Space weather events in July 1982 and October 2003 and the effects of geomagnetically induced currents on Swedish technical systems

TLDR

Both events occurred in Sweden during intense space weather storms a few years after the sunspot maximum, and the paper discusses related railway signalling and power network issues. The paper analyzes two notable space weather events—a railway problem in July 1982 and a power blackout in October 2003—and describes the solar and solar wind conditions that led to the ground‑level GIC events. Using modelling techniques from a prior study, the authors calculated the horizontal geoelectric field in southern Sweden and the GIC in the 400 kV power grid during the October 2003 event. The calculated fields and GIC agree with measurements; in July 1982, ΔBx peaked at ~2500 nT/min and the geoelectric field reached several volts per km, while in October 2003, smaller geomagnetic fluctuations produced hundreds of amperes of GIC in the power grid. Abstract.

Abstract

Abstract. In this paper, we analyse in detail two famous space weather events; a railway problem on 13–14 July 1982 and a power blackout on 30 October 2003. Both occurred in Sweden during very intensive space weather storms and each of them a few years after the sunspot maximum. This paper provides a description of the conditions on the Sun and in the solar wind leading to the two GIC events on the ground. By applying modelling techniques introduced and developed in our previous paper, we also calculate the horizontal geoelectric field at the Earth's surface in southern Sweden during the two storms as well as GIC flowing in the southern Swedish 400 kV power grid during the event in October 2003. The results from the calculations agree with all measured data available. In the July-1982 storm, the geomagnetic field variation, ΔBx, reached values up to ~2500 nT/min and the geoelectric field reached values in the order of several volts per kilometer. In the October-2003 storm, the geomagnetic field fluctuations were smaller. However, GIC of some hundreds of amperes flowed in the power grid during the October-2003 event. Technological issues related to the railway signalling in July 1982 and to the power network equipment in October 2003 are also discussed.