3D representation of the height (above the bottom boundary of the simulation) of the transition region, calculated as a temperature contour of 40 000 K at a specific snapshot in time of t = 1082 s. The strength of the v_z perturbation is shown on the bottom boundary plane and the shadow contour of the transition region height is projected against the y − z plane to highlight the surface waves formed at the transition region resulting from previous spicule launches.