Energy Source for the Aurora

Rather large amounts of power are required to produce the aurora seen in the two polar regions. During a moderate to large auroral display lasting one to three hours the energy dissipated by the auroral processes is about the same as released in a Richter magnitude 6 earthquake, in a cyclone, or in a small nuclear bomb.

It is almost certain that the energy required to power the aurora comes from the sun. From the sun there is a continual outflow of matter in the form of electrons and nuclei of atoms, mostly hydrogen nuclei (protons). This flow, called the solar wind, streams at speeds near 400 km/sec (900,000 mph) and therefore takes severel days to reach the earth, whereas light takes only eight minutes.

Near the earth, the energy of motion within the solar wind is converted to electromagnetic energy--by the same process that an electrical generator converts energy of motion to electrical energy. That energy is again converted to energy of motion of those electrons and protons which stream down into the atmosphere to collide with the air to cause the aurora we see.

The details of energy conversion and energy transfer processes are very complex and not yet entirely understood. If we can understand the details, the knowledge should give valuable insight into cosmological processes, since we suspect that the processes in the aurora are those which also occur in stellar bodies and perhaps elsewhere in the Universe.