The volume fraction of the different constituents of the dirty particles produced by drift-phoenix for the two model atmospheres. The horizontal dotted lines indicate altitudes where the composition of the particles changes rapidly, which is where we have chosen the boundaries between the four different particle types. The particle types can be described as: 1 – high silicate haze; 2 – low silicate haze; 3 – iron cloud; 4 – Al₂O₃ cloud. The altitude independent composition that we assume for each particle type is indicated by vertical dashed, coloured lines (see Table 2).