Panel (a): overview of absorption cross sections (cm²/molecule) of methane in the tetradecad range 5400–6300 cm⁻¹ at four temperatures, T = 295, 400, 600, and 1000 K: low resolution (R = 2 cm⁻¹) simulations of observations (up) and theory (down). Panel (b): absorption cross sections (cm²/molecule) of methane in the strong absorbing range around 6000 cm⁻¹ at eight temperatures, T = 295, 300, 400, 500, 600, 700, 800, 900, and 1000 K: low resolution (R = 2 cm⁻¹) simulations of observations (up) and theory (down). Dominant absorption features are clearly temperature-dependent, and their relative strengths could be used for fast temperature retrievals.