ELF radiation from the New Zealand power system

Barr, R.

doi:10.1016/0032-0633(79)90130-2

Cited by 6 publications

(3 citation statements)

References 7 publications

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“…Although our calculations are based on the winter midnight ionosphere, there is little difference in electron density between midnight and at 2000 LT (see Bilitza, 2001). These noise values agree with measurements made by Barr (1979) at midday near the end of summer in areas close to Dunedin. Any measurements of the Dunedin ripple control radiation will need to be taken sufficiently far away from all power lines such that local power line harmonic interference and other human made noises do not dominate.…”

Section: Calculated Fields Below the Ionospheresupporting

confidence: 88%

“…We have already mentioned the experimental campaign undertaken in Newfoundland (Yearby et al, 1983). Radiated fields were also measured from a 600 km High Voltage DC (HVDC) link operating between the South and North Islands of New Zealand (Barr, 1979). Observations of the HVDC signal were undertaken from three locations at distances from the base of the DC line of ∼70, 110, and 300 km, respectively.…”

Section: Discussionmentioning

confidence: 99%

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Identifying power line harmonic radiation from an electrical network

2005

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Abstract. It has been suggested that the space environment is being polluted by power line harmonic radiation (PLHR), generated from harmonics of the electrical power transmission frequency (50 or 60 Hz) and radiated into the ionosphere and magnetosphere by long power lines. While some insitu satellite measurements of PLHR have been reported, it has proved difficult to confirm the source and overall significance. The electricity network of the city of Dunedin, New Zealand, is tiny compared to the many large industrial zones found outside New Zealand. However, the 1050 Hz ripple control signal injected into the local electrical grid at regular intervals as a load-control mechanism provides an opportunity for identifying PLHR strengths radiated from a spatially well defined electrical network. In-situ observations by satellites should allow a greater understanding of PLHR and its significance as man-made pollution to nearEarth space. Calculations have been undertaken to estimate the strength of the radiation fields expected from the ripple control signal which is injected into the Dunedin city electrical network. We find that ground-based measurements will not be sensitive enough for detection of the ripple control radiation fields, even during the quietest winter night. While significant power penetrates the lower ionosphere, this is well below the reported threshold required for nonlinear triggering in the Van Allen radiation belts. Some radiated fields at satellite altitudes should be detectable, allowing insitu measurements. At the altitude of the DEMETER mission, the radiated electric fields will not be detectable under any ionospheric conditions. However, we find that the radiated magnetic fields may be detectable by the DEMETER satellite at certain times, although this will be very difficult. Nonetheless, there is the possibility for future experimental campaigns.

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Section: Calculated Fields Below the Ionospheresupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Identifying power line harmonic radiation from an electrical network

2005

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“…Therefore, the propagation process of the ELF wave in the atmosphere and ionosphere can be simulated by utilizing analytical methods. The space between the Earth's surface and the ionosphere is conceptualized and defined as a waveguide, which is called the Earth-ionosphere waveguide system [32][33][34]. We adopted the finite difference time domain method to set up the difference scheme of Maxwell equations and established the propagation mechanism of EM waves in threedimensional spherical coordinates.…”

Section: Earth-ionosphere Waveguidementioning

confidence: 99%

Numerical Study of Global ELF Electromagnetic Wave Propagation with Respect to Lithosphere–Atmosphere–Ionosphere Coupling

et al. 2021

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Before and after earthquakes, abnormal physical and chemical phenomena can be observed by gathering ground-based and satellite data and interpreted by the lithosphere–atmosphere–ionosphere coupling (LAIC) mechanism. In this study, we focused on the mechanism of LAIC electromagnetic radiation and investigated the seismic electromagnetic (EM) wave generated in the lithosphere by earthquakes and its global propagation process from the lithosphere through the atmosphere and into the bottom of ionosphere, in order to analyze the abnormal disturbance of ground-based and space-based observation results. First, analytic formulas of the electrokinetic effect were used to simulate the generation and propagation process of the seismic EM wave in the lithosphere, interpreted as the conversion process of the seismic wave and EM wave in porous media. Second, we constructed a three-dimensional Earth–ionosphere waveguide by applying the finite-difference time-domain (FDTD) algorithm to model the global propagation process of the seismic EM wave into the atmosphere and cavity between the bottom of the ionosphere and the surface of the Earth. By combining the model of the electrokinetic effect in the lithosphere with the numerical model of the Earth–ionosphere waveguide in the atmosphere and ionosphere, we numerically simulated the global transmission process of extremely low-frequency (ELF: 3 Hz–3000 Hz) EM waves which are related to earthquakes. The propagation parameters of coseismic ELF EM waves with different duration times and center frequencies were analyzed and summarized. The simulation results demonstrate that the distribution characteristics of an electric field along longitude, latitude and altitude with time are periodic and the time interval during which an EM wave travels around the whole Earth is approximately 0.155 s when adopting the conductivity of the knee profile. We also compared the observation data with the simulation results and found that the attenuating trends of the ELF electric field are consistent. This proposed ELF EM wave propagation model of lithosphere–atmosphere–ionosphere coupling is very promising for the explanation of abnormal disturbances of ground-based and space-based observation results of ELF EM fields which are associated with earthquakes.

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PLHR emissions observed on satellites

Molchanov¹,

Parrot²

1995

Journal of Atmospheric and Terrestrial Physics

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ELF radiation from the New Zealand power system

Cited by 6 publications

References 7 publications

Identifying power line harmonic radiation from an electrical network

Identifying power line harmonic radiation from an electrical network

Numerical Study of Global ELF Electromagnetic Wave Propagation with Respect to Lithosphere–Atmosphere–Ionosphere Coupling

PLHR emissions observed on satellites

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