Density and Temperature of the Upper Mesosphere and Lower Thermosphere of Mars Retrieved From the OI 557.7 nm Dayglow Measured by TGO/NOMAD
Autor: | S. Aoki, L. Gkouvelis, J.‐C. Gérard, L. Soret, B. Hubert, M. A. Lopez‐Valverde, F. González‐Galindo, H. Sagawa, I. R. Thomas, B. Ristic, Y. Willame, C. Depiesse, J. Mason, M. R. Patel, G. Bellucci, J.‐J. Lopez‐Moreno, F. Daerden, A. C. Vandaele |
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Přispěvatelé: | European Commission, Ministerio de Ciencia e Innovación (España), Belgian Science Policy Office, Fonds de La Recherche Scientifique (Belgique), Agenzia Spaziale Italiana, UK Space Agency |
Jazyk: | angličtina |
Rok vydání: | 2022 |
Předmět: | |
Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
ISSN: | 2169-9100 |
Popis: | The upper mesosphere and lower thermosphere of Mars (70–150 km) is of high interest because it is a region affected by climatological/meteorological events in the lower atmosphere and external solar forcing. However, only a few measurements are available at this altitude range. OI 557.7 nm dayglow emission has been detected at these altitudes by the limb observations with Nadir and Occultation for Mars Discovery (NOMAD) aboard the ExoMars Trace Gas Orbiter (TGO). We develop an inversion method to retrieve density and temperature at these altitudes from the OI 557.7 nm dayglow limb profiles. We demonstrate that the atmospheric density around 90 and 140 km and temperature around 80 km during the daytime can be retrieved from the TGO/NOMAD limb measurements. The retrieved densities show a large seasonal variation both around 90 and 140 km and reach maximum values around perihelion period. This can be explained by temperature variation in the lower atmosphere driven by the dust content and Sun-Mars distance. Temperature around 80 km is higher than predicted by general circulation models, which is tentatively consistent with the warm atmospheric layer recently discovered in nighttime. The temperature retrieval relies on the temperature dependence of the quenching coefficient of 1S oxygen by CO2. Further validation of this coefficient in the range of the Mars upper atmosphere is needed for the verification of the retrieved high temperature. © 2022. American Geophysical Union. All Rights Reserved. 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 (The 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 Ministry of Science and Innovation (MCIU) 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. This work was supported by the Belgian Fonds de la Recherche Scientifique – FNRS under Grant No. 30442502 (ET_HOME). 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). US investigator was supported by the National Aeronautics and Space Administration. F.G.-G. is funded by the Spanish Ministerio de Ciencia, Innovación y Universidades, the Agencia Estatal de Investigación and EC FEDER funds under project RTI2018-100920-J-I00. |
Databáze: | OpenAIRE |
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