Studies of space weather effects on the finnish natural gas pipeline and on the finnish high-voltage power system

Abstract

Geomagnetically induced currents (GIC) in technological systems are the ground end of the complicated space weather chain. GIC are a possible source of problems to the systems. In power networks, GIC cause saturation of transformers, which may even result in a collapse of the whole system and in damage of transformers. Pipelines can suffer from problems associated with corrosion and its control. The Finnish high-voltage power grid and the Finnish natural gas pipeline have not encountered GIC harm but due to the high-latitude location of the country and to a general interest in phenomena in the auroral region, an active research of the occurrence of GIC in these systems has been continued for about twenty years. The studies carried out have contained both GIC measurements and theoretical modelling, partly based on geomagnetic data. Estimates of expectable GIC magnitudes at different sites of the systems have been derived. However, GIC values greatly depend on the network configuration, so GIC estimates need not be valid after changes in the configuration. The electric field at the Earth's surface is the key parameter when calculating GIC in a network as it is not affected by network configuration changes. Future efforts in investigations of GIC will be focused on understanding ionospheric and magnetospheric processes responsible for large GIC events.