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Lookup NU author(s): Professor Robert Upstill-GoddardORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
Oceanic oxygen minimum zones are strong sources of the potent greenhouse gas N2O but its microbial source is unclear. We characterized an exponential response in N2O production to decreasing oxygen between 1 and 30 mmol O2 l1 within and below the oxycline using 15NO2 , a relationship that held along a 550 km offshore transect in the North Pacific. Differences in the overall magnitude of N2O production were accounted for by archaeal functional gene abundance. A one-dimensional (1D) model, parameterized with our experimentally derived exponential terms, accurately reproduces N2O profiles in the top 350m of water column and, together with a strong 45N2O signature indicated neither canonical nor nitrifier–denitrification production while statistical modelling supported production by archaea, possibly via hybrid N2O formation. Further, with just archaeal N2O production, we could balance high-resolution estimates of sea-to-air N2O exchange. Hence, a significant source of N2O, previously described as leakage from bacterial ammonium oxidation, is better described by low-oxygen archaeal production at the oxygen minimum zone’s margins.
Author(s): Trimmer M, Chronopoulou PM, Maanoja ST, Upstill-Goddard RC, Kitidis V, Purdy KJ
Publication type: Article
Publication status: Published
Journal: Nature Communications
Print publication date: 01/12/2016
Online publication date: 01/12/2016
Acceptance date: 05/10/2016
Date deposited: 06/10/2016
ISSN (electronic): 2041-1723
Publisher: Nature Publishing Group
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