Search Publications
The Deuterium Isotopic Ratio of Water Released From the Martian Caps as Measured With TGO/NOMAD
Vandaele, Ann Carine; Brines, Adrian; Aoki, Shohei +18 more
We report vertical profiles of water and D/H for one Martian year as measured with the TGO/NOMAD instrument. The observations were performed via solar occultation, providing water profiles up to ∼100 km and D/H up to ∼60 km, with a vertical resolution of 1-2 km. The measurements reveal dramatic variability of water and D/H over short timescales an…
Global Vertical Distribution of Water Vapor on Mars: Results From 3.5 Years of ExoMars-TGO/NOMAD Science Operations
Aoki, S.; Vandaele, A. C.; Daerden, F. +20 more
We present water vapor vertical distributions on Mars retrieved from 3.5 years of solar occultation measurements by Nadir and Occultation for Mars Discovery onboard the ExoMars Trace Gas Orbiter, which reveal a strong contrast between aphelion and perihelion water climates. In equinox periods, most of water vapor is confined into the low-middle la…
The evidence for unusually high hydrogen abundances in the central part of Valles Marineris on Mars
Mitrofanov, I.; Zelenyi, L.; Malakhov, A. +6 more
Studies of hydrogen deposition in the shallow Martian subsurface have been conducted by two neutron and one gamma-ray detectors in the past and provided global hydrogen maps (Boynton et al., 2002; Feldman et al., 2002; Mitrofanov et al., 2002). It is known from these maps that hydrogen is most abundant in the polar permafrost areas compared to the…
Explaining NOMAD D/H Observations by Cloud-Induced Fractionation of Water Vapor on Mars
Aoki, S.; Vandaele, A. C.; Daerden, F. +25 more
The vertical profiles of water vapor and its semi-heavy hydrogen isotope HDO provided by instruments on ExoMars Trace Gas Orbiter constitute a unique new data set to understand the Martian water cycle including its isotopic composition. As water vapor undergoes hydrogen isotopic fractionation upon deposition (but not sublimation), the D/H isotopic…
A Two Martian Years Survey of Water Ice Clouds on Mars With ACS Onboard TGO
Montmessin, Franck; Trokhimovskiy, Alexander; Korablev, Oleg +7 more
The middle infrared (MIR) channel of the atmospheric chemistry suite (ACS) instrument onboard the ExoMars Trace Gas Orbiter ESA-Roscosmos mission has performed Solar occultation measurements of the Martian atmosphere in the 2.3-4.2 µm spectral range since March 2018, which now covers two Martian years (MY). We use the methodology previously …
Martian Dust Storms and Gravity Waves: Disentangling Water Transport to the Upper Atmosphere
Medvedev, Alexander S.; Yiǧit, Erdal; Hartogh, Paul +2 more
Simulations with the Max Planck Institute Martian general circulation model for Martian years 28 and 34 reveal details of the water "pump" mechanism and the role of gravity wave (GW) forcing. Water is advected to the upper atmosphere mainly by upward branches of the meridional circulation: in low latitudes during equinoxes and over the south pole …
Thermal Structure and Aerosols in Mars' Atmosphere From TIRVIM/ACS Onboard the ExoMars Trace Gas Orbiter: Validation of the Retrieval Algorithm
Grigoriev, A.; Forget, F.; Montmessin, F. +12 more
The Atmospheric Chemistry Suite (ACS) onboard the ExoMars Trace Gas Orbiter monitors the Martian atmosphere through different spectral intervals in the infrared light. We present a retrieval algorithm tailored to the analysis of spectra acquired in nadir geometry by Thermal InfraRed channel in honor of professor Vassilii Ivanovich Moroz (TIRVIM), …
Thermal Tides in the Martian Atmosphere Near Northern Summer Solstice Observed by ACS/TIRVIM Onboard TGO
Montmessin, Franck; Trokhimovskiy, Alexander; Korablev, Oleg +8 more
Thermal tides in the Martian atmosphere are analyzed using temperature profiles retrieved from nadir observations obtained by the TIRVIM Fourier-spectrometer, part of the Atmospheric Chemistry Suite onboard the ExoMars Trace Gas Orbiter. The data is selected near the northern summer solstice at solar longitude (LS) 75°-105° of Martian Y…
Calibration of NOMAD on ESA's ExoMars Trace Gas Orbiter: Part 1 - The Solar Occultation channel
Vandaele, Ann Carine; Neefs, Eddy; Aoki, Shohei +17 more
Nadir and Occultation for MArs Discovery (NOMAD) is a 3-channel spectrometer suite that is currently orbiting Mars onboard ESA's ExoMars Trace Gas Orbiter, measuring the composition of the Martian atmosphere in unprecedented detail. Of the three channels, two operate in the infrared: the Solar Occultation (SO) channel observes gas species in the 2…
Calibration of the NOMAD-UVIS data
Vandaele, Ann Carine; Neefs, Eddy; Aoki, Shohei +23 more
The Ultraviolet and VIsible Spectrometer (UVIS), covering the 200-650 nm range, is one of three spectrometers that comprise the NOMAD instrument on the ExoMars 2016 Trace Gas Orbiter (TGO). UVIS can operate in solar occultation, nadir and limb viewing mode and was designed to monitor ozone and aerosols in the Martian atmosphere. Here, we describe …