Newly Identified Atmospheric Phenomena Named STEVE and “Picket Fence” Could be Entirely Separate from Aurora
Astronomers are still trying to understand the newly discovered atmospheric phenomena named STEVE, which appears in the Earth’s sky, especially around the poles. A new paper proposes that these unique atmospheric formations are not related to the well-known auroras, but are distinct and produced by electric fields parallel to the magnetic field lines.
The physicist Claire Gasque from the University of California Berkeley, leading a team of researchers, has put forth the radical idea that STEVE and the picket fence are not auroras, but something else entirely. It is proposed that the emissions are produced by the electric fields parallel to the magnetic field lines, at lower latitudes than the aurora.
“The STEVE spectrum is telling us there’s some very exotic physics going on. We just didn’t know what it was,” explains physicist Brian Harding of UC Berkeley. “Claire’s paper showed that parallel electric fields are capable of explaining this exotic spectrum.”
The auroras, often referred to as the Northern Lights, are caused by particles from the Sun colliding with Earth’s magnetosphere and creating an exciting display of colorful lights in the upper atmosphere. However, STEVE and the picket fence have their own unique display, with STEVE appearing as a mauve-and-white glow, often accompanied by striped green features.
Scientist Gasque explains that her team’s research has indicated that the picket fence emissions are being excited by an electric field locally, rather than originating from particles falling from a higher altitude. This is an entirely different mechanism than the one behind the auroras.
To test their hypothesis, the researchers propose launching a rocket into a STEVE or the picket fence. This would provide a direct way to study the phenomena and understand their unique physical processes. Despite the challenges of targeting these rare occurrences, the team is hopeful that the enhanced auroras, which are more common, could provide valuable insights into these atmospheric emissions.
“It’s fair to say that there’s going to be a lot of study in the future about how those electric fields got there, what waves they are or aren’t associated with, and what that means for the larger energy transfer between Earth’s atmosphere and space,” says Harding.
The research has been published in Geophysical Research Letters and could offer new insights into the complex interactions between Earth’s atmosphere and space. The discovery of STEVE and the picket fence has opened up a new area of study in space physics and atmospheric science.