Produced by the interaction between magnetic fields and plasma, sonic boom-like shock waves rip through the sun's atmosphere, yielding extreme heat. Photo by Queen's University Belfast
March 6 (UPI) -- Scientists have discovered a new mechanism responsible for the heating of the solar atmosphere and the propulsion of solar winds.
The new research, published this week in the journal Nature Physics, suggests magnetic waves excite the sun's atmosphere, heating up the upper layers and propelling solar winds into space.
A unique wave produced by magnetized plasma was first theorized by Swedish physicist and engineer Hannes Alfvén in 1942. So-called Alfvén waves have been linked with a variety of phenomenon, including nuclear reactors and cometary clouds.
Scientists also theorized Alfvén waves allow the sun's atmosphere to maintain extremely high temperatures, but until now, researchers couldn't prove it.
"For a long time scientists across the globe have predicted that Alfvén waves travel upwards from the solar surface to break in the higher layers, releasing enormous amounts of energy in the form of heat," David Jess, physicist at Queen's University Belfast, said in a news release. "Over the last decade scientists have been able to prove that the waves exist but until now there was no direct evidence that they had the capability to convert their movement into heat."
Jess and his colleagues were able to -- for the first time -- detect the heat generated by Alfvén waves inside a sunspot.
"Our research opens up a new window to understanding how this phenomenon could potentially work in other areas such as energy reactors and medical devices," Jess said.
Scientists analyzed the magnetic fields inside sunspots using observations collected by the Dunn Solar Telescope in New Mexico and NASA's Solar Dynamics Observatory. The magnetic patterns observed by scientists recall the magnetic field produced by modern MRI machines -- only on more massive scales.
"By breaking the sun's light up into its constituent colors, our international team of researchers were able to examine the behavior of certain elements from the periodic table within the sun's atmosphere, including calcium and iron," said Queen's researcher Samuel Gran.
Researchers were able to remove the interference of theses elements from the images, revealing the conversion of Alfvén waves and their energy into shock waves. The intense flashes of light recalled the sonic boom produced by an aircraft breaking the sound barrier. As the shock wave ripples through the plasma in the solar atmosphere, it's release extreme heat.
"Using supercomputers, we were able to analyze the data and show for the first time in history that the Alfvén waves were capable of increasing plasma temperatures violently above their calm background," said Gran.