On the detection of a high-altitude peak of atmospheric ozone by the NOMAD/UVIS onboard the ExoMars TGO
- 1NASA Goddard Space Flight Center, Greenbelt, Maryland, USA.
- 2Centre for Research and Exploration in Space Science and Technology II, University of Maryland, USA.
- 3Space Science Institute, Boulder, Colorado, USA.
- 4Royal Belgian Institute for Space Aeronomy BIRA-IASB, Brussels, Belgium.
- 5Department of Physical Sciences, The Open University, Milton Keynes, UK.
- 6Instituto di Astrofisica e Planetologia Spaziali, IAPS‐INAF, Rome, Italy.
- 7Instituto de Astrofisica de Andalucia, IAA‐CSIC, Glorieta de la Astronomia, Granada, Spain.
The Nadir and Occultation for MArs Discovery (NOMAD) is a spectrometer suite onboard the ExoMars Trace Gas Orbiter (TGO), providing observations in the nadir, limb, and solar occultation modes since April 2018. UVIS, a single spectrometer unit within NOMAD spans the ultraviolet-visible range between 200 nm and 650 nm. It obtained ~ 4000 vertically resolved (< 1 km) solar occultation observations of the martian atmosphere for over a full Mars year (MY, 687 days) starting at MY 34 during late northern summer at Ls = 163°. Ozone (O3), a principal component of the martian atmosphere, is highly responsive to the incoming UV flux, and is a sensitive tracer of the odd hydrogen chemistry. Transmittance spectra returned by UVIS sampled the O3 Hartley band around 250 nm and provided unique insights into understanding the vertical, latitudinal and temporal behavior of O3. UVIS detected a high-altitude peak of O3 between 40 and 60 km that is mostly persistent between Ls = 340° and ~ 200° at polar latitudes, and is found to be highly dependent on latitude and season. We will present high-resolution results tracking the vertical, latitudinal, diurnal and seasonal evolution of the secondary peak of ozone for a full Mars year. In comparison, we will also provide O3 simulations from the GEM-Mars General Circulation Model (GCM) with the purpose of shedding light into understanding the photochemical processes that lead to the presence and disappearance of the high-altitude peak of atmospheric ozone.
How to cite: Khayat, A., Smith, M., Wolff, M., Daerden, F., Patel, M., Piccialli, A., Vandaele, A. C., Thomas, I., Mason, J., Willame, Y., Bellucci, G., Depiesse, C., and Lopez-Moreno, J. J.: On the detection of a high-altitude peak of atmospheric ozone by the NOMAD/UVIS onboard the ExoMars TGO, Europlanet Science Congress 2020, online, 21 Sep–9 Oct 2020, EPSC2020-362, https://doi.org/10.5194/epsc2020-362, 2020.
