Relative magnetic helicity evolution calculation using the result of the GOEMHD3 simulation. The dash-dotted line represents the time when the fast reconnection started (t = 1035s). (a) Relative magnetic helicity in the simulation box (dashedline) and the accumulated relative helicity (solid line) sum of the helicity injection through the boundary and the dissipated in the volume helicity according to Eq. (6) in Yang et al. (2013). (b) Evolution of the normalized relative helicity, where the magnetic helicity is normalized by unsigned flux at the bottom boundary (solid line) and the six side boundaries (dashed line). (c) Injected magnetic helicity flux through the bottom boundary. (d) Injected magnetic helicity from the bottom boundary. (e) Magnetic helicity dissipation rate in the simulation box. (f) Magnetic helicity dissipation in the simulation box. (g) Magnetic helicity change rate escaped from the other five boundaries except the bottom boundary. (h) Magnetic helicity escaped from the upper five boundaries.