Mysterious Solar Ripples Detected

by Dave Mosher, Staff Writer

Date: 30 August 2007 Time: 02:08 PM ET

For the first time, scientists have observed elusive oscillations in the Sun's corona, or atmosphere. The Alfvén waves, as the ripples are known, were tracked around the entire edge of the Sun traveling along the sun's magnetic field lines.
CREDIT: Steve Tomczyk and Scott McIntosh/NCAR

Mysterious waves that help transport the sun's energy out into space have been detected by scientists for the first time.

Researchers hope their discovery of the energetic ripples, known as Alfv?n waves, will shed light on other solar phenomena such as the sun's magnetic fields and its super-hot corona, or outermost atmosphere. A new video shows the ripples in action.

"Alfv?n waves can provide us with a window into processes that are fundamental to the workings of the sun and its impacts on Earth," said Steve Tomczyk, a space scientist with the National Center for Atmospheric Research (NCAR).

Like a wave traveling along a string, Alfv?n waves run along the sun's magnetic field lines and reach deep into space. While astrophysicists have identified the waves far away from the sun, they've never been detected close to our star?the ripples were too small and too fast to spot.

To observe the elusive waves, Tomczyk and his colleagues pointed the coronal multichannel polarimeter (CoMP) instrument, located at the National Solar Observatory's Sacramento Peak Observatory in New Mexico, at the sun's hot, hazy corona. Thanks to CoMP's imaging speed of one picture every 15 seconds, the scientists captured the waves traveling at about 9 million mph (14.5 million kilometers per hour).

"The waves are visible all the time and they occur all over the corona, which was initially surprising to us," said Scott McIntosh, a space scientist at the Southwest Research Institute in Boulder, Colo.

The waves might help explain how energy is transferred to the sun's corona, which is millions of degrees hotter than the solar surface.

Tomczyk and his colleagues' findings will be detailed in the Aug. 30 online edition of the journal Science.

SEE THE VIDEO: Solar Ripples
GALLERY: The Sun's Summer Storms
IMAGE: One Big Sun Spot