Blue Sky Science: What is a solar flare?
Q What is a solar flare?
— William Allen, Robbinsdale, Minn.
A Alex Lazarian, professor in the departments of astronomy and physics at the University of Wisconsin-Madison:
A solar flare is a release of magnetic energy from the sun. The energy is stored as a magnetic field around the sun and then is released with energetic particles and waves coming from the solar surface.
Huge amounts of energy are released during solar flares, which can be spectacular events.
These solar flare events are related to a process called magnetic reconnection, or the annihilation of the magnetic field.
There are magnetic fields that are of opposite polarity, with some magnetic fields going one direction and other magnetic fields going the opposite way.
When these opposing magnetic fields come into contact, reconnection occurs and may be explosive, as in the case of solar flares.
Scientists still debate the cause of the explosions. In general, the sun is undergoing an 11-year cycle called the solar cycle that affects the sun’s radiation, number of solar flares and number of sun spots.
This cycle reflects fluctuations in solar activity and changes the polarity of the sun every 11 years.
Solar flares can affect life on Earth in a number of ways. They are responsible for beautiful natural phenomena like the auroras.
Scientists today are most concerned about effects on sensitive radioelectronic equipment up in orbit. Solar flares can damage this equipment in orbit, affect communications systems on airplanes, or even short-circuit electronic systems on the ground.