Impact of intensifying nitrogen limitation on ocean net primary production is fingerprinted by nitrogen isotopes



Buchanan, Pearse J ORCID: 0000-0001-7142-882X, Aumont, Olivier, Bopp, Laurent, Mahaffey, Claire ORCID: 0000-0002-4215-7271 and Tagliabue, Alessandro ORCID: 0000-0002-3572-3634
(2021) Impact of intensifying nitrogen limitation on ocean net primary production is fingerprinted by nitrogen isotopes. NATURE COMMUNICATIONS, 12 (1). 6214-.

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Abstract

The open ocean nitrogen cycle is being altered by increases in anthropogenic atmospheric nitrogen deposition and climate change. How the nitrogen cycle responds will determine long-term trends in net primary production (NPP) in the nitrogen-limited low latitude ocean, but is poorly constrained by uncertainty in how the source-sink balance will evolve. Here we show that intensifying nitrogen limitation of phytoplankton, associated with near-term reductions in NPP, causes detectable declines in nitrogen isotopes (δ<sup>15</sup>N) and constitutes the primary perturbation of the 21<sup>st</sup> century nitrogen cycle. Model experiments show that ~75% of the low latitude twilight zone develops anomalously low δ<sup>15</sup>N by 2060, predominantly due to the effects of climate change that alter ocean circulation, with implications for the nitrogen source-sink balance. Our results highlight that δ<sup>15</sup>N changes in the low latitude twilight zone may provide a useful constraint on emerging changes to nitrogen limitation and NPP over the 21<sup>st</sup> century.

Item Type: Article
Uncontrolled Keywords: Phytoplankton, Nitrogen Isotopes, Seawater, Oceans and Seas, Climate Change, Nitrogen Cycle
Divisions: Faculty of Science and Engineering > School of Environmental Sciences
Depositing User: Symplectic Admin
Date Deposited: 02 Nov 2021 16:16
Last Modified: 18 Jan 2023 21:25
DOI: 10.1038/s41467-021-26552-w
Open Access URL: https://doi.org/10.1038/s41467-021-26552-w
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3142541