A closeup of the area highlighted by the white box at lower left of the right-hand panel in Movie 1. The closeup region spans about 27,000 by 27,000 miles (43,500 by 43,500 kilometers). In this repeating, 2-second loop, the white dashed lines superimposed on the data give a sense of scale for the motion of Alfvén waves as they transport a significant amount of energy through the Sun's corona. The waves cause high-speed jets of hot material associated with spicules to sway, or wiggle side to side. These new satellite observations have revealed that the wiggling waves are over a hundred times stronger than previously measured, with amplitudes on the order of 12 miles per second (20 km/sec)—enough to heat the Sun's outer atmosphere to over a million degrees and drive the solar wind.
This research sheds light on why the Sun's outer atmosphere, or corona, is more than 20 times hotter than its surface, and helps bring scientists a step closer to understanding the solar cycle and the Sun's impacts on Earth.
Visualization by Scott McIntosh, NCAR scientist, of data from the Atmospheric Imaging Assembly, a package of instruments aboard NASA's Solar Dynamics Observatory.
The study, by scientists at NCAR, Lockheed Martin Solar and Astrophysics Lab, Norway's University of Oslo, and Belgium's Catholic University of Leuven, is published in the journal Nature, July 28, 2011.