Bi-directional plasma jets produced by magnetic reconnection on the Sun

Abstract

Magnetic reconnection, the process by which magnetic lines of force break and rejoin into a lower-energy configuration, is considered to be the fundamental process by which magnetic energy is converted into plasma kinetic energy¹. The Sun has a large reservoir of magnetic energy, and the energy released by magnetic reconnection has been invoked to explain both large-scale events, such as solar flares^2,3 and coronal mass ejections⁴, and small-scale phenomena, such as the coronal and chromospheric microflares that probably heat and accelerate the solar wind^5,6. But the observational evidence for reconnection is largely indirect, resting on observations of variations in solar X-ray morphology and sudden changes in the magnetic topology^7,8, and on the apparent association between some small-scale dynamic events and magnetic bipoles^9,10. Here we report ultraviolet observations of explosive events in the solar chromosophere that reveal the presence of bi-directional plasma jets ejected from small sites above the solar surface. The structure of these jets evolves in the manner predicted by theoretical models of magnetic reconnection^11,12, thereby lending strong support to the view that reconnection is the fundamental process for accelerating plasma on the Sun.