Constraints on global oceanic emissions of N2O from observations and models

Buitenhuis, Erik T. ORCID: https://orcid.org/0000-0001-6274-5583, Suntharalingam, Parvadha and Le Quéré, Corinne ORCID: https://orcid.org/0000-0003-2319-0452 (2018) Constraints on global oceanic emissions of N2O from observations and models. Biogeosciences, 15 (7). pp. 2161-2175. ISSN 1726-4189

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Abstract

We estimate the global ocean N2O flux to the atmosphere and its confidence interval using a statistical method based on model perturbation simulations and their fit to a database of ΔpN2O (n =  6136). We evaluate two submodels of N2O production. The first submodel splits N2O production into oxic and hypoxic pathways following previous publications. The second submodel explicitly represents the redox transformations of N that lead to N2O production (nitrification and hypoxic denitrification) and N2O consumption (suboxic denitrification), and is presented here for the first time. We perturb both submodels by modifying the key parameters of the N2O cycling pathways (nitrification rates; NH4+ uptake; N2O yields under oxic, hypoxic and suboxic conditions) and determine a set of optimal model parameters by minimisation of a cost function against four databases of N cycle observations. Our estimate of the global oceanic N2O flux resulting from this cost function minimisation derived from observed and model ΔpN2O concentrations is 2.4 ± 0.8 and 2.5 ± 0.8 Tg N yr−1 for the two N2O submodels. These estimates suggest that the currently available observational data of surface ΔpN2O constrain the global N2O flux to a narrower range relative to the large range of results presented in the latest IPCC report.

Item Type: Article
Uncontrolled Keywords: sdg 13 - climate action ,/dk/atira/pure/sustainabledevelopmentgoals/climate_action
Faculty \ School: Faculty of Science > School of Environmental Sciences
University of East Anglia Research Groups/Centres > Theme - ClimateUEA
UEA Research Groups: Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences
University of East Anglia Schools > Faculty of Science > Tyndall Centre for Climate Change Research
Faculty of Science > Research Centres > Tyndall Centre for Climate Change Research
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Depositing User: Pure Connector
Date Deposited: 18 Apr 2018 08:31
Last Modified: 13 Apr 2023 13:54
URI: https://ueaeprints.uea.ac.uk/id/eprint/66798
DOI: 10.5194/bg-15-2161-2018

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