Transmission spectrum of WASP-127b. The GTC/OSIRIS and NOT/ALFOSC measurements are shown in squares and circles with error bars, respectively. A flat line is used to represent the optically thick clouds. The green line shows a representative pure Rayleigh scattering atmosphere. The purple line shows a fiducial atmospheric model with the solar abundance, with Na, K, and H₂ O included, and with an isothermal temperature of 1400 K (Kempton et al. 2017). The red line shows the retrieved model spectrum from our retrieval modeling. The binned models are shown in diamonds. One atmospheric scale height is equivalent to H_eq ∕R_⋆ = 0.00243. All the reduced chi-squares in this plot only simply consider the offset as a free parameter.