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dc.contributor.authorVENOT, Olivia
dc.contributor.authorBOUNACEUR, Roda
dc.contributor.authorDOBRIJEVIC, M.
dc.contributor.authorHÉBRARD, Eric
hal.structure.identifierLaboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics [LESIA]
dc.contributor.authorCAVALIÉ, T.
dc.contributor.authorTREMBLIN, Pascal
hal.structure.identifierSchool of Physics and Astronomy [Exeter]
dc.contributor.authorDRUMMOND, Benjamin
hal.structure.identifierLaboratoire de Météorologie Dynamique (UMR 8539) [LMD]
dc.contributor.authorCHARNAY, Benjamin
dc.date.issued2019
dc.identifier.issn0004-6361
dc.description.abstractEnContext. Three-dimensional models that account for chemistry are useful tools to predict the chemical composition of (exo)planet and brown dwarf atmospheres and interpret observations of future telescopes, such as James Webb Space Telescope (JWST) and Atmospheric Remote-sensing Infrared Exoplanet Large-survey (ARIEL). Recent Juno observations of the NH3 tropospheric distribution in Jupiter also indicate that 3D chemical modelling may be necessary to constrain the deep composition of the giant planets of the solar system. However, due to the high computational cost of chemistry calculations, 3D chemical modelling has so far been limited.Aims. Our goal is to develop a reduced chemical scheme from the full chemical scheme of Venot et al. 2012 (A&A, 546, A43) able to reproduce accurately the vertical profiles of the observable species (H2O, CH4, CO, CO2, NH3, and HCN). This reduced scheme should have a size compatible with three-dimensional models and be usable across a large parameter space (e.g. temperature, pressure, elemental abundance). The absence of C2H2 from our reduced chemical scheme prevents its use to study hot C-rich atmospheres.Methods. We used a mechanism-processing utility program designed for use with Chemkin-Pro to reduce a full detailed mechanism. The ANSYS© Chemkin-Pro Reaction Workbench allows the reduction of a reaction mechanism for a given list of target species and a specified level of accuracy. We took a warm giant exoplanet with solar abundances, GJ 436b, as a template to perform the scheme reduction. To assess the validity of our reduced scheme, we took the uncertainties on the reaction rates into account in Monte Carlo runs with the full scheme, and compared the resulting vertical profiles with the reduced scheme. We explored the range of validity of the reduced scheme even further by applying our new reduced scheme to GJ 436b’s atmosphere with different elemental abundances, to three other exoplanet atmospheres (GJ 1214b, HD 209458b, HD 189733b), a brown dwarf atmosphere (SD 1110), and to the troposphere of two giant planets of the solar system (Uranus and Neptune).Results. For all cases except one, the abundances predicted by the reduced scheme remain within the error bars of the model with the full scheme. Expectedly, we found important differences that cannot be neglected only for the C-rich hot atmosphere. The reduced chemical scheme allows more rapid runs than the full scheme from which it is derived (~30× faster).Conclusions. We have developed a reduced scheme containing 30 species and 181 reversible reactions. This scheme has a large range of validity and can be used to study all kinds of warm atmospheres, except hot C-rich ones that contain a high amount of C2H2. It can be used in 1D models, for fast computations, but also in 3D models for hot giant (exo)planet and brown dwarf atmospheres.
dc.language.isoen
dc.publisherEDP Sciences
dc.subject.enAstrophysics - Earth and Planetary Astrophysics
dc.subject.enastrochemistry
dc.subject.enplanets and satellites: atmospheres
dc.subject.enplanets and satellites: composition
dc.subject.enmethods: numerical
dc.subject.enplanets and satellites: gaseous planets
dc.subject.enbrown dwarfs
dc.title.enReduced chemical scheme for modelling warm to hot hydrogen-dominated atmospheres
dc.typeArticle de revue
dc.identifier.doi10.1051/0004-6361/201834861
dc.subject.halPhysique [physics]
dc.subject.halPhysique [physics]/Astrophysique [astro-ph]
dc.identifier.arxiv1902.04939
bordeaux.journalAstronomy and Astrophysics - A&A
bordeaux.pageA58
bordeaux.volume624
bordeaux.peerReviewedoui
hal.identifierhal-02051741
hal.version1
hal.popularnon
hal.audienceInternationale
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-02051741v1
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