geomagnetic storm

A geomagnetic storm is a short-term disruption of the magnetic field surrounding Earth, i.e., a temporary change from its usual state, typically returning to normal in a few days. Such storms are invariably from influence of the Sun, and can be thought of as a solar storm that specifically affects the Earth's magnetic field, e.g., due to solar activity such as a coronal mass ejection, etc. Such storms can affect radio communication, power, satellites, etc., and often include auroras.