Search Publications
Evidence of rapid hydrogen chloride uptake on water ice in the atmosphere of Mars
Montmessin, Franck; Fedorova, Anna A.; Trokhimovskiy, Alexander +5 more
In 2020, hydrogen chloride (HCl) in the gas phase was discovered in the atmosphere of Mars with the Atmospheric Chemistry Suite (ACS) onboard the Trace Gas Orbiter (TGO) mission (Korablev et al., 2021). Its volume mixing ratio (VMR) shows a seasonal increase of up to 5 ppbv during the perihelion season, followed by a sudden drop to undetectable le…
Evidence for transient morning water frost deposits on the Tharsis volcanoes of Mars
Vandaele, A. C.; Daerden, F.; Ristic, B. +27 more
The present-day water cycle on Mars has implications for habitability and future human exploration. Water ice clouds and water vapour have been detected above the Tharsis volcanic province, suggesting the active exchange of water between regolith and atmosphere. Here we report observational evidence for extensive transient morning frost deposits o…
Observed seasonal changes in Martian hydrogen chloride explained by heterogeneous chemistry
Montmessin, Franck; Trokhimovskiy, Alexander; Korablev, Oleg +7 more
Aims: The aim of this work is to show that the seasonal changes and vertical distribution profiles of hydrogen chloride (HCl) on Mars, as observed by the ExoMars Trace Gas Orbiter, are consistent with the production of gas-phase chlorine atoms from airborne dust and a subsequent rapid uptake of HCl onto water ice particles.
Methods: A 1D…
Climatology and Diurnal Variation of Ozone Column Abundances for 2.5 Mars Years as Measured by the NOMAD-UVIS Spectrometer
Vandaele, A. C.; Daerden, F.; Ristic, B. +14 more
The distribution of Mars ozone (O3) is well established; however, our knowledge on the dayside diurnal variation of O3 is limited. We present measurements of Mars O3 column abundances, spanning Mars Year (MY) 34 to the end of MY 36, by the Ultraviolet and VIsible Spectrometer (UVIS), part of the Nadir and Occultati…
Revised upper limits for abundances of NH3, HCN and HC3N in the Martian atmosphere
Montmessin, F.; Korablev, O.; Fedorova, A. A. +7 more
The Atmospheric Chemistry Suite (ACS) onboard the ExoMars Trace Gas Orbiter (TGO) spacecraft has been studying Mars' atmosphere since 2018. The sensitivity of the middle infrared channel (MIR) allows it to address many ardent topics and it is capable of improving and establishing upper limits for many trace species. In this work we present analysi…
Novel quantitative methods to enable multispectral identification of high-purity water ice exposures on Mars using High Resolution Imaging Science Experiment (HiRISE) images
Munaretto, G.; Dundas, C. M.; Seelos, F. P. +8 more
Reliable detection and characterization of water ice on the Martian surface is pivotal to not only understand its present and past climate, but to also provide valuable information on in-situ resource availability and distribution for future human exploration missions. Ice-rich features are currently identified with visible/near-IR (VNIR), thermal…
Relationships Between HCl, H2O, Aerosols, and Temperature in the Martian Atmosphere: 1. Climatological Outlook
Patel, M. R.; Montmessin, F.; Fedorova, A. A. +15 more
Detecting trace gases such as hydrogen chloride (HCl) in Mars' atmosphere is among the primary objectives of the ExoMars Trace Gas Orbiter (TGO) mission. Terrestrially, HCl is closely associated with active volcanic activity, so its detection on Mars was expected to point to some form of active magmatism/outgassing. However, after its discovery us…
Relationships Between HCl, H2O, Aerosols, and Temperature in the Martian Atmosphere: 2. Quantitative Correlations
Patel, M. R.; Montmessin, F.; Fedorova, A. A. +15 more
The detection of hydrogen chloride (HCl) in the atmosphere of Mars was among the primary objectives of the ExoMars Trace Gas Orbiter (TGO) mission. Its discovery using the Atmospheric Chemistry Suite mid-infrared channel (ACS MIR) showed a distinct seasonality and possible link to dust activity. This paper is part 2 of a study investigating the li…
Glacial sculpting of a martian cratered landscape on the northeastern flank of the Hellas basin
Moore, Jeffrey M.; Wilson, Sharon A.; Howard, Alan D. +2 more
The interiors and exteriors of the >25 km diameter Batson, Nako, Salkhad, and Jori craters (and McCauley crater to a lesser degree) on the northeastern rim of Hellas basin, Mars, were extensively modified by glacio-fluvial and glacio-lacustrine activity during the Middle and Late Amazonian, from some time before 1.4 Ga to the present as reveale…
Observation of the Mars O2 visible nightglow by the NOMAD spectrometer onboard the Trace Gas Orbiter
Vandaele, A. C.; Daerden, F.; Thomas, I. R. +9 more
On Mars, atomic oxygen controls the carbon dioxide radiative cooling of the upper atmosphere and the presence of an ozone layer near the poles. To remotely probe meridional transport of O atoms from the summer to the winter hemisphere and the descending flow in the winter polar regions, the O2 Herzberg II atmospheric emission could be u…