The EURISGIC project (European Risk from Geomagnetically Induced Currents) aims at deriving statistics of geomagnetically induced currents (GIC) in the European high-voltage power grids. Such a continent-wide system of more than 1500 substations and transmission lines requires updates of the previous modelling, which has dealt with national grids in fairly small geographic areas. We present here how GIC modelling can be conveniently performed on a spherical surface with minor changes in the previous technique. We derive the exact formulation to calculate geovoltages on the surface of a sphere and show its practical approximation in a fast vectorised form. Using the model of the old Finnish power grid and a much larger prototype model of European high-voltage power grids, we validate the new technique by comparing it to the old one. We also compare model results to measured data in the following cases: geoelectric field at the Nagycenk observatory, Hungary; GIC at a Russian transformer; GIC along the Finnish natural gas pipeline. In all cases, the new method works reasonably well.

Geomagnetically induced currents (GICs) represent a significant challenge for society on a stable electricity supply. Space weather activates global electromagnetic and plasma processes in the near-Earth environment, however, the highest risk of GICs is related not directly to those processes with enormous energy yield, but too much weaker, but fast, processes. Here we consider several typical examples of such fast processes and their impact on power transmission lines in the Kola Peninsula and in Karelia: interplanetary shocks; traveling convection vortices; impulses embedded in substorms; and irregular Pi3 pulsations. Geomagnetic field variability is examined using data from the IMAGE (International Monitor for Auroral Geomagnetic Effects) magnetometer array. We have confirmed that during the considered impulsive events the ionospheric currents fluctuate in both the East-West and North-South directions, and they do induce GIC in latitudinally extended electric power line. It is important to reveal the fine structure of fast geomagnetic variations during storms and substorms not only for a practical point of view but also for a fundamental scientific view.

The strongest event of geomagnetically induced currents (GIC) detected by the North‐West Russian GIC network occurred during the main phase of the magnetic storm on 28 and 29 June 2013. Extremely high value, 120 A, was recorded in the 330 kV transformers on Kola Peninsula in the 04–07 magnetic local time (MLT) sector. The Defense Meteorological Satellite Program (DMSP) spacecraft took a sequence of ultraviolet (UV) auroral images in the southern hemisphere and observed multiple omega bands. The ionospheric equivalent electric currents based on the International Monitor for Auroral Geomagnetic Effects (IMAGE) magnetometer network reveal a sequence of current vortex pairs moving eastward with the speed of 0.5–2.5 km/s that fits to the electrodynamics scheme of omega bands. Although the temporal variations of the associated current system are slow, the omega bands can be responsible for strong magnetic variations and GIC due to fast propagations of currents in the azimuthal direction.

The St. Patrick's Day geomagnetic storm on March 17, 2015, has been chosen by the space community for synergetic analysis to build a more comprehensive picture of the storm's origin and evolution. This storm had an unusually long (~ 17 h) main phase. During this period, many substorm-like activations occurred. These activations resulted in bursts of geomagnetically induced currents (GICs) in power lines on the Kola peninsula. To examine the substorm activations in more detail, we apply various data processing techniques for the worldwide array of magnetometers: the virtual magnetograms, magnetic latitude-local time (MLT) snapshots, and magnetic keograms. These techniques are simple tools that are supplementary to more advanced facilities developed for the analysis of SuperDARN, IMAGE, and CARISMA arrays. We compare the global spatial localization and time evolution of the geomagnetic X-component disturbance and magnetic field variability measured by the Hilbert transform of time derivative dB/dt. The latitude-MLT mapping of these magnitudes shows that very often a region with highest magnetic variability does not overlap with a substorm "epicenter" but is shifted to its poleward or equatorward boundaries. Highest variability of the geomagnetic field, and consequently intense GICs, are caused by medium-scale fast varying structures. There is no one-to-one correspondence between substorm intensity and GIC magnitude.

<p>The strongest event of geomagnetically induced currents (GIC) detected by the North-West Russian GIC network occurred during the main phase of the magnetic storm on June 28-29, 2013. Extremely high values, 120 A, were recorded in the 330 kV transformers on Kola Peninsula in the 04--07 magnetic local time (MLT) sector. The Defense Meteorological Satellite Program (DMSP) spacecraft took a sequence of ultraviolet (UV) auroral images in the southern hemisphere and observed multiple omega bands. The ionospheric equivalent electric currents based on the International Monitor for Auroral Geomagnetic Effects (IMAGE) magnetometer network reveal a sequence of current vortex pairs moving eastward with the speed of 0.5-2.5 km/s, that fits to the electrodynamics scheme of omega bands. Although the temporal variations of the associated current system are slow, the omega bands can be responsible for strong magnetic variations and GIC due to fast propagations of currents in the azimuthal direction.  The first steps towards the statistica study of the highest GIC recorded at Vykhodnoy transformer show that about 50% of events have properties similar to the comprehensively studied 29 June 2013 case.</p>