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Electric and magnetic fields were measured during the summer of 1998 in south-central Ontario within the business district of 60 communities, ranging in size from 1000 to 2.3 million people. The mean magnetic flux density for the 60 communities was 5.8 mG. Communities with larger populations generally had higher magnetic flux densities than those with smaller populations.Communities with populations above 100 000, between 50 000 and 100 000, between 10 000 and 50 000, and less than 10 000 had mean magnetic flux densities of 14, 7, 4 and 2.4 mG, respectively. The city of Kingston, population 123 000, had the highest mean magnetic flux density (47 mG) while Burks Falls, population 1000, had the lowest (0.8 mG).Mor...
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A revised version of the storm-time disturbance index Dst is calculated using hourly-mean magnetic-observatory data from four standard observatories and collected over the years 1958–2007. The calculation algorithm is a revision of that established by Sugiura et al., and which is now used by the Kyoto World Data Center for routine production of Dst. The most important new development is for the removal of solar-quiet variation. This is done through time and frequency-domain band-stop filtering – selectively removing specific Fourier terms approximating stationary periodic variation driven by the Earth’s rotation, the Moon’s orbit, the Earth’s orbit around the Sun, and their mutual coupling. The resulting non-stationary...
Electric and magnetic fields were measured during the summer of 1998 in south-central Ontario within the business district of 60 communities, ranging in size from 1000 to 2.3 million people. The mean magnetic flux density for the 60 communities was 5.8 mG. Communities with larger populations generally had higher magnetic flux densities than those with smaller populations.Communities with populations above 100 000, between 50 000 and 100 000, between 10 000 and 50 000, and less than 10 000 had mean magnetic flux densities of 14, 7, 4 and 2.4 mG, respectively. The city of Kingston, population 123 000, had the highest mean magnetic flux density (47 mG) while Burks Falls, population 1000, had the lowest (0.8 mG).Mor...
Environmental pollution has a major effect on human health and other life types. A source of environmental pollution is the magnetic field produced near high and extra high voltage (EHV) transmission lines. Magnetic fields from AC EHV lines have been discussed in this paper. The field profiles and their contribution to environmental pollution are studied, these being under transmission lines with different line system configurations, using the three dimensional approaches. These line system configurations are more commonly used in Egypt and other countries. The obtained results are found to be useful for discussing the comparison of the field densities on the human body and other life types at the ground level under...
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The mission of the U.S. Geological Survey's Geomagnetism Program is to monitor the Earth's magnetic field. Using ground-based observatories, the Program provides continuous records of magnetic field variations covering long timescales; disseminates magnetic data to various governmental, academic, and private institutions; and conducts research into the nature of geomagnetic variations for purposes of scientific understanding and hazard mitigation. The Program is an integral part of the U.S. Government's Space Weather Operations, Research and Mitigation Subcommittee, which also includes programs in the National Aeronautics and Space Administration (NASA), the Department of Defense (DOD), the National Oceanic and...
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Movie-maps of low-latitude horizontal-intensity magnetic disturbance are derived from magnetic vector time series data collected at multiple ground-based observatories. Using a technique similar to that used in the calculation of Dst, a quiet time baseline is subtracted from the time series from each observatory. The remaining disturbance time series are shown in a polar coordinate system that accommodates both Earth rotation and the universal time dependence of magnetospheric disturbance. Each magnetic storm recorded in the movie-maps is different. While some standard interpretations about the storm time equatorial ring current appear to apply to certain moments and certain phases of some storms, the movie-maps...