Researchers at the University of Leicester, Lancaster University and St Petersburg State Universi... more Researchers at the University of Leicester, Lancaster University and St Petersburg State University have developed various models that can be employed in HF radio propagation predictions. Signal coverage predictions make use of numerical ray tracing to estimate the ray paths through a model ionosphere that includes various ionospheric features prevalent at high latitudes (in particular patches, arcs, ionisation tongue, auroral zone irregularities and the mid-latitude trough). Modelling of D-region absorption is also included. GOES satellites provide information on X-ray flux (causing shortwave fadeout during solar flares) and precipitating energetic proton flux which correlates strongly with Polar Cap Absorption (PCA). Solar wind and interplanetary magnetic field measurements from the ACE or DSCOVR spacecraft provide geomagnetic index estimates used to model the location of both auroral absorption and the proton rigidity cutoff boundary that defines the latitudinal extent of PCA dur...
Disturbances of the geomagnetic field produced by space weather events can have an impact on powe... more Disturbances of the geomagnetic field produced by space weather events can have an impact on power systems and other critical infrastructure. To mitigate these risks it is important to determine the extreme values of geomagnetic activity that can occur. More than 40 years of 1 min magnetic data recorded at 13 Canadian geomagnetic observatories have been analyzed to evaluate extreme levels in geomagnetic and geoelectric activities in different locations of Canada. The hourly ranges of geomagnetic field variations and hourly maximum in rate of change of the magnetic variations have been used as measures of geomagnetic activity. Geoelectric activity is estimated by the hourly peak amplitude of the geoelectric fields calculated with the use of Earth resistivity models specified for different locations in Canada. A generalized extreme value distribution was applied to geomagnetic and geoelectric indices to evaluate extreme geomagnetic and geoelectric disturbances, which could happen once...
The outer radiation belt injection, transport, acceleration and loss satellite (ORBITALS) is a sm... more The outer radiation belt injection, transport, acceleration and loss satellite (ORBITALS) is a small satellite mission proposed as a Canadian contribution to the satellite infrastructure for the International Living With a Star (ILWS) program. The ORBITALS will monitor the energetic electron and ion populations in the inner magnetosphere across a wide range of energies (keV to tens of MeV) as
Space weather storms involve intense and rapidly varying electric currents in the ionosphere, whi... more Space weather storms involve intense and rapidly varying electric currents in the ionosphere, which create electric and magnetic fields at the Earth's surface. The electric fields drive geomagnetically induced currents (GIC) in technological networks and may have serious impacts. For assessing the hazards it is necessary to estimate GIC magnitudes, and this requires calculations of the electric and magnetic fields produced at the Earth's surface by the ionospheric currents. The surface fields are also affected by currents induced within the ground and influenced by the conductivity of the Earth. This also has to be taken into account. The calculation methods should be fast enough that they can be applied to forecasting the fields and GIC, for example, by using satellite observations of the solar wind. In this paper, we consider an infinitely long horizontal line current, which is the basic model of an auroral electrojet and simple enough to give insight into the physics and ...
2007 7th International Symposium on Electromagnetic Compatibility and Electromagnetic Ecology, 2007
Page 1. EFFECTS OF RECENT GEOM AGNETIC STORM S ON POW ER SYSTEM S ... Fig. 1a is representing the... more Page 1. EFFECTS OF RECENT GEOM AGNETIC STORM S ON POW ER SYSTEM S ... Fig. 1a is representing the image of the major solar source of the ground magnetic storms, a full halo coronal mass ejection (CME) which occurred on October 28. ...
2013 IEEE Power & Energy Society General Meeting, 2013
ABSTRACT Geomagnetically induced currents (GIC) can pose a problem for power system operation. To... more ABSTRACT Geomagnetically induced currents (GIC) can pose a problem for power system operation. To assess the geomagnetic threat requires modelling of the GIC in the power system. However, as well as the characteristics of the system itself, GIC are affected by connections to neighbouring systems. This paper considers three choices of equivalent circuit for a neighbouring system. Model calculations are made for the Ontario system with equivalent circuits for the neighbouring Manitoba system, and vice versa. Values from these calculations are compared with the exact values determined from model calculations for the combined Ontario and Manitoba systems. The calculations with equivalent circuits produce errors in the GIC at substations that diminish with increasing distance of the substation from the connection to the neighbour. Comparison of the results showed that the best choice for an equivalent circuit comprises the induced voltage and resistance for the first transmission line into the neighbouring system.
Researchers at the University of Leicester, Lancaster University and St Petersburg State Universi... more Researchers at the University of Leicester, Lancaster University and St Petersburg State University have developed various models that can be employed in HF radio propagation predictions. Signal coverage predictions make use of numerical ray tracing to estimate the ray paths through a model ionosphere that includes various ionospheric features prevalent at high latitudes (in particular patches, arcs, ionisation tongue, auroral zone irregularities and the mid-latitude trough). Modelling of D-region absorption is also included. GOES satellites provide information on X-ray flux (causing shortwave fadeout during solar flares) and precipitating energetic proton flux which correlates strongly with Polar Cap Absorption (PCA). Solar wind and interplanetary magnetic field measurements from the ACE or DSCOVR spacecraft provide geomagnetic index estimates used to model the location of both auroral absorption and the proton rigidity cutoff boundary that defines the latitudinal extent of PCA dur...
Disturbances of the geomagnetic field produced by space weather events can have an impact on powe... more Disturbances of the geomagnetic field produced by space weather events can have an impact on power systems and other critical infrastructure. To mitigate these risks it is important to determine the extreme values of geomagnetic activity that can occur. More than 40 years of 1 min magnetic data recorded at 13 Canadian geomagnetic observatories have been analyzed to evaluate extreme levels in geomagnetic and geoelectric activities in different locations of Canada. The hourly ranges of geomagnetic field variations and hourly maximum in rate of change of the magnetic variations have been used as measures of geomagnetic activity. Geoelectric activity is estimated by the hourly peak amplitude of the geoelectric fields calculated with the use of Earth resistivity models specified for different locations in Canada. A generalized extreme value distribution was applied to geomagnetic and geoelectric indices to evaluate extreme geomagnetic and geoelectric disturbances, which could happen once...
The outer radiation belt injection, transport, acceleration and loss satellite (ORBITALS) is a sm... more The outer radiation belt injection, transport, acceleration and loss satellite (ORBITALS) is a small satellite mission proposed as a Canadian contribution to the satellite infrastructure for the International Living With a Star (ILWS) program. The ORBITALS will monitor the energetic electron and ion populations in the inner magnetosphere across a wide range of energies (keV to tens of MeV) as
Space weather storms involve intense and rapidly varying electric currents in the ionosphere, whi... more Space weather storms involve intense and rapidly varying electric currents in the ionosphere, which create electric and magnetic fields at the Earth's surface. The electric fields drive geomagnetically induced currents (GIC) in technological networks and may have serious impacts. For assessing the hazards it is necessary to estimate GIC magnitudes, and this requires calculations of the electric and magnetic fields produced at the Earth's surface by the ionospheric currents. The surface fields are also affected by currents induced within the ground and influenced by the conductivity of the Earth. This also has to be taken into account. The calculation methods should be fast enough that they can be applied to forecasting the fields and GIC, for example, by using satellite observations of the solar wind. In this paper, we consider an infinitely long horizontal line current, which is the basic model of an auroral electrojet and simple enough to give insight into the physics and ...
2007 7th International Symposium on Electromagnetic Compatibility and Electromagnetic Ecology, 2007
Page 1. EFFECTS OF RECENT GEOM AGNETIC STORM S ON POW ER SYSTEM S ... Fig. 1a is representing the... more Page 1. EFFECTS OF RECENT GEOM AGNETIC STORM S ON POW ER SYSTEM S ... Fig. 1a is representing the image of the major solar source of the ground magnetic storms, a full halo coronal mass ejection (CME) which occurred on October 28. ...
2013 IEEE Power & Energy Society General Meeting, 2013
ABSTRACT Geomagnetically induced currents (GIC) can pose a problem for power system operation. To... more ABSTRACT Geomagnetically induced currents (GIC) can pose a problem for power system operation. To assess the geomagnetic threat requires modelling of the GIC in the power system. However, as well as the characteristics of the system itself, GIC are affected by connections to neighbouring systems. This paper considers three choices of equivalent circuit for a neighbouring system. Model calculations are made for the Ontario system with equivalent circuits for the neighbouring Manitoba system, and vice versa. Values from these calculations are compared with the exact values determined from model calculations for the combined Ontario and Manitoba systems. The calculations with equivalent circuits produce errors in the GIC at substations that diminish with increasing distance of the substation from the connection to the neighbour. Comparison of the results showed that the best choice for an equivalent circuit comprises the induced voltage and resistance for the first transmission line into the neighbouring system.
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Papers by David Boteler