Despite their typically dim presence during the nighttime in polar regions, auroras sometimes explode into arrays of brightness. Although this phenomenon was previously misunderstood, scientists from Kyoto University now understand the spectacle, which they've called an auroral breakup.
The team discovered that hot charged particles called plasmas congregate in the area just above the upper atmosphere of the polar region at a time when magnetic field lines reconnect in space. This process stimulates the rotation of the plasma, which initiates an electric current above the polar regions. In addition, another electric current overflows in proximity to the aurora in the upper atmosphere, which causes plasma rotation and a subsequent discharge of extra electricity. The end result is a "surge," the bright sparks of light that can be seen in the night sky during auroral breakups.
"This isn't like anything that us space physicists had in mind," Yusuke Ebihara, author of the study, said in a press release.
The results of the study come from a supercomputer simulation program that was created by Takashi Tanaka, a professor emeritus at Kyushu University.
"Previous theories tried to explain individual mechanisms like the reconnection of the magnetic field lines and the diversion of electrical currents, but there were contradictions when trying to explain the phenomena in its entirety," Ebihara said. "What we needed all along was to look at the bigger picture."
The paper builds on earlier work conducted by Ebihara and Tanaka that examined the nature of the emergence of these bursts, expanding the research to examine the process's expansion into a breakup.
The research offers the potential to be used to devise solutions to combat dangerous problems associated with auroral breakups that can disrupt satellite systems and power grids.
The findings were published in the Dec. 21 issue of the Journal of Geophysical Research.
