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

2019 ◽  
Vol 115 (1/2) ◽  
Author(s):  
Emmanuel Nahayo ◽  
Pieter B. Kotzé ◽  
Pierre J. Cilliers ◽  
Stefan Lotz

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.

2013 ◽  
Vol 8 (S300) ◽  
pp. 500-501
Author(s):  
Larisa Trichtchenko

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.


2021 ◽  
Author(s):  
Larisa Trichtchenko

<p>Geomagnetically induced currents (GIC), increased during space weather events, are able to interfere with pipeline corrosion protections systems and potentially can increase corrosion of the pipeline steel.</p><p>Methods, widely used for the evaluation of annual corrosion rates, are based on exposure of steel to constant currents and voltages (DC), or alternating currents and voltages of a constant frequency (50 Hz or 60 Hz), while GIC are characterised by a continuous frequency spectrum, with the range of frequencies from 10<sup>-5</sup> Hz to 1 Hz.</p><p>This paper introduces the methods for use in the estimation of corrosion rates on pipeline steel produced by GIC (commonly referred to as “telluric currents” in the pipeline industry) and provides results calculated for specific time periods with use of available recordings made on pipelines at the times of geomagnetic storms. As well, annual cumulative corrosion rates are estimated based on the modelling of pipeline currents and voltages.</p><p>In addition to the detailed presentation of the methods utilised, a comparison of corrosion rates produced by telluric variations on non-protected and protected pipelines located in mid- and high-latitudes is presented.</p>


2021 ◽  
Author(s):  
Andrew Dimmock ◽  
Lisa Rosenqvist ◽  
Ari Viljanen ◽  
Colin Forsyth ◽  
Mervyn Freeman ◽  
...  

<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>


2018 ◽  
Vol 8 ◽  
pp. A03 ◽  
Author(s):  
Roberta Piccinelli ◽  
Elisabeth Krausmann

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.


2016 ◽  
Vol 34 (4) ◽  
pp. 427-436 ◽  
Author(s):  
Larisa Trichtchenko

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.


2020 ◽  
Vol 38 (4) ◽  
pp. 881-888
Author(s):  
Joyrles Fernandes de Moraes ◽  
Igo Paulino ◽  
Lívia R. Alves ◽  
Clezio Marcos Denardini

Abstract. The electric field induced in the Bolivia–Brazil gas pipeline (GASBOL) was calculated by using the distributed source line transmission (DSLT) theory during several space weather events. We used geomagnetic data collected by a fluxgate magnetometer located at São José dos Campos (23.2∘ S, 45.9∘ W). The total corrosion rate was calculated by using the Gummow (2002) methodology and was based on the assumption of a 1 cm hole in the coating of the pipeline. The calculations were performed at the ends of pipeline where the largest “out-of-phase” pipe-to-soil potential (PSP) variations were obtained. The variations in PSP during the 17 March 2015 geomagnetic storm have led to the greatest corrosion rate of the analyzed events. All the space weather events evaluated with high terminating impedance may have contributed to increases in the corrosion process. The applied technique can be used to evaluate the corrosion rate due to the high telluric activity associated with the geomagnetic storms at specific locations.


Space Weather ◽  
2020 ◽  
Vol 18 (8) ◽  
Author(s):  
J. J. Zhang ◽  
Y. Q. Yu ◽  
C. Wang ◽  
D. Du ◽  
D. Wei ◽  
...  

2016 ◽  
Vol 12 (S328) ◽  
pp. 315-328
Author(s):  
Vladimir S. Airapetian

AbstractOur Sun, a magnetically mild star, exhibits space weather in the form of magnetically driven solar explosive events (SEE) including solar flares, coronal mass ejections and energetic particle events. We use Kepler data and reconstruction of X-ray and UV emission from young solar-like stars to recover the frequency and energy fluxes from extreme events from active stars including the young Sun. Extreme SEEs from a magnetically active young Sun could significantly perturb the young Earth's magnetosphere, cause strong geomagnetic storms, initiate escape and introduce chemical changes in its lower atmosphere. I present our recent simulations results based on multi-dimensional multi-fluid hydrodynamic and magnetohydrodynamic models of interactions of extreme CME and SEP events with magnetospheres and lower atmospheres of early Earth and exoplanets around active stars. We also discuss the implications of the impact of these effects on evolving habitability conditions of the early Earth and prebiotic chemistry introduced by space weather events at the early phase of evolution of our Sun.


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