The chromosphere is largely responsible for the deep ultraviolet radiation that hits Earth, producing our atmosphere's ozone layer.
The region might also contribute to climate change on Earth, researchers say (related: "Don't Blame Sun for Global Warming, Study Says" [September 13, 2006]).
Previously scientists have proposed either sound waves or the ever changing solar magnetic fields as potential causes of the chromosphere's unexpected heat.
The latest study shows "that the magnetic field and the sound wave go hand in hand to create a lot of the … mass and energy of the chromosphere," Bart De Pontieu, a researcher at the Lockheed Martin Solar and Astrophysics Lab in Palo Alto, California, said at the meeting.
The sun's interior vibrates with millions of sound waves, which are inaudible to humans but pack much more power than regular sound waves.
These waves are largely trapped by the photosphere.
Using spacecraft, ground-based telescopes, and computer simulations, scientists found that some of the trapped waves and their pent-up energy manage to leak out through magnetic "knots" in the photosphere.
The leaks send mass and energy streaming upward in thin fountains into the chromosphere.
"What we've discovered is exactly how these waves can leak out from the sun's interior through … naturally occurring magnetic portals," Southwest Research Institute's McIntosh said.
Scientists at the meeting said that the findings will help solar astronomers study other stars.
"We astronomers look at the sun in a very special way—it's the only star we can look at it in very high detail," said Andrea Dupree, a former AAS president.
"The lessons we're learning from the sun," Dupree said, "are ones we're going to take with us and look at all the other stars and think about how these other stars work."
Free Email News Updates
Sign up for our Inside National Geographic newsletter. Every two weeks we'll send you our top stories and pictures (see sample).
|
SOURCES AND RELATED WEB SITES
|
