A flux‐based threshold for anaerobic activity in the ocean
Name
2020GL090423.pdf
Description
Published version
Size
896.46 KB
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Checksum (MD5)
253c3a4900eb965bf8509208e803940f
Author(s)
Zakem, Emily J
Lauderdale, Jonathan
Schlitzer, Reiner
Follows, Michael J
Date Issued
2021
Journal
Geophysical Research Letters
Publisher
American Geophysical Union (AGU)
Version
Final published version
Abstract
© 2021. The Authors. Anaerobic microbial activity in the ocean causes losses of bioavailable nitrogen and emission of nitrous oxide to the atmosphere, but its predictability at global scales remains limited. Resource ratio theory suggests that anaerobic activity becomes sustainable when the ratio of oxygen to organic matter supply is below the ratio required by aerobic metabolisms. Here, we demonstrate the relevance of this framework at the global scale using three-dimensional ocean datasets, providing a new interpretation of existing observations. Evaluations of the location and extent of anoxic zones and a diagnostic rate of pelagic nitrogen loss are consistent with previous estimates. However, we demonstrate that a threshold based on substrate-supply fluxes is qualitatively different from a threshold based solely on the ambient oxygen concentration. This implies that use of the flux-based threshold in global biogeochemical models can result in different predictions of anaerobic activity and nitrogen loss.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1029/2020GL090423
