The aurora borealis, or as it is known as the northern lights, has drawn the attention of astronomy enthusiasts for thousands of years, but this dancing glow in high latitudes has puzzled scientists for centuries because of the mystery of its causes.
According to the “RT” website, in a new study, a team of physicists led by the University of Iowa reported conclusive evidence that the brightest aurora is caused by strong electromagnetic waves during geomagnetic storms.
This phenomenon, known as Alfven waves, speeds electrons toward Earth, causing the particles to produce typical atmospheric light exposure.
The study, published online June 7 in Nature Communications, concludes a decades-long quest to prove the physical mechanisms of electron acceleration by these waves under conditions consistent with Earth’s auroral magnetosphere.
“Measurements revealed that this small group of electrons undergoes resonant acceleration by the electric field of a wave, similar to a surfer holding a wave and being continuously accelerated as the surfer moves,” said Greg Hawes, associate professor in the Iowa Department of Physics and Astronomy and co-author of the study. Along with the wave”.
Scientists knew that energetic particles emitted from the sun, such as electrons racing at 45 million miles per hour, are deposited along the Earth’s magnetic field lines in the upper atmosphere, where they collide with oxygen and nitrogen molecules, which leads to them being pushed into an excited state. These excited molecules relax by emitting light, producing the colorful shapes of the aurora borealis.
This theory was supported by spacecraft missions that repeatedly found that these waves travel toward Earth above the aurora borealis, presumably accelerating electrons along the way.
Although space measurements supported the theory, limitations inherent in spacecraft and rocket measurements prevented definitive testing.
The physicists found solid evidence in a series of experiments conducted in the Large Plasma Device (LPD) at the University of California, Los Angeles (UCLA) Plasma Science Core Facility, a collaborative research facility jointly supported by the US Department of Energy and the National Science Foundation.