Nitrous oxide (N2O) is a potent greenhouse gas and an ozone destroying substance. Yet, clear step-by-step protocols to measure N2O transformation rates in freshwater and marine environments are still lacking, challenging inter-comparability efforts. Here we present detailed protocols currently used by leading experts in the field to measure water-column N2O production and consumption rates in both marine and other aquatic environments. We present example 15N-tracer incubation experiments in marine environments as well as templates to calculate both N2O production and consumption rates. We discuss important considerations and recommendations regarding (1) precautions to prevent oxygen (O2) contamination during low-oxygen and anoxic incubations, (2) preferred bottles and stoppers, (3) procedures for 15N-tracer addition, and (4) the choice of a fixative. We finally discuss data reporting and archiving. We expect these protocols will make 15N-labeled N2O transformation rate measurements more accessible to the wider community and facilitate future inter-comparison between different laboratories.
Bibliographical noteFunding Information:
This manuscript is an outcome of the ?Oceanic Methane and Nitrous Oxide Workshop: The present situation and future scenarios!? at Lake Arrowhead in October 2018. We would like to thank all participants for engaging in fruitful and constructive discussions during the workshop. We would also like to thank Colette Kelly, two reviewers and guest associate editor Johannes Karstensen for their constructive comments. Funding. The Lake Arrowhead workshop was organized by the Ocean Carbon and Biogeochemistry project office, which is supported by the US National Science Foundation (NSF, grant #1558412) and the National Aeronautics and Space Administration (grant #NNX17AB17G). This work was funded in part by support from the DOE Great Lakes Bioenergy Research Center (DOE BER Office of Science DE-SC0018409) to NO, NSF grant #1657663 to CF, AJ, and BW, and NSF grant #1927755 to AB.
© Copyright © 2021 Bourbonnais, Frey, Sun, Bristow, Jayakumar, Ostrom, Casciotti and Ward.
- N-tracer incubations
- greenhouse gas
- nitrous oxide