Geomagnetic storm
Also called: Solar storm · Topic: Origin and Evolution of the Earth and the Solar System · NCERT: Beyond NCERT
Meaning
A geomagnetic storm is a major disturbance of the Earth's magnetosphere (the region around the Earth controlled by its magnetic field). It is caused by a strong burst of solar wind or a coronal mass ejection (CME), a huge cloud of charged gas thrown out by the Sun. During a storm, auroras (glowing lights in the sky) can be seen much closer to the equator than usual. Strong storms can disrupt satellites, GPS, radio and power grids. NOAA rates them from G1 (minor) to G5 (extreme).
Example
In May 2024, a G5 storm produced auroras over Ladakh. They were photographed from the Indian Astronomical Observatory at Hanle. The largest storm on record is the Carrington Event of 1859.
Don't confuse with
- Solar storm: a loose term for the outburst on the Sun itself, such as a CME. A geomagnetic storm is what happens to the Earth's magnetic field when that outburst arrives.