Comparison between the average drift speed of the different dust size particles. These values are calculated at the end of the simulation at R = 1.8 with the analytical drift speed (black solid line), the migration speed of a 5 M_⊕ (dotted line), and a 10 M_⊕ (dashed line) mass planet. The error bars reflect the impact of radial diffusion for the various stopping times. The smaller particle sizes in the VSI simulation are migrating outwards rather then inwards due to the inverse meridional circulation (Stoll et al. 2017a).