Abstract :
[en] Following the recent detection of HCl in the atmosphere of Mars by ExoMars/Trace Gas Orbiter, we present here the first measurement of the 37Cl/35Cl isotopic ratio in the Martian atmosphere using a set of Nadir Occultation for MArs Discovery (NOMAD) observations. We determine an isotopic anomaly of −6 ± 78‰ compared to Earth standard, consistent with the −51‰–−1‰ measured on Mars’ surface by Curiosity. The measured isotopic ratio is also consistent with surface measurements, and suggests that Cl reservoirs may have undergone limited processing since formation in the Solar Nebula. The examination of possible sources and sinks of HCl shows only limited pathways to short-term efficient Cl fractionation and many plausible reservoirs of “light” Cl.
Funding text :
ExoMars is a space mission of the European Space Agency (ESA) and Roscosmos. The NOMAD experiment is led by the Royal Belgian Institute for Space Aeronomy (IASB-BIRA), assisted by Co-PI teams from Spain (IAA-CSIC), Italy (INAF-IAPS), and the United Kingdom (Open University). This project acknowledges funding by the Belgian Science Policy Office (BELSPO), with the financial and contractual coordination by the ESA Prodex Office (PEA 4000103401, 4000121493), by the Spanish MICINN through its Plan Nacional and by European funds under grants PGC2018-101836-B-I00 and ESP2017-87143-R (MINECO/FEDER), as well as by UK Space Agency through grants ST/V002295/1, ST/V005332/1 and ST/S00145X/1 and Italian Space Agency through grant 2018-2-HH.0. The IAA/CSIC team acknowledges financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709), and the CBK PAN team from the EXOMHYDR project, carried out within the TEAM program of the Foundation for Polish Science cofinanced by the European Union under the European Regional Development Fund (TEAM/2016-3/20). This work was supported by NASA's Mars Program Office under WBS 604796, “Participation in the TGO/NOMAD Investigation of Trace Gases on Mars” and by NASA's SEEC initiative under Grant Number NNX17AH81A, “Remote sensing of Planetary Atmospheres in the Solar System and Beyond.” U.S. investigators were supported by the National Aeronautics and Space Administration. S. Viscardy acknowledges support from the Belgian Fonds de la Recherche Scientifique-FNRS under grant numbers 30442502 (ET_HOME) and Belgian Science Policy Office BrainBe MICROBE Projects. S. Aoki is “Chargé de Recherches” at the F.R.S-FNRS. F. Schmidt acknowledges support from the “Institut National des Sciences de l'Univers” (INSU), the "Center National de la Recherche Scientifique" (CNRS) and "Center National d'Etudes Spatiales" (CNES) through the “Program National de Planétologie”. S. Robert thanks BELSPO for the FED-tWIN funding (Prf-2019-077-RT-MOLEXO).ExoMars is a space mission of the European Space Agency (ESA) and Roscosmos. The NOMAD experiment is led by the Royal Belgian Institute for Space Aeronomy (IASB‐BIRA), assisted by Co‐PI teams from Spain (IAA‐CSIC), Italy (INAF‐IAPS), and the United Kingdom (Open University). This project acknowledges funding by the Belgian Science Policy Office (BELSPO), with the financial and contractual coordination by the ESA Prodex Office (PEA 4000103401, 4000121493), by the Spanish MICINN through its Plan Nacional and by European funds under grants PGC2018‐101836‐B‐I00 and ESP2017‐87143‐R (MINECO/FEDER), as well as by UK Space Agency through grants ST/V002295/1, ST/V005332/1 and ST/S00145X/1 and Italian Space Agency through grant 2018‐2‐HH.0. The IAA/CSIC team acknowledges financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV‐2017‐0709), and the CBK PAN team from the EXOMHYDR project, carried out within the TEAM program of the Foundation for Polish Science cofinanced by the European Union under the European Regional Development Fund (TEAM/2016‐3/20). This work was supported by NASA's Mars Program Office under WBS 604796, “Participation in the TGO/NOMAD Investigation of Trace Gases on Mars” and by NASA's SEEC initiative under Grant Number NNX17AH81A, “Remote sensing of Planetary Atmospheres in the Solar System and Beyond.” U.S. investigators were supported by the National Aeronautics and Space Administration. S. Viscardy acknowledges support from the Belgian Fonds de la Recherche Scientifique‐FNRS under grant numbers 30442502 (ET_HOME) and Belgian Science Policy Office BrainBe MICROBE Projects. S. Aoki is “Chargé de Recherches” at the F.R.S‐FNRS. F. Schmidt acknowledges support from the “Institut National des Sciences de l'Univers” (INSU), the "Center National de la Recherche Scientifique" (CNRS) and "Center National d'Etudes Spatiales" (CNES) through the “Program National de Planétologie”. S. Robert thanks BELSPO for the FED‐tWIN funding (Prf‐2019‐077‐RT‐MOLEXO).
Scopus citations®
without self-citations
4