Dartmouth Events

Abstract: Magnetic reconnection is a fundamental plasma process, which converts magnetic energy into particle energy via topological changes in magnetic fields. It occurs ubiquitously in space and throughout the universe, and it is believed to be responsible for various explosive phenomena. Magnetic reconnection in Earth’s magnetotail plays a crucial role in the most important explosive phenomena in Earth’s magnetosphere, storms and substorms, which involve a sudden transition from a quiescent state to a rapid energy release. How this transition begins, i.e., the onset of magnetotail reconnection, however, has been a long-standing conundrum. I will talk about the theoretical and simulation efforts in the past 50 years devoted to explain the onset of magnetotail reconnection, which have led to several distinct, evolutionary mechanisms. I will also talk about spacecraft observations as experimental evidences for these mechanisms.