We present an overview, based on satellite observations at low Earth orbits, on electromagnetic radiation from ground power transmission lines at an industrial frequency 50–60 Hz. Particular attention has been given to Chibis-M and DEMETER satellite observations. The electric 40-cm antenna of the micro-satellite often recorded 50–60 Hz radiation (known as Power Line Emission (PLE)) when it flew over industrialized areas of the planet. The PLE spectral amplitude varied from 1.2 to 18 (μV/m)/Hz0.5, which corresponds to the electric field amplitude E~1 μV/m. We report results of numerical calculations of the electromagnetic response of the atmosphere and ionosphere to a large-scale surface emitter at a frequency of 50 Hz. According to simulation results, PLE with an intensity of ~1 μV/m observed on satellites in the nightside ionosphere at midlatitudes can be excited by an unbalanced current 8–10 A in a power transmission line above the earth's crust with conductivity of 10–3 S/m. At middle and low latitudes with an inclined geomagnetic field, the maximum response in the upper ionosphere to the transmission line radiation should be seen shifted equatorward, although this shift is less than that upon guidance by the geomagnetic field. The maximum amplitude of the electromagnetic response of the ionosphere to the power transmission line emission decreases for an inclined geomagnetic field, but insignificantly. To date, the PLE intensity in near-Earth space has turned out to be higher than the intensity of natural radiation in this range (Schumann resonances and ion whistlers), and continues to grow with the technological development of mankind.
CM6: a comprehensive geomagnetic field model derived from both CHAMP and Swarm satellite observations
