Publications by authors named "Arnaud Mahieux"
Unexpected increase of the deuterium to hydrogen ratio in the Venus mesosphere.
Proc Natl Acad Sci U S A
August 2024
Article Synopsis
- This study focuses on the analysis of water (HO) and heavy water (HDO) profiles in the mesosphere of Venus using data from Venus Express, revealing significant increases in both substances and a notable rise in the D/H ratio with altitude.
- Two main hypotheses are proposed to explain these changes: isotopic fractionation due to photolysis or phase change processes connected to sulfuric acid aerosols, with the latter accounting for the observed rapid changes in water vapor and aerosols.
- The findings imply that the varying altitudes are essential for understanding Venus's deuterium and hydrogen reservoirs, and that these altitude changes directly impact the rates at which hydrogen and deuterium escape, suggesting a need for evolutionary models to factor in
The surname of author Cathy Quantin-Nataf was misspelled 'Quantin-Nata' , authors Ehouarn Millour and Roland Young were missing from the ACS Science Team list, and minor changes have been made to the author and affiliation lists; see accompanying Amendment. These errors have been corrected online.
View Article and Find Full Text PDFGlobal dust storms on Mars are rare but can affect the Martian atmosphere for several months. They can cause changes in atmospheric dynamics and inflation of the atmosphere, primarily owing to solar heating of the dust. In turn, changes in atmospheric dynamics can affect the distribution of atmospheric water vapour, with potential implications for the atmospheric photochemistry and climate on Mars.
View Article and Find Full Text PDFThe Solar Occultation in the InfraRed (SOIR) instrument onboard the ESA Venus Express spacecraft, an infrared spectrometer sensitive from 2.2 to 4.3 μm, probed the atmosphere of Venus from June 2006 until December 2014.
View Article and Find Full Text PDFThe SOIR instrument on board the ESA Venus Express mission has been operational since the insertion of the satellite around Venus in April 2006. Since then, it has delivered high quality IR solar occultation spectra of the atmosphere of Venus. The different steps from raw spectra to archived data are described and explained in detail here.
View Article and Find Full Text PDFSolar occultation in the infrared, part of the Spectoscopy for Investigation of Characteristics of the Atmosphere of Venus (SPICAV) instrument onboard Venus Express, combines an echelle grating spectrometer with an acousto-optic tunable filter (AOTF). It performs solar occultation measurements in the IR region at high spectral resolution. The wavelength range probed allows a detailed chemical inventory of Venus's atmosphere above the cloud layer, highlighting the vertical distribution of gases.
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