Time profiles of the magnetic flux, helicity, and energy for the Type-I AR 11620. Panel (a): time evolution of the unsigned magnetic flux Φ (black) and accumulated energy ΔE (blue). Panel (b): time profile of the helicity flux, d(H)/dt (black). The red and green curves represent the shear and emergence terms, respectively. Panel (c): time profiles of accumulated helicity ΔH. The red and green curves indicate the helicity of the emergence term and shear term, respectively.