Solid black lines: synthetic spectra for the thin-cloud configuration (see Table 2). Coloured lines: synthetic spectra for the configurations that result from perturbing each of the elements of the six-dimensional atmospheric vector p = {τ_c, Δ_c, τ_{c →TOA}, r_eff, ω₀, } one at a time and according to the values listed in Table 1. The colour code is described in the legends for the lowermost and uppermost values of each parameter, with the other colours corresponding to the intermediate parameter values. The value of Δ_c is given in H_g units and r_eff in μm.