Nitrous oxide as a function of oxygen and archaeal gene abundance in the North Pacific
Trimmer, M.; Chronopoulou, P.M.; Maanoja, S.T.; Upstill-Goddard, R.C.; Kitidis, V.; Purdy, K.J. (2016). Nitrous oxide as a function of oxygen and archaeal gene abundance in the North Pacific. Nature Comm. 7(13451): 10 pp. http://dx.doi.org/10.1038/ncomms13451
In: Nature Communications. Nature Publishing Group: London. ISSN 2041-1723; e-ISSN 2041-1723, more
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| Authors | | Top |
- Trimmer, M.
- Chronopoulou, P.M.
- Maanoja, S.T.
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- Upstill-Goddard, R.C.
- Kitidis, V.
- Purdy, K.J.
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| Abstract |
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 mu mol O-2 l(-1) within and below the oxycline using (NO2-)-N-15, 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 (N2O)-N-45 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. |
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