Research of Geomagnetically Induced Currents (GIC) in Finland

"Space Weather" refers to electromagnetic and particle conditions in the near-Earth space that may disturb and damage ground-based and space-borne technological systems. "Geomagnetically induced currents" (GIC) in technological conductor networks, such as electric power transmission grids, oil and gas pipelines, telecommunication cables and railway equipment, are a ground manifestation of space weather. Harmful saturation of transformers may occur in power systems due to GIC, and in pipelines, GIC can create problems associated with corrosion and its control. Although Finland is a high-latitude country, where GIC risks tend to be larger, Finnish systems have practically never experienced GIC problems so far. However, research of GIC including theoretical modelling and measurements in the high-voltage power grid and in the natural gas pipeline has already been done in Finland for about thirty years. The largest GIC value recorded in the Finnish power grid is about 200 A. After a general introduction to GIC, the research carried out in Finland is discussed in this paper.