Galactic vertical force. Top panel: K_z forces versus Galactic radii at z = 0.5 (black thin solid line), 1.1 (red dashed), and 2 kpc (cyan dotted) from the Galactic plane (red). Green dots are the K_z force at 1.1 kpc from Wang et al. (2022). The blue thick line is the total surface mass density of stellar discs. The magenta line is the total (stellar+ISM+dark matter) density below |z| = 500 pc that can be compared to the K_z force at 500 pc. Bottom panel: K_z forces versus z at three Galactic radii R = 6 (green solid line), 8.1 (blue dashed), and 10.2 kpc (black dotted line).