Researchers have found answers to why sometimes the auroras explode in brightness – a phenomenon called auroral breakup.

According to scientists at the Kyoto-Kyushu, hot charged particles, or plasmas, gather in near-Earth space when magnetic field lines reconnect in space. This makes the plasma rotate, creating a sudden electrical current above the polar regions. Furthermore, an electric current overflows near the bright aurora in the upper atmosphere, making the plasma rotate and discharge the extra electricity. This gives rise to the “surge”, the very bright sparks of light that characterize substorms.

The study that led to the findings is published in the Journal of Geophysical Research and it overthrows existing theories about the mechanism behind this phenomenon. While researchers have provided explanations as to why auroras occur, they haven’t been able to find explanation to how very bright sparks emerge in the sky during auroras.

“This isn’t like anything that us space physicists had in mind,” said study author Yusuke Ebihara of Kyoto University. Ebihara based the study on a supercomputer simulation program developed by Takashi Tanaka, professor emeritus at Kyushu University.

Some scientists have tried explaining the auroral breakup through theory that the acceleration of plasma from the reconnection of magnetic field lines caused the substorms, while others have argued that the electrical current running near the Earth diverts a part of the electrical current into the ionosphere for some unknown reason, triggering the bright bursts of light.

Tanaka’s supercomputer simulation program, on the other hand, offers a logical explanation from start to finish.

“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,” said Ebihara. “What we needed all along was to look at the bigger picture.”

The current paper builds on earlier work by Ebihara and Tanaka about how the bursts emerge. This explores the succeeding processes, namely how the process expands into a large scale breakup.

The research also has the potential to alleviate hazardous problems associated with auroral breakups that can seriously disrupt satellites and power grids.

http://www.dispatchtribunal.com/auroral-mystery-surrounding-sudden-bursts-solved/8781/