Top panel: vertical correlation length of the vertical velocity (solid line with triangles) and pressure scale height (dotted-dashed line) shown against the depth for the solar model. We indicate the different heights with the same color-coding as used in Fig. 17. Bottom panel: vertical correlation length scaled by the pressure scale height, which yields an average of 1.71 (dashed line) in the considered region for averaging the correlation length (vertical dotted lines with filled circles) for the solar simulation.