Experimental findings about plasma wave reflection could answer questions about high temperatures.
Experimental findings about plasma wave reflection could answer questions about high temperatures.
There is a profound mystery in our sun. While the sun’s surface temperature measures around 10,000 degrees Fahrenheit, its outer atmosphere, known as the solar corona, measures more like 2 million degrees Fahrenheit, about 200 times hotter. This increase in temperature away from the sun is perplexing and has been an unsolved mystery since 1939, when the high temperature of the corona was first identified. In the ensuing decades, scientists have tried to determine the mechanism that could cause this unexpected heating, but so far, they have not succeeded.
Now, a team led by Sayak Bose(Link opens in new window), a researcher at the U.S. Department of Energy(Link is external)’s (DOE) Princeton Plasma Physics Laboratory (PPPL), has made a significant advancement in understanding the underlying heating mechanism. Their recent findings show that reflected plasma(Link is external) waves could drive the heating of coronal holes, which are low-density regions of the solar corona with open magnetic field lines extending into interplanetary space. These findings represent major progress toward solving one of the most mysterious quandaries about our closest star.
“Scientists knew that coronal holes have high temperatures, but the underlying mechanism responsible for the heating is not well understood,” said Bose, the lead author of the paper(Link is external) reporting the results in The Astrophysical Journal. “Our findings reveal that plasma wave reflection can do the job. This is the first laboratory experiment demonstrating that Alfvén waves reflect under conditions relevant to coronal holes.”
Read more at DOE/Princeton Plasma Physics Laboratory
Photo Credit: AstroGraphix_Visuals via Pixabay
