Fig. 6
Quantitative analysis of the temporal evolution of the the eruptive flux tube. a The 3D field lines structure at t = 0.4 where the color indicates the decay index value in a range from 0 to 1.5. The particle locating at the point (0.4686, 0.51420, 6.00 × 10−2)L* on a top of a black thick line is temporally traced. This field line is initially in non-equilibrium because this locates in an area satisfying n > 1.5, and eventually takes part in the large flux tube formed at late time. b 3D field lines at t = 7.2. The back thick line corresponds to the traced line. c Temporal evolution of the hight of the selected point of the traced line. d Temporal evolution of the velocity in red and the decay index in blue measured at each traced point. The dashed line marks the decay index value, n = 1.5. The red and blue masks mark regions, n ≥ 1.5 and n ≤ 1.5, respectively. e Temporal evolution of magnetic flux with more than one-turn in red and less than one-turn (but more than a half-turn) in blue
