Kinematics evolution of the SES case and FES case. Panels (a) and (b) show several field lines originating from the center of the positive footpoint at (0, 28, 0) Mm in SES and FES. Panels (c) and (d) present the evolution of the flux-rope height (green lines with dots) and rotation angle (yellow lines with crosses) by measuring the height and tangential angle at the apex of the field lines in SES and FES.