Driven magnetic reconnection in three dimensions: Energy conversion and field‐aligned current generation

We have analyzed the energy conversion processes occurring in three‐dimensional driven reconnection. In particular, we studied the energy conversion processes during localized reconnection in a taillike magnetic configuration. We find that three‐dimensional driven reconnection is a powerful energy converter which transforms magnetic energy into plasma bulk flow and thermal energy. Three‐dimensional driven reconnection is an even more powerful energy converter than two‐dimensional reconnection, because in the three‐dimensional case, plasmas were drawn into the reconnection region from the sides as well as from the top and bottom. Field‐aligned currents are generated by three‐dimensional driven reconnection. We have identified the physical mechanism responsible for these currents which flow from the tail toward the ionosphere on the dawnside of the reconnection region and from the ionosphere toward the tail on the duskside. The field‐aligned currents form as the neutral sheet current is diverted through the slow shocks which form on the outer edge of the reconnected field lines (outer edge of the plasma sheet).