Temporal Evolution of Flux Tube Entanglement at the Magnetopause as
Observed by the MMS Satellites
Flux transfer events (FTEs), as flux ropes (FRs), are considered key
agents for solar wind energy to enter the terrestrial magnetosphere.
Recent observations identify entangled flux tubes that collide and pull
against each other. Reconnection occurs to disentangle and produce a new
pair of flux ropes with different connectivity. In this paper, we
examine how such an entanglement process evolve in time by comparing 17
entanglements observed by the Magnetospheric Multiscale (MMS) mission.
The By-dominated interplanetary magnetic field (IMF) distribution of the
entangled tubes agrees with previous findings. We have identified three
evolutionary stages characterized by the magnetic field and pressure
enhancement. Our study confirms the flux rope nature of these events and
explains how a disparate pair of ropes is formed from two entangled flux
tubes, each initially connected to a different hemisphere of the