Schematic edge-on views of the protoplanetary disc models used in this article. Upper panel: The ‘standard’ model includes a main disc flaring component with grains of sizes smaller than a critical size a_settling and, possibly, settled dust grains for sizes above this size limit. The internal part of the disc (below r_cav) can harbour a partially filled cavity (where the density is multiplied by a δ_cav < 1 factor). See Sect. 3.5 for details of the other parameters used in the ‘standard model’. Central panel: The extended atmosphere model, or ‘benchmark’ model, detailed in Sect. 3.6, supersedes the ‘standard’ model, while still including its main disc flaring component and settled dust grains. This model comprises an extended tenuous dust atmosphere lying above the classical purely hydrostatic model. Lower panel: The ‘wind’ model, detailed in Sect. 3.7.2, includes all the components from the benchmark model with the addition of a wind whose main parametrisation is shown here. Angles are given from the midplane axis.