have drawn more attention these years. This paper statistically analyzes the variation of the ionospheric parameters due to PLHR's influence. Based on the PLHR events detected above China by DEMETER satellite, we compared the observation data on the ionospheric parameters in the orbits where PLHR occurred, calling it self-orbits, and their related revisiting orbits before and after PLHR occurred. We found that, only a few events show energetic electron pitch angle variation, and the decrease is dominant; the low-energy band electron flux tends to decrease before PLHR occurs. The low-latitude events cause a small variation of flux, while the high-latitude events on the contrary. Comparing satellite observed data and International Reference Ionosphere model data, the variation of electron density and electron temperature show trough and crest tendency respectively, and H+ density and O+ density show crest and trough tendency respectively. These variations of ionospheric parameters may be caused by PLHR, or possibly give rise to the formation and propagation of PLHR in the ionosphere. In all, there is no dominant variation tendency. The influence caused by PLHR on the ionospheric parameters is not obvious.