Tipper opacity simulations. The black dots indicate values extracted from the AM simulations. The lines correspond to weighted quadratic fits to the simulated data and for each T_gnd. Upper panel: situation for the Chajnantor Plateau, while lower panel: data and fits for the summit of Cerro Chajnantor. The blue (red) line in the middle of the distribution corresponds to the results for the average ground temperature at the plateau (Cerro Chajnantor) of 272.4 K (268.6 K), as previously used in Cortés et al. (2016).