ExoMars TGO/NOMAD‐UVIS Vertical Profiles of Ozone: 1. Seasonal Variation and Comparison to Water

We present ∼1.5 Mars Years (MY) of ozone vertical profiles, covering LS = 163° in MY34 to 320° MY35, a period which includes the 2018 global dust storm. Since April 2018, Ultraviolet and Visible Spectrometer channel Nadir Occultation for Discovery (NOMAD) instrument aboard ExoMars Trace Gas Orbiter has observed vertical, latitudinal seasonal distributions ozone. Around perihelion, relative abundance both water (from coincident NOMAD measurements) increases with decreasing altitude below ∼40 km. aphelion, localized decreases exist between 25 35 km location modeled peak abundances. High-latitude (>±55°), high (40–55 km) equinoctial enhancements are hemispheres (LS ∼350°–40°) discussed companion article this work (Khayat et al., 2021). The descending branch main Hadley cell shapes distribution at 40°–60°, possible signature northern hemisphere thermally indirect identifiable from 40°–80°. Morning terminator observations show elevated abundances respect evening observations, average 20 40 an order magnitude higher sunrise compared sunset, attributed diurnal photochemical partitioning along line sight O or fluctuations abundance. retrievals presented here provide most complete description date as function season latitude.