The sky phenomenon, known as STEVE, is probably due to a combination of heating of charged particles in the atmosphere and energy electrons like those that power the glow, according to new research. In a new study, scientists have discovered the region of the source of STEVE in space and identified two mechanisms that cause it.
Last year, unclear atmospheric lights became an Internet sensation. Typical shades, north and south lights are commonly seen as rotating green ribbons spreading across the sky. But STEVE is a thin strip of pink-red or purple-colored light that extends from east to west farther south to where the radiance usually appears. Even stranger is that STIVs are sometimes joined by green vertical columns of light called a stack of stakes.
Aurors are produced by luminous atoms of oxygen and nitrogen in the upper atmosphere of the Earth, excited by charged particles emanating from the magnetic environment near the Earth, called the magnetosphere. The scientists did not know if STEVE was something like a glow, but a 2018 study found that its glamor was not due to charged particles falling down into the upper atmosphere of the Earth.
The authors of the 2018 study called STEVE some sort of "heavenly glow" that was different from the aurora but were not sure exactly what caused it. The complication of the matter is the fact that STEVE can occur during magnetic storms caused by solar energy around the Earth that feed the brightest lights of the glow.
Authors of a new study, published in the AGU journal Geophysical studies analyzes satellite data and earth images of STEVE events and concludes that the red arc and the green fence are two different phenomena arising from different processes. Stack fences are caused by a mechanism similar to the typical shades, but the STEVE paths are colored by heating charged particles higher in the atmosphere, similar to what makes light bulbs illuminate.
"Aurora is determined by the precipitation of particles, electrons, and protons that actually fall into our atmosphere, while the atmospheric glow of STEVE comes from non-precipitation warming," said Bea Gallardo-Lacourt, a cosmic physicist at Calgary University and co-author of a new study . "The expressing electrons that cause the green fence are thus aurora, although this happens outside of the aura, so it's really unique."
STEVE's images are beautiful in themselves, but they also provide a visible way to study the invisible, complex streams of charged particles in the Earth's magnetosphere, according to the authors of the study. The new results help scientists better understand how particle fluxes develop in the ionosphere, which is an important goal, as such disturbances can interfere with radio communications and affect GPS signals.
Where does STEVE come from?
In the new study, the researchers wanted to understand what STEVE's powers are and whether it appears simultaneously in the Northern and Southern hemispheres. They analyzed data from several satellites passing through the head during the STEVE events in April 2008 and May 2016 to measure the electric and magnetic fields in the Earth's magnetosphere at that time.
The researchers then collected the satellite data with STEVE photographs taken by amateur aurally photographers to understand what caused the unusual glow. They discovered that during STEVE, a "river" of charged particles in the ionosphere of the Earth collides, creating friction that heats the particles and causes them to emit light-blue light. Incandescent lamps work in the same way that electricity heats a tungsten spiral while it is hot enough to shine.
Interestingly, the study found that stack fence was powered by vigorous electrons moving from space thousands of kilometers above Earth. Though similar to the process that creates typical luminosity, these electrons affect the atmosphere far south of the usual aurora latitudes. Satellite data shows that high frequency waves moving from Earth's magnetosphere to its ionosphere can activate electrons and push them out of the magnetosphere to create the band fence.
Researchers also found that the stack fence is found in the two hemispheres at the same time, supporting the conclusion that its source is high enough above Earth to supply energy to the two hemispheres at the same time.
Public participation is critical to STEVE's research by providing terrestrial imagery and accurate weather and location data, according to Toshi Nishimura, a Boston University space physicist and lead author of the new study.
"As the cameras become more sensitive and the growing aura around the aurora spreads through social media, civilian scientists can act as a" mobile sensor network "and we are grateful to them for providing us with analytical data," Nishimura said.