Geomagnetic Disturbance Data

​​​​​​NERC’s GMD data collection program supports ongoing research and analysis of GMD risk. GMD events are caused by the ejection of charged material from the sun and the interaction of this material with space around the earth (atmosphere and magnetosphere). The resulting disturbances in earth’s magnetic field have the potential to disrupt operations or cause damage to critical infrastructure, including power systems. Extremely strong GMD events, though rare, can induce strong quasi-dc currents in the electric power grid that could affect system voltages, relay and protection system performance, and the operation and health of some large power transformers.

Through the GMD data collection program, NERC is collection GIC and magnetometer data from reporting entities for designated strong GMD events (Kp = 7 and greater). As specified in FERC Order No. 830, NERC will make collected GIC and magnetometer data available to support ongoing research and analysis.

For more information about GMD, please contact

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expand Display Location : Section 1600 Data Request ‎(1)