As this solar wind storm buffets the magnetosphere, and portions of its energy are transferred to the magnetosphere, a geomagnetic storm results on Earth. When geomagnetic storms, natural hazards like hurricanes and tsunamis, are severe, they may disrupt local and global communications and abruptly increase drag on spacecraft and satellites, thus altering their orbits. The storms may also induce surges in electric power lines and cause equipment failures in a power grid. Such incidents may result in electric utility blackouts over a wide area. Some areas in the northeastern U.S. and Sweden also lost power.
Geomagnetic storms can last several hours or even days, waxing and waning several times a day.
The Earth's magnetosphere acts as a protective barrier preventing energetic solar particles and radiation in the hot solar wind from reaching the planet's surface. Most of these energetic particles are deflected around the Earth as they stream by, like a stone diverts the water in a fast flowing stream. The presence of these deflection streams, known as the Van Allen belt , was discovered in the late 1950s by the first earth satellites. Some electrons in the solar wind become trapped in the Earth's magnetic field and are then accelerated toward the magnetic polar regions and down into the upper atmosphere. Here, high in the atmosphere, the solar wind produces the incredible beauty of the aurora borealis around the northern magnetic pole and the aurora australis around the southern pole.