Definition
A geomagnetic storm is a temporary disturbance of Earth's magnetic field caused by the solar wind or by coronal mass ejections (CMEs). When the solar wind is fast and its magnetic field couples with Earth's magnetosphere (especially when the interplanetary field is southward), currents and particle precipitation increase. This is measured globally by the Kp index (0–9). Storms can cause aurora at lower latitudes, and in strong cases affect power grids, satellites, and radio/GPS. Cosmic Radar shows the daily Kp and space weather events in the report.
Sources and further reading
- NOAA – Geomagnetic storms – Official definition and impacts
- NOAA Kp index – How Kp is derived