Overview of power-line radiation and its coupling to the ionosphere and magnetosphere

Abstract

Forward. The subject of 'Power-Line Radiation and its Coupling to the Ionosphere and Magnetosphere' is one of the topics of growing interest as an interdisciplinary problem on the impact of man-made or power-line systems on natural radio noise in our environment. Obviously we have two situations in terms of locations of the primary source origin or transmitting and receiving sites. One is the case when a man-made or power-line system is active as a transmitting antenna or radiator and radiates electromagnetic waves that tend to couple to the ionosphere and magnetosphere. The other is the opposite case where a man-made or power-line system is passive as a receiving antenna and the primary source origin is located in the ionosphere or magnetosphere. Then, potential differences of finite conductivity induced within the Earth produce a large quasi-de current in a power-line system through its neutral grounded points.While both these cases are currently receiving considerable attention over a wide range of interdisciplinary and multidisciplinary communities among man-made and natural radio noise workers, the study of powerline characteristics as a transmitting or receiving system or antenna is not new, going back as early as to the 1920s (Beverage et al., 1923), but has been a long-standing problem over several decades. This forms the groundwork for resolving environmental problems of the interference due to electromagnetic induction and radiation from man-made or power-line systems. In spite of a large number of investigations on wave propagation along and radiation from a wire above the ground (Sunde, 1968), to which all the problems are basically reduced, its physical mechanism of radiation is surprisingly still not well understood (Jenssen, 1949). We therefore begin with a brief survey of this problem, as details are discussed in a separate article in this issue.

Power line harmonic radiation observed by the DEMETER spacecraft at 50/60 Hz and low harmonics

“…A likely explanation for this discrepancy is the limited time resolution of the magnetometer data that we used for the calculation of GIC proxies (1 min), which is not able to capture all the short‐term variability analyzed by Viljanen et al [] and Viljanen et al [], who used the data with time resolution of 1 s. Enhanced PLHR intensities at the times of large GICs are consistent with the case‐study results reported by Hayashi et al []. A likely interpretation is that the quasi‐DC current induced in a power line system distorts the power line current waveforms due to a transformer‐core saturation, resulting thus in a more intense radiation [ Hayashi et al , ; Kikuchi , ].…”

“…Although the intensity of the PLHR events is generally rather low, they may trigger new electromagnetic emissions [Park and Helliwell, 1983;Nunn et al, 1999;Parrot and Němec, 2009;Parrot et al, 2014] and possibly contribute to electron precipitation [Tatnall et al, 1983;Bullough, 1995;Prakash et al, 2009]. Propagation of PLHR events from their source power line up to the satellite altitudes was considered by Kikuchi [1983], Ando et al [2002], Němec et al [2008], and Jing et al [2014]. Numerical results obtained by Ando et al [2002] and Jing et al [2014] show that while the effect of the radiation from a power line is limited to a relatively small geographical region at frequencies below the Earth-ionosphere waveguide cutoff frequency, the affected region becomes much larger if guided modes exist.…”

Theoretical analysis on the penetration of power line harmonic radiation into the ionosphere

“…This PLHR is known to be occurring mainly on field lines grounded on major industrial areas in the world. The PLHR penetrates through the lower ionosphere and is guided along a field‐aligned duct to the magnetospheric equatorial region where the wave‐particle interaction takes place, giving rise to wave amplification and stimulation of new emissions [e.g., Bullough , 1983, 1995; Helliwell et al , 1975; Park and Helliwell , 1978; Parrot , 1994; Molchanov et al , 1991; Kikuchi , 1983]. Hence, in order to estimate quantitatively the magnetospheric effect (the wave‐particle interaction), we have to estimate the transmission characteristics of PLHR in the ionosphere.…”