Search Publications
Impacts of Heterogeneous Chemistry on Vertical Profiles of Martian Ozone
Vandaele, A. C.; Villanueva, G. L.; Liuzzi, G. +7 more
We show a positive vertical correlation between ozone and water ice using a vertical cross-correlation analysis with observations from the ExoMars Trace Gas Orbiter's Nadir and Occultation for Mars Discovery instrument. This is particularly apparent during LS = 0°-180°, Mars Year 35 at high southern latitudes, when the water vapor abund…
Water Vapor on Mars: A Refined Climatology and Constraints on the Near-Surface Concentration Enabled by Synergistic Retrievals
Montmessin, Franck; Trokhimovskiy, Alexander; Korablev, Oleg +8 more
With the utilization of a novel synergistic approach, we constrain the vertical distribution of water vapor on Mars with measurements from nadir-pointing instruments. Water vapor column abundances were retrieved simultaneously with PFS (sensing the thermal infrared range) and SPICAM (sensing the near-infrared range) on Mars Express, yielding disti…
Seasonal Changes in the Vertical Structure of Ozone in the Martian Lower Atmosphere and Its Relationship to Water Vapor
Forget, F.; Montmessin, F.; Korablev, O. +13 more
The mid-infrared channel of the Atmospheric Chemistry Suite (ACS MIR) onboard the ExoMars Trace Gas Orbiter is capable of observing the infrared absorption of ozone (O3) in the atmosphere of Mars. During solar occulations, the 003←000 band (3,000-3,060 cm−1) is observed with spectral sampling of ∼0.045 cm−1. Around…
Reappraising the Production and Transfer of Hydrogen Atoms From the Middle to the Upper Atmosphere of Mars at Times of Elevated Water Vapor
Montmessin, F.; Fedorova, A. A.; Lefèvre, F. +7 more
Water escape on Mars has recently undergone a paradigm shift with the discovery of unexpected seasonal variations in the population of hydrogen atoms in the exosphere where thermal escape occurs and results in water lost to space. This discovery led to the hypothesis that, contradicting the accepted pathway, atomic hydrogen in the exosphere was no…
Thermal Structure of the Middle and Upper Atmosphere of Mars From ACS/TGO CO2 Spectroscopy
Montmessin, F.; Fedorova, A. A.; Olsen, K. S. +6 more
Temperature and density in the upper Martian atmosphere, above ∼100 km, are key diagnostic parameters to study processes of the species' escape, investigate the impact of solar activity, model the atmospheric circulation, and plan spacecraft descent or aerobraking maneuvers. In this paper, we report vertical profiling of carbon dioxide (CO2
Mapping the Brightness of Ganymede's Ultraviolet Aurora Using Hubble Space Telescope Observations
Saur, J.; Strobel, D. F.; Roth, L. +4 more
We analyze Hubble Space Telescope observations of Ganymede made with the Space Telescope Imaging Spectrograph between 1998 and 2017 to generate a brightness map of Ganymede's oxygen emission at 1,356 Å. Our Mercator projected map demonstrates that the brightness along Ganymede's northern and southern auroral ovals strongly varies with longitude. T…
The HDO Cycle on Mars: Comparison of ACS Observations With GCM Simulations
Montmessin, Franck; Trokhimovskiy, Alexander; Alday, Juan +10 more
The D/H ratio and its implications on the atmospheric escape, make it an essential observable to study the current and past inventory of water on Mars. With the arrival of the Trace Gas Orbiter around Mars, new measurements of the D/H ratio are now available and require tools to interpret the observations and understand the HDO cycle. We here pres…
Climatology of the CO Vertical Distribution on Mars Based on ACS TGO Measurements
Montmessin, Franck; Trokhimovskiy, Alexander; Alday, Juan +13 more
Carbon monoxide is a non-condensable gas in the Martian atmosphere produced by the photolysis of CO2. Its abundance responds to the condensation and sublimation of CO2 from the polar caps, resulting in seasonal variations of the CO mixing ratio. ACS onboard the ExoMars Trace Gas Orbiter have measured CO in infrared bands by s…
Vertical Aerosol Distribution and Mesospheric Clouds From ExoMars UVIS
Vandaele, Ann Carine; Daerden, Frank; Ristic, Bojan +12 more
The vertical opacity structure of the martian atmosphere is important for understanding the distribution of ice (water and carbon dioxide) and dust. We present a new data set of extinction opacity profiles from the NOMAD/UVIS spectrometer aboard the ExoMars Trace Gas Orbiter, covering one and a half Mars Years (MY) including the MY 34 Global Dust …
Martian Atmospheric Thermal Structure and Dust Distribution During the MY 34 Global Dust Storm From ACS TIRVIM Nadir Observations
Forget, F.; Montmessin, F.; Korablev, O. +14 more
The Thermal InfraRed channel in honor of professor Vassili Ivanovich Moroz (TIRVIM) of the Atmospheric Chemistry Suite onboard ExoMars Trace Gas Orbiter has continuously monitored the Martian atmosphere from 13 March 2018 until 2 December 2019, covering almost a complete Martian Year (MY). In the nadir mode of observations, infrared spectra obtain…