资源环境科技发展态势分析平台

Flux transfer events are transient magnetized plasma structures that are self‐balancing, rope‐like phenomena that can appear at the Earth’s magnetopause when the interplanetary magnetic field is southward. The formation of this type of flux rope has been unclear. Using measurements of particles and magnetic fields on the MMS spacecraft, we find that rope‐like structures containing magnetospheric energetic electrons have exactly the same occurrence rate as those without magnetospheric electrons, independent of solar wind properties and location of observation. This equality is consistent with a pair of flux bundles being generated at the same time, but displaced from each other as an outcome of their collision and resultant entanglement and reconnection. This entanglement reconnection produces one flux rope with two ends connected to the magnetosphere, and the other connected on both ends to the shocked solar wind. Away from the subsolar entanglement zone, reconnection transports magnetic flux from the ‘closed’ magnetosphere to the ‘open’ tail lobes, as predicted by Dungey (1961).