Black curve: normalized disk-integrated spectrum of Mars between 1241.52 and 1241.63 cm⁻¹, recorded by TEXES on July 11, 2018 (as in Fig. 12). Colored lines indicate the synthetic spectra calculated with multiple scattering under the conditions of a global dust storm (see Sect. 3.3) for various values of the H₂O₂ vmr: 20 ppbv (red), 15 ppbv (orange), 10 ppbv (green), 5 ppbv (light blue), and 0 ppbv (blue). H₂O₂ is undetected in the TEXES spectrum, with a 2σ upper limit of 10 ppbv.