قالب وردپرس درنا توس
Home https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Science https://server7.kproxy.com/servlet/redirect.srv/sruj/smyrwpoii/p2/ Scientists discover what powers celestial phenomenon STEVE

Scientists discover what powers celestial phenomenon STEVE



 Scientists discover what powers celestial phenomenon STEVE
Amateur astronomer's photograph used in the new research. The photograph was taken on May 8, 2016, in Keller, Wash. The major structures are two bands of upper atmospheric emissions 160 kilometers (100 miles) above the ground, possibly arc and green picket fence. The black objects at the bottom are trees. The background star constellations include Gemini and Ursa Major. Credit: Rocky Raybell.
            

The celestial phenomenon known as STEVE is probably caused by a combination of heating of charged particles in the atmosphere and energetic electrons like that of power, according to new research. In a new study, scientists found STEVE's source region in space and identified two mechanisms that cause it.
                                               


Last year, the obscure atmospheric lights became an internet sensation. Typical auroras, the northern and southern lights, are usually seen as swirling green ribbons spreading across the sky. But it is a thin ribbon of pinkish-red or mauve-colored light stretching from east to west, and usually south of where auras usually appear. Even more strange, STEVE is sometimes joined by green vertical columns of light nicknamed the "picket fence."

Auroras are produced by oxygen and nitrogen atoms in Earth's upper atmosphere, excited by charged particles streaming in from the near-Earth magnetic environment called the magnetosphere. Scientists did not know if they were a child of a school, but a 2018 study found its glow is not due to particles particles down to Earth's upper atmosphere.

The authors of the 2018 study dubbed STEVE a kind of "sky- glow "that is distinct from the aurora, but were unsure exactly what was causing it. Complementing the matter was the fact that STEVE can appear during solar-induced magnetic storms around Earth that power the brightest auroral lights.

Authors of a new study published in AGU's journal Geophysical Research Letters ground images of STEVE events and conclude that the reddish arc and green picket are two distinct phenomena arising from different processes. The picket fence is a mechanism similar to typical auroras, but STEVE's mauve is caused by heating of charged particles higher in the atmosphere, similar to what causes light bulbs to glow.

 Scientists discover what powers celestial phenomenon STEVE [19659009] Alberta Aurora Chasers capture STEVE, the new-to-science upper atmospheric phenomenon, on the evening of April 10, 2018 in Prince George, British Columbia, Canada. Fellow Aurora Chaser Robert Downie kneels in the foreground while photographer Ryan Sault captures the narrow ribbon or white-purple hues overhead. Credit: Ryan Sault.
            </figcaption></figure>
</div>
</div>
<p> "Aurora is defined by particle precipitation, electrons and protons actually falling into our atmosphere, while the STEVE atmospheric glow comes from heating without particle precipitation," said Bea Gallardo-Lacourt, a space physicist at the University of Calgary and Co. author of the new study. "The precipitating electrons that cause the green picket are thus aurora, though this occurs outside the auroral zone, so it's indeed unique." [Images] STEVE are beautiful in themselves, but they also provide a visible way to study the invisible. , complex charged particle flows in Earth's magnetosphere, according to the study's authors. The new results help scientists better understand how particle flows develop in the ionosphere, which is important goal because such disturbances can interfere with radio communications and affect GPS signals. </p>
<p> <b> Where does STEVE come from? </b> </p>
<p> In the new study, researchers wanted to find out what powers STEVE and if it occurs in both the Northern and Southern Hemispheres at the same time. They analyzed data from several satellites passing overhead during STEVE events in April 2008 and May 2016 to measure the electric and magnetic fields in Earth's magnetosphere at the time. </p><div><script async src=

The researchers then coupled the satellite data with photos of STEVE taken by amateur auroral photographers to figure out what causes the unusual glow. They found that during STEVE, a flowing "river" of charged particles in Earth's ionosphere collide, creating friction that heats the particles and causes them to emit mauve light. Incandescent light bulbs work in much the same way, where electricity heats a filament of tungsten until it's hot enough to glow.

 Scientists discover the powers of celestial phenomenon STEVE
region which falls into the auroral zone (green), the plasmasphere (blue) and the boundary between them called the plasmapause (red). The THEMIS and SWARM satellites (left and top) observed waves (red squiggles) that power the STEVE atmospheric glow and picket fence (input), while the DMSP satellite (bottom) detected electron precipitation and a conjugate glowing arc in the southern hemisphere. Credit: Emmanuel Masongsong, UCLA, and Yukitoshi Nishimura, BU / UCLA.
            

Interestingly, the study found the picket fence is powered by energetic electrons streaming from space thousands or kilometers above Earth. Similar to the process that creates typical auroras, these electrons impact the atmosphere of the usual auroral latitudes. The satellite data showed high frequency waves moving from Earth's magnetosphere to its ionosphere can energize electrons and knock them out of the magnetosphere to create the striped picket fence display.

The researchers also found the picket fence occurs in both hemispheres at the same time, supporting the conclusion that its source is high enough above Earth to feed energy to both hemispheres simultaneously.

Public involvement has been crucial for STEVE research by providing ground-based images and precise time and location data, according to Toshi Nishimura, a space physicist at Boston University and lead author of the new study.

"As commercial cameras become more sensitive and increased excitement about the aurora spreads via social media, citizen scientists can act as a" mobile sensor network, and we are grateful to them for giving us data to analyze, "Nishimura said.
                                                                                                                        


New child of aurora is not an aurora at all


More information:
Y. Nishimura et al., Magnetospheric signatures of STEVE: Implication for the magnetospheric energy source and inter-hemispheric conjugation, Geophysical Research Letters (2019). DOI: 10.1029 / 2019GL082460

Provided by
American Geophysical Union

Citation :
                                                 Scientists discover what powers celestial phenomenon STEVE (2019, April 25)
                                                 retrieved April 25, 2019
                                                 from https://phys.org/news/2019-04-scientists-powers-celestial-phenomenon-steve.html
                                            

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
                                            part may be reproduced without the written permission. The content is provided for information purposes only.
                                            


Source link