A spacecraft diving into the sun’s atmosphere has discovered the probable cause of strong bursts of plasma in fast solar winds.
The solar wind, which is the continuous flow of charged particles from the sun, has two distinct speeds known as “slow” and “fast.” It was previously unclear what was propelling the fast solar wind. Most of the plasma in the solar wind is made up of protons, electrons, and atomic nuclei that travel at hundreds of kilometers per second. However, plasma from the region above the coronal holes can travel more than ten times faster.
The fast plasma streams were linked to events called switchbacks, in which parts of the magnetic fields near the sun reverse direction. Switchbacks can occur when magnetic field loops near the sun’s surface connect to long field lines extending away from the sun. The reconnection causes a sharp switchback kink that propels the plasma into space as the kink straightens out.
The researchers suggest that higher energy streams are the result of newly reconnected field lines with sharply kinked switchbacks, while lower energy streams come from field lines with older kinks that have become more smoothed out.
2023-06-07 10:00:00
Post from www.sciencenews.org
