Time evolution of the surface density Σ_d (top panels), radius a (middle panels), and radial mass flux Ṁ_r (bottom panels) of dust particles as a function of orbital radius r for models with α = 10^-3 and with r_out = 100 AU (left panels) and 300 AU (right panels). The black dotted lines show the initial condition, while the blue dashed, solid, dash-dotted, and dotted lines are the snapshots at times t = 0.1, 0.5, 1, and 5 Myr, respectively. The jumps in Σ_d and a at r ≈ 1 AU, t = 0.1 Myr are caused by rapid coagulation of particles initially located at these orbits (see text).