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- Title
Ozone vertical profiles from NOMAD-UVIS: a preliminary analysis.
- Authors
Piccialli, Arianna; Vandaele, Ann Carine; Willame, Yannick; Depiesse, Cedric; Trompet, Loïc; Neary, Lori; Viscardy, Sebastien; Daerden, Frank; Thomas, Ian R.; Ristic, Bojan; Mason, Jon P.; Patel, Manish R.; Bellucci, Giancarlo; Lopez-Moreno, Jose-Juan
- Abstract
Ozone is a highly reactive species on Mars. In particular, it displays steep gradients across the terminator due to photolysis [4]. Odd hydrogen radicals play an important role in the destruction of ozone. This results in a strong anti-correlation between O3 and H2O [4].Here, we will present first retrievals of ozone vertical profiles obtained from NOMAD-UVIS solar occultations. NOMAD will help us improve our knowledge of the climatology of ozone and of its complex photochemistry.The NOMAD (Nadir and Occultation for MArs Discovery) – operating onboard the ExoMars 2016 Trace Gas Orbiter satellite – started to acquire the first scientific measurements on 21 April 2018.It is a spectrometer composed of 3 channels: 1) a solar occultation channel (SO) operating in the infrared (2.3-4.3 μm); 2) a second infrared channel LNO (2.3-3.8 μm) capable of doing nadir, as well as solar occultation and limb; and 3) an ultraviolet/visible channel UVIS (200-650 nm) that can work in the three observation modes [1,2]. The UVIS channel has a spectral resolution <1.5 nm. In the solar occultation mode it is mainly devoted to study the climatology of ozone and aerosols content [3]. We will present first retrievals of ozone vertical profiles. NOMAD-UVIS spectra are simulated using the line-by-line radiative transfer code ASIMUT-ALVL developed at IASB-BIRA [5]. In a preliminary study based on SPICAM-UV solar occultations (See [6]), ASIMUT was modified in order to take into account the atmospheric composition and structure at the day-night terminator. We followed the same method described in [7] to check that the spectra are correctly calibrated and accurately normalized to the solar spectrum. As input for ASIMUT, we used gradients predicted by the 3D GEM-Mars v4 Global Circulation Model (GCM) [8,9] and the UK version of the LMD GCM. UVIS ozone profiles will also be compared to SPICAM-UV retrievals.References:[1] Vandaele, A.C., et al., Planetary and Space Science, Vol. 119, pp. 233–249, 2015. [2] Neefs, E., et al., Applied Optics, Vol. 54 (28), pp. 8494-8520, 2015.[3] M.R. Patel et al., In: Appl. Opt. 56.10 (2017), pp. 2771–2782. DOI: 10.1364/AO.56.002771.[4] Lefèvre, F., et al., Aug. 2008. Nature 454, 971–975.[5] Vandaele, A.C., et al., JGR, 2008. 113 doi:10.1029/2008JE003140.[6] Piccialli, A., EPSC 2018.[7] Trompet, L., et al., 2016. Applied Optics 55, 9275-9281. [8] Neary, L., and F. Daerden (2018), Icarus, 300, 458–476, doi:10.1016/j.icarus.2017.09.028.[9] Daerden, F.; et al., GRL, 2015, 42, 18, 7319-7326.
- Subjects
GENERAL circulation model; OZONE; TRACE gases; ATMOSPHERIC composition; PLANETARY science; SOLAR spectra; SOLAR ultraviolet radiation
- Publication
Geophysical Research Abstracts, 2019, Vol 21, p1
- ISSN
1029-7006
- Publication type
Article