SWWT Topical Group "Ground Effects"


At the Earth’s surface, space weather manifests itself as increased geomagnetic activity and geoelectromagnetic effects.

The induced geoelectric field drives currents, called geomagnetically induced currents (GIC), in man-made conductors, such as electric power transmission systems, oil and gas pipelines, telecommunication cables and railway equipment.

GIC may cause problems to the systems: transformers can be saturated, pipelines may suffer from enhanced corrosion, and telecommunication and railway systems can experience overvoltage.

Mission Statement

The Ground Effects Topical Group (GETG) cover a wide range of activities:

  • Modelling the occurrence of geomagnetic variations and geoelectric fields during space weather events.
  • Modelling GIC in electric power systems (discrete grounding).
  • Modelling GIC in buried pipeline networks (continuous grounding).
  • Measurements of geomagnetic variations, geoelectric fields and GIC.
  • Development of forecast techniques of geomagnetic storms and GIC based on neural networks and physical models.
  • Risks and Hazards from an insurance and social perspective.
  • Public outreach.



Dr Ari Viljanen
Finnish Meteorological Institute
P.O. Box 503
FIN-00101 Helsinki

Do you want to join the GETG and become an active member? Then you should be connected to the work or research that is carried out within the GETG. Please state your occupation (scientist/engineer/other), your current work/research and why you want to join the ground effects topical group.

Send your enquiry to: ari.viljanen (at) fmi.fi


Next GETG meeting will be held during ESWW9 in Brussels, Belgium, on 8 November, 2012.

The ESWW GIC user’s lunch was held in Namur, Belgium, on 30 November, 2011. This was a successful workshop with almost 30 participants from the scientific community, the industry, goverments, agencies, etc. The report of this meeting can be found here.

Related Activities

    European Risk from Geomagnetically Induced Currents - An EU/FP7 funded project that will produce the first European-wide real-time prototype forecast service of GIC in power systems.
    Coordinator: Ari Viljanen (FMI)

Past Meetings

  • Eighth European Space Weather Week, November 28 - December 02, 2011, Namur, Belgium (Report)
  • Seventh European Space Weather Week, 15-19 November, 2010, Brugge, Belgium
  • Sixth European Space Weather Week, 16-20 November, 2009, Brugge, Belgium
  • Fifth European Space Weather Week, 17-21 November, 2008, Brussels, Belgium
  • Fourth European Space Weather Week, 5-9 November, 2007, Brussels, Belgium
  • Third European Space Weather Week, 13-17 November, 2006, Brussels, Belgium