Retrieval of Martian Atmospheric CO Vertical Profiles From NOMAD Observations During the First Year of TGO Operations

Autor: Ashimananda Modak, Miguel Angel López‐Valverde, Adrian Brines, Aurélien Stolzenbach, Bernd Funke, Francisco González‐Galindo, Brittany Hill, Shohei Aoki, Ian Thomas, Giuliano Liuzzi, Gerónimo Villanueva, Justin Erwin, José Juan Lopez Moreno, Nao Yoshida, Udo Grabowski, Francois Forget, Frank Daerden, Bojan Ristic, Giancarlo Bellucci, Manish Patel, Loic Trompet, Ann‐Carine Vandaele
Přispěvatelé: Ministerio de Ciencia e Innovación (España), European Commission, Belgian Science Policy Office
Rok vydání: 2023
Předmět:
Zdroj: Journal of Geophysical Research: Planets. 128
ISSN: 2169-9100
2169-9097
DOI: 10.1029/2022je007282
Popis: We present CO density profiles up to about 100 km in the Martian atmosphere obtained for the first time from retrievals of solar occultation measurements by the Nadir and Occultation for Mars Discovery (NOMAD) onboard ExoMars Trace Gas Orbiter (TGO). CO is an important trace gas on Mars, as it is controlled by CO2 photolysis, chemical reaction with the OH radicals, and the global dynamics. However, the measurements of CO vertical profiles have been elusive until the arrival of TGO. We show how the NOMAD CO variations describe very well the Mars general circulation. We observe a depletion of CO in the upper troposphere and mesosphere during the peak period, LS = 190°–200°, more pronounced over the northern latitudes, confirming a similar result recently reported by Atmospheric Chemistry Suite onboard TGO. However, in the lower troposphere around 20 km, and at least at high latitudes of the S. hemisphere, NOMAD CO mixing ratios increase over 1,500 ppmv during the GDS (Global Dust Storm) onset. This might be related to the downwelling branch of the Hadley circulation. A subsequent increase in tropospheric CO is observed during the decay phase of the GDS around LS = 210°–250° when the dust loading is still high. This could be associated with a reduction in the amount of OH radicals in the lower atmosphere due to lack of solar insolation. Once the GDS is over, CO steadily decreases globally during the southern summer season. A couple of distinct CO patterns associated with the Summer solstice and equinox circulation are reported and discussed. © 2023. American Geophysical Union. All Rights Reserved.
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 Astrofisica de Andalucia (SEV-2017-0709) and funding by Grant PGC2018-101836-B-100 (MCIU/AEI/FEDER, EU). 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 and from Grant CEX2021-001131-S funded by MCIN/AEI/https://doi.org/10.13039/501100011033. 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) 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. US investigators were supported by the National Aeronautics and Space Administration.
Databáze: OpenAIRE
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