Sunspots seen in Spain as geomagnetic storm expected to reach Earth

The geomagnetic storm's intensity would probably be moderate or strong, levels one of two on a five-level scale, five being the most extreme, according to U.S. National Oceanic and Atmospheric Administration (NOAA).

Tourists gathered at Ronda's viewpoint to observe the sun.

Geomagnetic storms are disturbances of the Earth's magnetic field, lasting from several hours to several days, according to Spain's National Geographic Institute (IGN).

They are external in origin and are caused by an abrupt increase in particles emitted in solar flares that reach the magnetosphere, producing disturbances in the Earth's magnetic field.

Solar flares may affect positioning systems, navigation systems or communication satellites.