GIC Services

Rapid variations of the geomagnetic field, caused by space weather, produce an electric field in the Earth's surface. This electric field is the source of electrical currents - called Geomagnetically Induced Currents or GIC - that can, for example, cause damage to transformers in the power grid and cause corrosion to pipelines.

B_GIC - index for GIC studies

At BGS we monitor the geomagnetic field to provide near-real-time information about GIC and the risk to ground based technology. The B_GIC index is a measure of geomagnetic activity designed indicate the level of GIC in the power grid. The horizontal dashed lines show the equivalent levels of the NOAA G-scales but extended beyond G5.

G1/UKG1	G2/UKG2	G3/UKG3	G4/UKG4	G5/UKG5
UKG6	UKG7	UKG8	UKG9	UKG10

Historical example of B_GIC

The plot below is an example of the B_GIC index during the Halloween storm in 2003

Modelled UK Geoelectric field

The plots below show the magnitude of the most recent modelled electric field in the UK.

Latest model

Northwards field (Click to enlarge).

Eastwards field(Click to enlarge).

Model calculation

This electric field is calculated every 15 minutes from a computer model. The magnetic field variations measured at the 3 UK magnetic observatories are combined with a model of the surface conductance across the UK (based on the geology - see map) to calculate the electric field on a 10km grid.