The quantification and possible sources of spatially structured and large amplitude geomagnetic depressions during strong geomagnetic storms measured by IMAGE

<p>Geomagnetically Induced Currents (GICs) are a space weather hazard that can negatively impact large ground-based infrastructures such as power lines, pipelines, and railways. They are driven by the dynamic spatiotemporal behaviour of currents flowing in geospace, which drive rapid geomagnetic disturbances on the ground. In some cases, geomagnetic disturbances are highly localised and spatially structured due to the dynamical behaviour of geospace currents and magnetosphere-ionosphere (M-I) coupling dynamics, which are complex and often unclear.</p><p>In this work, we investigate and quantify the spatial structure of large geomagnetic depressions exceeding several hundred nT according to the 10 strongest events measured over Fennoscandia by IMAGE. Using ground magnetometer measurements we connect these spatially structured geomagnetic disturbances to possible M-I coupling processes and identify their likely magnetospheric origin. In addition, the ability for these disturbances to drive large GICs is assessed by calculating their respective geoelectric fields in Sweden using the SMAP ground conductivity model. To compliment the observations, we also utilise high resolution runs (>7 million cells) of the Space Weather Modeling Framework (SWMF) to determine to what extent global MHD models can capture this behaviour.</p>

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From solar eruption to transformer saturation: the space weather chain

Proceedings of the International Astronomical Union ◽

10.1017/s1743921313011733 ◽

2013 ◽

Vol 8 (S300) ◽

pp. 500-501

Author(s):

Larisa Trichtchenko

Keyword(s):

Space Weather ◽

Geomagnetic Field ◽

Geomagnetic Storms ◽

Interplanetary Medium ◽

Practical Importance ◽

Power Grids ◽

Geomagnetically Induced Currents ◽

Large Space ◽

Weather Events ◽

Induced Currents

AbstractCoronal mass ejections (CME) and associated interplanetary-propagated solar wind disturbances are the established causes of the geomagnetic storms which, in turn, create the most hazardous impacts on power grids. These impacts are due to the large geomagnetically induced currents (GIC) associated with variations of geomagnetic field during storms, which, flowing through the transformer windings, cause extra magnetisation. That can lead to transformer saturation and, in extreme cases, can result in power blackouts. Thus, it is of practical importance to study the solar causes of the large space weather events. This paper presents the example of the space weather chain for the event of 5-6 November 2001 and a table providing complete overview of the largest solar events during solar cycle 23 with their subsequent effects on interplanetary medium and on the ground. This compact overview can be used as guidance for investigations of the solar causes and their predictions, which has a practical importance in everyday life.

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Observations from SANSA’s geomagnetic network during the Saint Patrick’s Day storm of 17–18 March 2015

South African Journal of Science ◽

10.17159/sajs.2019/5204 ◽

2019 ◽

Vol 115 (1/2) ◽

Cited By ~ 1

Author(s):

Emmanuel Nahayo ◽

Pieter B. Kotzé ◽

Pierre J. Cilliers ◽

Stefan Lotz

Keyword(s):

Electric Field ◽

Space Weather ◽

Power Distribution ◽

Geomagnetic Storms ◽

Geomagnetically Induced Currents ◽

Weather Events ◽

Induced Currents ◽

Temporary Disturbance ◽

Global And Local ◽

Magnetic Observatories

Geomagnetic storms are space weather events that result in a temporary disturbance of the earth’s magnetosphere caused by a solar wind that interacts with the earth’s magnetic field. We examined more closely how some southern African magnetic observatories responded to the Saint Patrick’s Day storm using local K-indices. We show how this network of observatories may be utilised to model induced electric field, which is useful for the monitoring of geomagnetically induced anomalous currents capable of damaging power distribution infrastructure. We show an example of the correlation between a modelled induced electric field and measured geomagnetically induced currents in southern Africa. The data show that there are differences between global and local indices, which vary with the phases of the storm. We show the latitude dependence of geomagnetic activity and demonstrate that the direction of the variation is different for the X and Y components. Significance: • The importance of ground-based data in space weather studies is demonstrated. • We show how SANSA’s geomagnetic network may be utilised to model induced electric field, which is useful for the monitoring of geomagnetically induced anomalous currents capable of damaging power distribution infrastructure.

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North Europe power transmission system vulnerability during extreme space weather

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2017033 ◽

2018 ◽

Vol 8 ◽

pp. A03 ◽

Cited By ~ 2

Author(s):

Roberta Piccinelli ◽

Elisabeth Krausmann

Keyword(s):

Space Weather ◽

Power Transmission ◽

Geomagnetic Storms ◽

Extreme Event ◽

Transmission System ◽

Mitigation Measures ◽

Geomagnetically Induced Currents ◽

Power Transmission System ◽

Induced Currents ◽

The Impact

Space weather driven by solar activity can induce geomagnetic disturbances at the Earth's surface that can affect power transmission systems. Variations in the geomagnetic field result in geomagnetically induced currents that can enter the system through its grounding connections, saturate transformers and lead to system instability and possibly collapse. This study analyzes the impact of extreme space weather on the northern part of the European power transmission grid for different transformer designs to understand its vulnerability in case of an extreme event. The behavior of the system was analyzed in its operational mode during a severe geomagnetic storm, and mitigation measures, like line compensation, were also considered. These measures change the topology of the system, thus varying the path of geomagnetically induced currents and inducing a local imbalance in the voltage stability superimposed on the grid operational flow. Our analysis shows that the North European power transmission system is fairly robust against extreme space weather events. When considering transformers more vulnerable to geomagnetic storms, only few episodes of instability were found in correspondence with an existing voltage instability due to the underlying system load. The presence of mitigation measures limited the areas of the network in which bus voltage instabilities arise with respect to the system in which mitigation measures are absent.

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Validating the Space Weather Modeling Framework (SWMF) for applications in northern Europe

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2020034 ◽

2020 ◽

Vol 10 ◽

pp. 33

Author(s):

Norah Kaggwa Kwagala ◽

Michael Hesse ◽

Therese Moretto ◽

Paul Tenfjord ◽

Cecilia Norgren ◽

...

Keyword(s):

Space Weather ◽

Geomagnetic Storms ◽

Skill Score ◽

Probability Of Detection ◽

Rate Of Change ◽

Local Times ◽

False Detection ◽

Modeling Framework ◽

Heidke Skill Score ◽

Weather Modeling

In this study we investigate the performance of the University of Michigan’s Space Weather Modeling Framework (SWMF) in prediction of ground magnetic perturbations (ΔB) and their rate of change with time (dB/dt), which is directly connected to geomagnetically induced currents (GICs). We use the SWMF set-up where the global magnetosphere provided by the Block Adaptive Tree Solar-wind Roe-type Upwind Scheme (BATS-R-US) MHD code, is coupled to the inner magnetosphere and the ionospheric electrodynamics. The validation is done for ΔB and dB/dt separately. The performance is evaluated via data-model comparison through a metrics-based approach. For ΔB, the normalized root mean square error (nRMS) and the correlation coefficient are used. For dB/dt, the probability of detection, the probability of false detection, the Heidke skill score, and the frequency bias are used for different dB/dt thresholds. The performance is evaluated for eleven ground magnetometer stations located between 59° and 85° magnetic latitude and spanning about five magnetic local times. Eight geomagnetic storms are studied. Our results show that the SWMF predicts the northward component of the perturbations better at lower latitudes (59°–67°) than at higher latitudes (>67°), whereas for the eastward component, the model performs better at high latitudes. Generally, the SWMF performs well in the prediction of dB/dt for a 0.3 nT/s threshold, with a high probability of detection ≈0.8, low probability of false detection (<0.4), and Heidke skill score above zero. To a large extent the model tends to predict events as often as they are actually occurring in nature (frequency bias 1). With respect to the metrics measures, the dB/dt prediction performance generally decreases as the threshold is raised, except for the probability of false detection, which improves.

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Modulation of the Power Transformer Magnetizing Inductance by Variations of Geomagnetically Induced Currents during Geomagnetic Disturbances

10.1109/uralcon52005.2021.9559580 ◽

2021 ◽

Author(s):

Vera V. Vakhnina ◽

Aleksey A. Kuvshinov ◽

Aleksey N. Chernenko

Keyword(s):

Power Transformer ◽

Geomagnetically Induced Currents ◽

Geomagnetic Disturbances ◽

Induced Currents

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Modelling natural electromagnetic interference in man-made conductors for space weather applications

Annales Geophysicae ◽

10.5194/angeo-34-427-2016 ◽

2016 ◽

Vol 34 (4) ◽

pp. 427-436 ◽

Cited By ~ 2

Author(s):

Larisa Trichtchenko

Keyword(s):

Exact Solution ◽

Space Weather ◽

Electromagnetic Interference ◽

Geomagnetic Storms ◽

Electromagnetic Properties ◽

Electromagnetic Response ◽

Frequency Range ◽

Geomagnetically Induced Currents ◽

Geomagnetic Variations ◽

Wide Range

Abstract. Power transmission lines above the ground, cables and pipelines in the ground and under the sea, and in general all man-made long grounded conductors are exposed to the variations of the natural electromagnetic field. The resulting currents in the networks (commonly named geomagnetically induced currents, GIC), are produced by the conductive and/or inductive coupling and can compromise or even disrupt system operations and, in extreme cases, cause power blackouts, railway signalling mis-operation, or interfere with pipeline corrosion protection systems. To properly model the GIC in order to mitigate their impacts it is necessary to know the frequency dependence of the response of these systems to the geomagnetic variations which naturally span a wide frequency range. For that, the general equations of the electromagnetic induction in a multi-layered infinitely long cylinder (representing cable, power line wire, rail or pipeline) embedded in uniform media have been solved utilising methods widely used in geophysics. The derived electromagnetic fields and currents include the effects of the electromagnetic properties of each layer and of the different types of the surrounding media. This exact solution then has been used to examine the electromagnetic response of particular samples of long conducting structures to the external electromagnetic wave for a wide range of frequencies. Because the exact solution has a rather complicated structure, simple approximate analytical formulas have been proposed, analysed and compared with the results from the exact model. These approximate formulas show good coincidence in the frequency range spanning from geomagnetic storms (less than mHz) to pulsations (mHz to Hz) to atmospherics (kHz) and above, and can be recommended for use in space weather applications.

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