Examples of SO₂ maps recorded in 2021–2022. Top: maps of the line depth ratio of a weak SO₂ multiplet (around 1345.1 cm⁻¹) to the CO₂ transition at 1345.22 cm⁻¹, recorded in 2021 and 2022 (one map per observing run). Disk-integrated spectra corresponding to these maps are shown in Fig 2. Bottom: maps of the line depth ratio of a weak SO₂ multiplet (around 529.70 cm⁻¹) to the CO₂ transition at 529.81 cm⁻¹, recorded in 2021 and 2022 (one map per observing run). For the 19 µm maps, the maximum scale is 0.7, except for September 2021 for which the maximum scale is 1.2, as indicated below the map. Disk-integrated spectra corresponding to these maps are shown in Fig. 3. The local maxima observed in 2022 near the south pole (bottom right) are instrumental artifacts, due to the nearly isothermal profile at high latitude, which prevents the SO₂ retrieval.