Ratio of dust temperatures used in the radiative transfer to the power-law temperature profile from Eq. (A.1) (indicated by the green horizontal dotted line). The middle line of each curve is the average value of each shell, and the dark field is the standard deviation of each shell. The plot starts at 3 au, which is just below where dust forms at this snapshot (3.4 au). The vertical black dots indicate half the edge length (centre to edge distance) of the computation box.