Distribution of T (left) and ΔT (right) as a function of the altitude from the solar surface, defined as the photosphere level R_⊙,opt. The respective shaded area indicates the 1σ error of these distributions. The black line indicates the theoretical T distribution of the original eSSC model. The blue vertical line indicates the altitude, h_SSC, below which the SSC model is defined. The y-axis of these plots is shown in logarithmic scale. The best-fit T distribution is compatible (within an uncertainty ≲25%) with the original eSSC model below ∼100 Mm. Above this altitude, this distribution is characterised by strong degeneracy.