March 3 (UPI) -- The precise origins of a unique type of hazardous solar particle have been identified for the first time by a team of scientists in Britain and United States.
High-energy solar particles are regularly propelled into space by electromagnetic storms on the sun's surface. Sometimes, these particles collide with Earth.
They can disrupt satellite communications, and if they penetrate Earth's electromagnetic shield and atmosphere, they can damage power grids.
For the new study, researchers at University College London and George Mason University, in Virginia, compared the compositional signatures of Earthbound high-energy particles streaming through space with those recorded within the sun's atmosphere.
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Scientists found a match between the solar storm particles and particles streaming through the lower layers of the sun's corona, near the middle region of the solar atmosphere, called the chromosphere.
Researchers shared their breakthrough discovery in a new paper, published Wednesday in the journal Science Advances.
"In our study we have observed for the first time exactly where solar energetic particles come from on the sun," study co-author Stephanie Yardley said in a news release.
"Our evidence supports theories that these highly charged particles originate from plasma that has been held down low in the sun's atmosphere by strong magnetic fields. These energetic particles, once released, are then accelerated by eruptions that travel at a speed of a few thousand kilometers a second," said Yardley, an expert on space weather and a research fellow at UCL.
Because high-energy particles are accelerated to such high-speeds with the sun's corona, their path from sun to Earth can take just a few minutes -- though, the trip usually lasts several hours.
In other words, these dangerous particles usually arrive without warning.
"Currently, we can only provide forecasts of these events as they are taking place, as it is highly challenging to predict these events before they occur," Yardley said. "By understanding the sun's processes better we can improve forecasts so that, when a major solar storm hits, we have time to act to reduce risks."
The Earthbound particle streams analyzed for the latest study were observed using NASA's Wind satellite, which is positioned halfway between the sun and Earth. For 24-hours at a time, the satellites recorded the stream's spectral signatures, revealing the chemical composition of the stream's high-energy particles.
Scientists compared these signature to those recorded by the JAXA-led Hinode spacecraft, which is tasked with studying the sun's magnetic fields.
The chemical fingerprints recorded by the Wind satellite, characterized by high concentrations of silicon compared to sulphur, matched those observed by Hinode at the base of hot coronal loops, which are the arches of plasma that leap from the sun's outer atmosphere.
Hinode data showed the magnetic fields near the base of hot coronal loops are especially high, which suggests strong magnetic forces help confine concentrations of high-energy particles prior to their release into space.
According to the study's authors, the findings offer further proof that the high-energy particles emanating from the sun's chromosphere are distinct from the slower-moving solar winds traditionally associated with solar storms.
With more and more satellites and telescopes being aimed at the sun, scientists expect to gain new insights into the complexities of the sun's electromagnetic phenomena in the years ahead.
"Our observations provide a tantalizing glimpse into where the material that produces solar energetic particles comes from in a few events from the last solar cycle," said lead author David Brooks, astrophysicist at George Mason. "We are now starting a new solar cycle, and once it gets going we will use the same techniques to see if our results are generally true, or if these events are somehow unusual."
"We are lucky in that our understanding of the mechanisms behind solar storms and solar energetic particles is likely to advance quickly over coming years thanks to data that will be gained from two spacecraft -- ESA's Solar Orbiter and the NASA Parker Solar Probe -- that are heading closer to the Sun than any spacecraft has been before," Brooks said.
