Geomagnetically induced Currents (GICs) are modelled in the UK power network using a combination of magnetic field data, a conductance model and a power network model. The 1-minute magnetic field measurements from the 3 UK observatories are interpolated to provide a grid of magnetic field variations across the whole UK. This is then combined with a model of the surface conductance, based on geology, to calculate the electric field. The power network model is constructed from information provided in the National Grid plc. Electricity Ten Year Statement. Using the modelled electric field the size of GICs flowing through each substation in that power network can then be calculated.

The average GIC is the mean of absolute current modelled at all substations for the selected region of the UK. Plots for Scotland, England and Wales and the UK are selected using the Select Data dialog.

Main page

To select the data set you want to see, and the range of dates and/or times you want to see it over, click the Select Data button and enter the relevant information in the dialog.

For data sets that can be viewed at different dates and/or times, use the Previous and Next buttons to step backward and forward by the date/time range currently shown on the page. Use the Most Recent button to see the most recently available data. The Next and Most Recent buttons will be disabled when the most recent data is displayed. The Previous button will be disabled when the page is showing the earliest data available for the current data set.

Select Data dialog

Select the data set you want to see from the drop-down menu.

Where applicable, select the observatory (observatories) or region(s) from the drop-down menu.

Where applicable, enter two dates/times separated by '-' in the input box to specify the date/time you want to see. Alternatively, select a date/time range using the date picker.