Evolution of the kinetic energy of the system. Top: normalised perpendicular component of the kinetic energy, kE_⊥/kE_⊥, 0. The dashed red and blue lines represent the energy within the corona and the lower atmosphere, respectively. The solid lines are envelopes. Bottom: normalised parallel component of the kinetic energy, kE_∥/kE_⊥, 0. The dashed red and blue lines represent the energy within the corona and the lower atmosphere, respectively. The solid lines are envelopes.