Examples of the spectra used in this work. Top-Left: best fit of the CH₄ emission lines at 69°S with a model without stratospheric hazes (red line) compared to the observed spectra (black line), with an aerosol feature centered at 1450 cm⁻¹. Top-Right: best fit of the C₂H₂ emission lines with a model without stratospheric hazes (red line) compared to the observed spectra (black line), with an aerosol feature centered at 750 cm⁻¹. Bottom-Left: the same as in Top-Right but for the aerosol feature centered at 700 cm⁻¹. Bottom-Right: C₆H₆ v₁₁ spectra inside the auroral oval (red) and outside the auroral oval (black). The vertical lines show the error of the observations.