Surface electric fields and geomagnetically induced currents in the Scottish Power grid during the 30 October 2003 geomagnetic storm

Abstract. Geomagnetically induced currents (GICs) are directly described by ground electric fields, but estimating them is time-consuming and requires knowledge of the ionospheric currents and the three-dimensional (3D) distribution of the electrical conductivity of the Earth. The time derivative of the horizontal component of the ground magnetic field (dH∕dt) is closely related to the electric field via Faraday's law and provides a convenient proxy for the GIC risk. However, forecasting dH∕dt still remains a challenge. We use 25 years of 10 s data from the northern European International Monitor for Auroral Geomagnetic Effects (IMAGE) magnetometer network to show that part of this problem stems from the fact that, instead of the primary ionospheric currents, the measured dH∕dt is dominated by the signature from the secondary induced telluric currents at nearly all IMAGE stations. The largest effects due to telluric currents occur at coastal sites close to high-conducting ocean water and close to near-surface conductivity anomalies. The secondary magnetic field contribution to the total field is a few tens of percent, in accordance with earlier studies. Our results have been derived using IMAGE data and are thus only valid for the stations involved. However, it is likely that the main principle also applies to other areas. Consequently, it is recommended that the field separation into internal (telluric) and external (ionospheric and magnetospheric) parts is performed whenever feasible (i.e., a dense observation network is available).

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Prediction of geomagnetically induced currents (GICs) flowing in Japanese power grid for Carrington-class magnetic storms

Earth Planets and Space ◽

10.1186/s40623-021-01493-2 ◽

2021 ◽

Vol 73 (1) ◽

Author(s):

Yusuke Ebihara ◽

Shinichi Watari ◽

Sandeep Kumar

Keyword(s):

Transmission Lines ◽

Power Grid ◽

Magnetic Storms ◽

Power Grids ◽

Geomagnetically Induced Currents ◽

Geomagnetic Disturbances ◽

Low Latitude ◽

Solar Eruptions ◽

Induced Currents ◽

Extra High Voltage

AbstractLarge-amplitude geomagnetically induced currents (GICs) are the natural consequences of the solar–terrestrial connection triggered by solar eruptions. The threat of severe damage of power grids due to the GICs is a major concern, in particular, at high latitudes, but is not well understood as for low-latitude power grids. The purpose of this study is to evaluate the lower limit of the GICs that could flow in the Japanese power grid against a Carrington-class severe magnetic storm. On the basis of the geomagnetic disturbances (GMDs) observed at Colaba, India, during the Carrington event in 1859, we calculated the geoelectric disturbances (GEDs) by a convolution theory, and calculated GICs flowing through transformers at 3 substations in the Japanese extra-high-voltage (500-kV) power grid by a linear combination of the GEDs. The estimated GEDs could reach ~ 2.5 V/km at Kakioka, and the GICs could reach, at least, 89 ± 30 A near the storm maximum. These values are several times larger than those estimated for the 13–14 March 1989 storm (in which power blackout occurred in Canada), and the 29–31 October 2003 storm (in which power blackout occurred in Sweden). The GICs estimated here are the lower limits, and there is a probability of stronger GICs at other substations. The method introduced here will be immediately applicable for benchmark evaluation of low-latitude GICs against the Carrington-class magnetic storms if one assumes electrical parameters, such as resistance of transmission lines, with sufficient accuracy.

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April 2000 geomagnetic storm: ionospheric drivers of large geomagnetically induced currents

Annales Geophysicae ◽

10.5194/angeo-21-709-2003 ◽

2003 ◽

Vol 21 (3) ◽

pp. 709-717 ◽

Cited By ~ 39

Author(s):

A. Pulkkinen ◽

A. Thomson ◽

E. Clarke ◽

A. McKay

Keyword(s):

Geomagnetic Storm ◽

Large Scale ◽

Regional Scale ◽

Normal Operation ◽

Technological Systems ◽

Geomagnetically Induced Currents ◽

Ionospheric Currents ◽

Ionospheric Current ◽

Induced Currents ◽

Current Systems

Abstract. Geomagnetically induced currents (GIC) flowing in technological systems on the ground are a direct manifestation of space weather. Due to the proximity of very dynamic ionospheric current systems, GIC are of special interest at high latitudes, where they have been known to cause problems, for example, for normal operation of power transmission systems and buried pipelines. The basic physics underlying GIC, i.e. the magnetosphere – ionosphere interaction and electromagnetic induction in the ground, is already quite well known. However, no detailed study of the drivers of GIC has been carried out and little is known about the relative importance of different types of ionospheric current systems in terms of large GIC. In this study, the geomagnetic storm of 6–7 April 2000 is investigated. During this event, large GIC were measured in technological systems, both in Finland and in Great Britain. Therefore, this provides a basis for a detailed GIC study over a relatively large regional scale. By using GIC data and corresponding geomagnetic data from north European magnetometer networks, the ionospheric drivers of large GIC during the event were identified and analysed. Although most of the peak GIC during the storm were clearly related to substorm intensifications, there were no common characteristics discernible in substorm behaviour that could be associated with all the GIC peaks. For example, both very localized ionospheric currents structures, as well as relatively large-scale propagating structures were observed during the peaks in GIC. Only during the storm sudden commencement at the beginning of the event were large-scale GIC evident across northern Europe with coherent behaviour. The typical duration of peaks in GIC was also quite short, varying between 2–15 min.Key words. Geomagnetism and paleo-magnetism (geomagnetic induction) – Ionosphere (ionospheric disturbances) – Magnetospheric physics (storms and substorms)

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Power Grid Sensitivity Analysis of Geomagnetically Induced Currents

IEEE Transactions on Power Systems ◽

10.1109/tpwrs.2013.2274624 ◽

2013 ◽

Vol 28 (4) ◽

pp. 4821-4828 ◽

Cited By ~ 38

Author(s):

Thomas J. Overbye ◽

Komal S. Shetye ◽

Trevor R. Hutchins ◽

Qun Qiu ◽

James D. Weber

Keyword(s):

Sensitivity Analysis ◽

Power Grid ◽

Geomagnetically Induced Currents ◽

Induced Currents

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On the flow of geomagnetically induced currents in an electric power transmission network

Canadian Journal of Physics ◽

10.1139/p10-028 ◽

2010 ◽

Vol 88 (5) ◽

pp. 357-363 ◽

Cited By ~ 4

Author(s):

Risto J. Pirjola

Keyword(s):

Electric Power ◽

Power Transmission ◽

Power Grid ◽

Space Physics ◽

Practical Significance ◽

Test Model ◽

Geomagnetically Induced Currents ◽

Geophysical Research ◽

Model Calculations ◽

Induced Currents

Geomagnetically induced currents (GICs) in conductor networks are among the ground-level effects of space weather. GICs are a possible source of problems to the system. Today, electric power transmission grids are the most important concern regarding GICs, which may in the worst cases lead to blackouts in large areas and permanent damage to transformers. The evaluation of GIC risks and the design of possible countermeasures require estimation of expected GIC magnitudes in transformers. This can be achieved by model calculations supplemented by GIC recordings at some sites. Although in principle GICs can flow all over a large galvanically-connected power grid, which should thus be included as a whole in a GIC calculation, the network must usually be restricted somehow in practical computations of GICs. By using a power grid test model, this paper provides a systematic numerical investigation showing that GICs do not flow over very long distances in a power grid, which is a good result and justifies the neglect of the parts of the network that lie far away from the area of primary interest. Besides practical significance in electric power engineering, studies of GICs can be used for space physics and geophysical research as well. It is also important to understand the features of the flow pattern of GICs in a network.

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