## 1 Introduction  
The full-scale development of technical infrastructure in the Arctic zone of the Russian Federation is associated with risks arising from the negative influence of space weather (mainly through high-intensity geomagnetic disturbances) on technological systems. Thus, extreme geomagnetic disturbances (GMDs) observed in the auroral and subauroral zones are one of the factors, the neglect of which leads to an increase in the frequency of failures of technical systems in the high-latitude regions, a decrease in the overall level of technosphere safety, and, as a consequence, accidents of various scales. One of the most actively studied manifestations of GMD at high latitudes are geomagnetically induced currents (GICs) excited in spatially distributed conductive technical systems (pipelines, power lines, railway infrastructure facilities, etc.) due to geomagnetic disturbances with the variability dB/dt about several hundreds of nT/min and more. GICs may cause malfunctions and failures of energy, transport, and telecommunication systems. For example, a magnetic storm on 13 March 1989 caused the failure of power transformers and a cascade shutdown (blackout) of electric power transmission lines for more than 9 h in the province of Quebec (Canada) [1]. In the united power system in the northwest of Russia in November 2001, due to the GMA, there were two one-way disconnections of the electric power transmission line (330 kV) \"Olenegorsk-Monchegorsk\",and consumers with a total capacity of more than 70 MW were disconnected [2]. In October 2003, a similar reason caused the 20-50 min power outage in the power system in southern Sweden. The report of \"Zurich Insurance Group\" claims that only in the United States, as a result of electrical failures during the periods of magnetic storms from 2005 to 2015, the insurance payments exceeded $1.9 billion [3]. It was found that practically every strong magnetic storm produced anomalies in the signal automation of the northern branches of the railways \"Oktyabrskaya\" and \"Severnaya\" [4, 5]. Additional information about the effects of the GMA on various technological systems can be found in the review [6]. Besides a decrease in the reliability of terrestrial technical systems, due to a high level of ionospheric plasma turbulence in high-latitude regions, problems with the positioning accuracy and fault tolerance of the global navigation satellite systems (GNSS) GPS and GLONASS may occur [7]. One of the few existing in the world system for the GIC monitoring and research was deployed in 2011 under the project \"EURISGIC FP7-SPACE-2010\". It implements the registration of GIC parameters at four Russian (Vyhodnov, Revda, Titan, Louhi, Kondopoga) and three Finnish (Pirttikoski, Rauma, Yllikkala) transformer substations [8] of electric power transmission 330/440 kV lines. The nearby magnetic stations of the IMAGE array make it possible to record the geomagnetic field variations simultaneously. The prediction of GIC in a technological system during GMD is not a simple problem. For that, at least the knowledge of the GMD spectral and spatial characteristics, topology of the system, and distribution of surface impedances of the underlaying Earth's crust are necessary. Therefore, a more simple and straightforward approach is developing--to construct from previous observational data a statistical model which would predict a probable GIC in a particular system from the data of nearby magnetic stations [9, 10, 11, 12, 13]. However, such a goal has not yet been reached. It remains unclear what geomagnetic indices are most appropriate for the accurate diagnostics of GIC, and what the optimal number of parameters in the models should be taken into account. The choice of criteria based on which one or another source of reference data should be selected is not obvious.