This is the NASA repository of the ExoMars/NOMAD instrument data (PI:Vandaele, IASB-BIRA, Belgium). The Nadir and Occultation for MArs Discovery (NOMAD) instrument is part of the payload of the ExoMars Trace Gas Orbiter 2016. It conducts a spectroscopic survey of Mars' atmosphere in UV, visible and IR wavelengths covering the 0.2-0.65 and 2-4.7 μm spectral ranges. NOMAD is composed of 3 channels: a solar occultation only channel (SO) operating in the infrared wavelength domain, a second infrared channel capable of doing nadir, but also solar occultation and limb observations (LNO), and an ultraviolet/visible channel (UVIS) that can work in all observation modes.|
NASA-GSFC team: Villanueva (co-I), Mumma (co-I), Smith (co-I), Liuzzi, Crismani, Knutsen, Khayat
|Available Datasets associated to NOMAD publications|
Strong variability of Martian water ice clouds during dust storms revealed from ExoMars Trace Gas Orbiter/NOMAD|
Journal of Geophysical Research (JGR) Planets, 2019-2020 (Under review)
Giuliano Liuzzi, Geronimo L. Villanueva, Matteo M. J. Crismani, Michael D. Smith, Michael J. Mumma, Frank Daerden, Shohei Aoki, Ann Carine Vandaele, R. Todd Clancy, Justin Erwin, Ian Thomas, Bojan Ristic, José-Juan Lopez-Moreno , Giancarlo Bellucci, Manish R. Patel
Observations of water ice clouds and aerosols on Mars can provide important insights into the complexity of the water cycle. Recent observations have indicated an important link between dust activity and the water cycle, as intense dust activity can significantly raise the hygropause, and subsequently increase the escape of water after dissociation in the upper atmosphere. Here present observations from NOMAD/TGO that investigate the variation of water ice clouds in the perihelion season of Mars Year 34 (April 2018-19), their diurnal and seasonal behavior, and the vertical structure and microphysical properties of water ice and dust. These observations reveal the recurrent presence of a layer of mesospheric water ice clouds subsequent to the 2018 Global Dust Storm. We show that this layer rose from 45 to 80 km in altitude on a timescale of days from heating in the lower atmosphere due to the storm. In addition, we demonstrate that there is a strong dawn dusk asymmetry in water ice abundance, related to nighttime nucleation and subsequent daytime sublimation. Water ice particle sizes are retrieved consistently and exhibit sharp vertical gradients (from 0.1 to 4.0 um), as well as mesospheric differences between the Global Dust Storm (<0.5 um) and the 2019 regional dust storm (1.0 um), which suggests differing water ice nucleation efficiencies. These results form the basis to advance our understanding of mesospheric water ice clouds on Mars, and further constrain the interactions between water ice and dust in the middle atmosphere.
Retrieved dust and water ice concentration and particle size over time Files: 8 (compressed to 5.5 Mbytes)