Mystery of the "pearl necklace" of the atmosphere has been revealed

New computer models and satellite observations have helped scientists identify the processes behind the formation of special-type auroras framing the night sky like a radiant pearl necklace.

"We now know for sure that the formation of beads is part of the pre-magnetospheric subbure process," said Vasilis Angelopoulos, lead researcher on the THEMIS mission at the University of California, Los Angeles.

Scientists have found that such auroras are caused by turbulence in the Earth-ambient plasma - the fourth state of matter - consisting of gaseous and charged particles with high conductivity.

"Turbulence in space causes streams that illuminate the sky in the form of a chain of individual pearls," said Evgeny Panov, lead author of one of the new articles and a researcher at THEMIS from the Institute of Space Studies of the Austrian Academy of Sciences.

"This cosmic turbulence is initially caused by lighter and movable electrons moving with a particle mass 2,000 times heavier, and could theoretically develop to full-scale auroral subbures."

Auroras occur when charged particles from the Sun enter the Earth's magnetosphere, where collisions cause the glow of atoms and molecules of hydrogen, oxygen and nitrogen. By modeling the near-Earth environment, THEMIS scientists were able to show details of how the "beads" of the aurora are formed.

When the plasma streams erupted by the Sun pass by the Earth, their interaction with the magnetic field of our planet creates floating plasma bubbles. Like a lava lamp, the imbalance of buoyancy between bubbles and heavier plasma in the magnetosphere creates plasma strokes that stretch down to the Earth and create a clear structure in the form of beads in the aurora.

The study is published in the journal Geophysical Research Letters and the Journal of Geophysical Research: Space Physics.