#(twisting)

"Researchers from the U.S. National Science Foundation National Solar Observatory (NSF NSO), the Max Planck Institute for Solar System Research (MPS) in Germany, and the High Altitude Observatory (HAO) in the U.S. have made a discovery in solar physics. New images of the sun's surface taken with the world's largest solar telescope, the NSF Daniel K. Inouye Solar Telescope, built and operated by the NSO in Hawaii, along with sophisticated computer simulations, reveal tiny plasma vortices that had never before been visible."

"The vortices occur at the edges of so-called granules, which densely cover the sun's visible surface. They measure between 500 and 2,000 kilometers (310 to 1,240 miles) in diameter. Taken together, they form the sun's granulation: a pattern reminiscent of bubbles in a boiling liquid.

In fact, the granulation stems from plasma flows that rise from the sun's hot interior, cool down and sink back into the depths. In the new study published in Nature, researchers succeeded for the first time in visualizing fringed structures at the edges of the granules. Time and again, these structures display swirling motions resembling breaking ocean waves. Some of these "fringes" are little more than 20 kilometers (12 miles) wide.

The researchers interpret the swirling plasma flows as signs of Kelvin–Helmholtz instabilities. This is a well-known effect in fluid dynamics. It occurs when two fluids flow past each other at different speeds. This generates shear forces at the interface, causing minute disturbances to grow into wave- or vortex-like flows. The effect manifests itself in a wide variety of contexts and on different scales—for example, on the surfaces of lakes or in ocean waves, in cloud formation, in the atmospheres of the giant gas planets Jupiter and Saturn, and in the interaction of the solar wind with planetary magnetospheres.

Apparently, adjacent plasma layers at the edges of solar granules also flow at different speeds, creating the necessary conditions for Kelvin–Helmholtz instabilities."