Height evolution (top panel), average kinetic energy density (second panel), average thermal energy density (third panel), average magnetic free energy density (fourth panel), and average seeped energy density (last panel) for the six different σ-cases. The vertical black line marks the time at which footpoint motion is off (t = t₁). Energy densities are expressed in erg cm⁻³ and are averaged over the entire simulation domain |x|< 30 Mm and y <  300 Mm.