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The vertical distribution of ozone in Mars Years 34-35 from ExoMars TGO/NOMAD-UVIS observations
  • +23
  • Manish R Patel,
  • Graham Sellers,
  • J. Mason,
  • James Andrew Holmes,
  • Megan Brown,
  • Stephen Lewis,
  • Kylash Rajendran,
  • Paul Michael Streeter,
  • Charlotte Marriner,
  • Brijen Hathi,
  • David Slade,
  • Mark Leese,
  • Michael J. Wolff,
  • Alain SJ Khayat,
  • Michael D. Smith,
  • Shohei AOKI,
  • Arianna Piccialli,
  • Ann Carine Vandaele,
  • Frank W. Daerden,
  • Severine Robert,
  • Ian Richard Thomas,
  • Bojan Ristic,
  • Yannick Willame,
  • Cédric Depiesse,
  • Giancarlo Bellucci,
  • José Juan López-Moreno
Manish R Patel
The Open University

Corresponding Author:[email protected]

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Graham Sellers
The Open University
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J. Mason
Open University
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James Andrew Holmes
Open University
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Megan Brown
The Open University
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Stephen Lewis
Open University
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Kylash Rajendran
The Open University
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Paul Michael Streeter
Open University
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Charlotte Marriner
The Open University
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Brijen Hathi
The Open University
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David Slade
The Open University
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Mark Leese
The Open University
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Michael J. Wolff
Space Science Institute
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Alain SJ Khayat
NASA Goddard Space Flight Center and the University of Maryland
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Michael D. Smith
NASA Goddard Space Flight Center
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Shohei AOKI
Royal Belgian Institute for Space Aeronomy
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Arianna Piccialli
Belgian Institute for Space Aeronomy (BIRA-IASB)
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Ann Carine Vandaele
Royal Belgian Institute for Space Aeronomy
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Frank W. Daerden
Royal Belgian Institute for Space Aeronomy BIRA-IASB
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Severine Robert
Royal Belgian Institute for Space Aeronomy, BIRA-IASB
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Ian Richard Thomas
Belgian Institute for Space Aeronomy
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Bojan Ristic
Royal Belgian Institute for Space Aeronomy
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Yannick Willame
Belgian Institute For Space Aeronomy
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Cédric Depiesse
Royal Belgian Institute for Space Aeronomy
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Giancarlo Bellucci
Institute for Space Astrophysics and Planetology
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José Juan López-Moreno
Instituto de Astrofisica de Andalucia, IAA-CSIC
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Abstract

We present ~1.5 Mars Years (MY) of ozone vertical profiles, covering Ls = 163deg; in MY34 to Ls = 320deg; in MY35, a period which includes the 2018 global dust storm. Since April 2018, the Ultraviolet and Visible Spectrometer (UVIS) channel of the Nadir and Occultation for Mars Discovery (NOMAD) spectrometer aboard the ExoMars Trace Gas Orbiter has observed the vertical, latitudinal and seasonal distributions of ozone. Around perihelion, the relative abundance of ozone (and water from coincident NOMAD measurements) increases strongly together below ~40 km. Around aphelion, decreases in ozone abundance exist between 25-35 km coincident with the location of modelled peak water abundances. We report high latitude (above 55deg;), high altitude (40-55 km) equinoctial ozone enhancements in both hemispheres. The northern equinoctial high altitude enhancement is previously unobserved and forms prior to vernal equinox lasting for almost 100 sols (Ls ~350‑40deg), whereas the southern enhancement persists for over twice as long (Ls = ~5-140deg;). Both layers reform at autumnal equinox, with the northern layer at a lower abundance. These layers likely form through a combination of anti-correlation with water and the equinoctial meridional transport of O and H atoms to high-latitude regions. The descending branch of the main Hadley cell shapes the ozone distribution at Ls = 40-60deg;, with the possible signature of a northern hemisphere thermally indirect cell identifiable from Ls = 40-80deg;. The ozone retrievals presented here provide the most complete global description of Mars ozone vertical distributions as a function of season and latitude.