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A new mechanistic framework to predict OCS fluxes from soils

hal.structure.identifierInteractions Sol Plante Atmosphère [UMR ISPA]
dc.contributor.authorOGÉE, Jérôme
hal.structure.identifierInteractions Sol Plante Atmosphère [UMR ISPA]
dc.contributor.authorSAUZE, Joana
hal.structure.identifierMax Planck Institute for Chemistry [MPIC]
dc.contributor.authorKESSELMEIER, Jurgen
hal.structure.identifierBiologie végétale et microbiologie environnementale - UMR7265 [BVME]
dc.contributor.authorGENTY, Bernard
hal.structure.identifierUniversity of California [Merced] [UC Merced]
dc.contributor.authorWHELAN, Mary
hal.structure.identifierInteractions Sol Plante Atmosphère [UMR ISPA]
dc.contributor.authorLAUNOIS, Thomas
hal.structure.identifierInteractions Sol Plante Atmosphère [UMR ISPA]
dc.contributor.authorWINGATE, Lisa
dc.date.accessioned2024-04-08T12:10:08Z
dc.date.available2024-04-08T12:10:08Z
dc.date.issued2015
dc.date.conference2015-12-14
dc.identifier.urihttps://oskar-bordeaux.fr/handle/20.500.12278/196612
dc.description.abstractEnA better description of the amplitude of photosynthetic and respiratory gross CO2 fluxes at large scales is needed to improve our predictions of the current and future global CO2 cycle. Carbonyl sulphide (OCS) has been proposed as a new tracer of gross photosynthesis (GPP), as the uptake of OCS from the atmosphere is dominated by the activity of carbonic anhydrase (CA), an enzyme abundant in leaves that also catalyses CO2 hydration during photosynthesis. But soils also exchange OCS with the atmosphere which complicates the retrieval of GPP from atmospheric budgets. Indeed soils can take up large amounts of OCS from the atmosphere as soil microorganisms also contain CA, and OCS emissions from soils have been reported in agricultural or anoxic soils. To date no mechanistic framework exists to describe this exchange of OCS between soils and the atmosphere but empirical results, once up-scaled to the global scale, indicate that OCS consumption by soils dominates over production and its contribution to the atmospheric budget is large, at about one third of the OCS uptake by vegetation, with also a large uncertainty. Here, we propose a new mechanistic model of the exchange of OCS between soils and the atmosphere that builds on our knowledge of soil CA activity from CO2 oxygen isotopes. In this model the OCS soil budget is described by a first-order reaction-diffusion-production equation, assuming that the hydrolysis of OCS by CA is total and irreversible. Using this model we are able to explain the observed presence of an optimum temperature for soil OCS uptake and show how this optimum can shift to cooler temperatures in the presence of soil OCS emissions. Our model can also explain the observed optimum with soil moisture content previously described in the literature as a result of diffusional constraints on OCS hydrolysis. In order to simulate the exact OCS uptake rates and patterns observed on several soils collected from a range of biomes, different CA activities had to be evoked in each soil type, coherent with that for CO2 isotopes given the differences in affinity of CA for both trace gases.
dc.language.isoen
dc.subjectsulfure de carbonyle
dc.subjectanhydrase carbonique
dc.subjectisotope du carbone
dc.subjectéchange sol atmosphère
dc.subject.encarbonic anhydrase
dc.subject.encarbon isotopes
dc.title.enA new mechanistic framework to predict OCS fluxes from soils
dc.typeCommunication dans un congrès
dc.subject.halSciences de l'environnement/Milieux et Changements globaux
bordeaux.pagenp
bordeaux.hal.laboratoriesInteractions Soil Plant Atmosphere (ISPA) - UMR 1391*
bordeaux.institutionBordeaux Sciences Agro
bordeaux.institutionINRAE
bordeaux.conference.titleAGU Fall meeting
bordeaux.countryUS
bordeaux.conference.citySan Francisco
bordeaux.peerReviewedoui
hal.identifierhal-01595441
hal.version1
hal.invitednon
hal.proceedingsoui
hal.conference.end2015-12-18
hal.popularnon
hal.audienceNon spécifiée
hal.origin.linkhttps://hal.archives-ouvertes.fr//hal-01595441v1
bordeaux.COinSctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.date=2015&rft.spage=np&rft.epage=np&rft.au=OG%C3%89E,%20J%C3%A9r%C3%B4me&SAUZE,%20Joana&KESSELMEIER,%20Jurgen&GENTY,%20Bernard&WHELAN,%20Mary&rft.genre=unknown


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