Observed the Kelvin-Helmholtz instability in the solar atmosphere

[ Instrument Network Instrument Development ] The international magazine "Astrophysics Express" recently published the latest observations of the one-meter new vacuum solar telescope of the Yunnan Observatory of the Chinese Academy of Sciences. The study was jointly led by Shen Yuanguang (co-first author) of Yunnan Astronomical Observatory and Yuan Ding, an associate professor of Harbin Institute of Technology. They found that the Kelvin-Helmholtz instability occurred between the hot and cold plasma streams. It has a heating effect on the solar atmosphere plasma.

The Kelvin-Helmholtz instability phenomenon occurs when there is an instability between fluid interfaces with different velocities. It can mix plasma components with different physical properties and kinetic energy of large-scale plasma motion structures. Transform into a small-scale structure.

Using high-resolution observations from the Yunnan Observatory's one-meter new vacuum solar telescope, the researchers successfully detected the Kelvin-Helmholtz instability that occurred in an outbreak on September 9, 2017 (as shown) . It is found that the Kelvin-Helmholtz instability occurs at the interface between the cold plasma stream and the thermal plasma stream, and it is also detected that the local plasma is rapidly heated to the corona plasma temperature during this phenomenon.

Because small-scale outbreaks generally occur in the solar atmosphere, researchers further speculate that Kelvin-Helmholtz instability should occur in solar plasma activities of different scales. This plays an important role in understanding the solar heating problems in solar physics.

The study was funded by the National Natural Science Foundation of China.