Magnetic Waves As the Source of Extra Energy in the Sun’s Corona

Magnetic waves known as Alfvén waves from the cool lower solar atmosphere had long been proposed as the source, but there had been scant evidence that such waves were powerful and abundant enough to power the corona.Now an international team of scientists has discovered these waves may be far more profuse and up to more than 100 times stronger than before seen, potentially delivering about 10,000 times more energy overall to the corona than ever detected. With the help NASA’s Solar Dynamics Observatory satellite to image structures and motions on the sun with about 540-mile (870-kilometer) resolution every 12 seconds, the scientists detected these magnetic waves throughout the corona.

The scientists’ calculations show that the Alfvén waves are capable of driving the solar wind and heating much of the corona. According to scientists the next question is to find out what fraction of that energy is converted into heat. It could be all of it, or it could be 20 percent of it.