Related Experiment Video
Updated: May 23, 2026
05:04
Visualization of Productivity Zones Based on Nitrogen Mass Balance Model in Narragansett Bay, Rhode Island
Published on: July 14, 2023
Global oceanic production of nitrous oxide
Alina Freing1, Douglas W R Wallace, Hermann W Bange
1GEOMAR/Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
Summary
Oceanic nitrous oxide (N2O) production is primarily driven by nitrification, not denitrification, with global subsurface N2O production estimated between 3.1-3.4 Tg N yr(-1). This finding revises previous estimates of N2O sources in marine environments.
Area of Science:
- Oceanography
- Biogeochemistry
- Environmental Science
Background:
- Nitrous oxide (N2O) is a potent greenhouse gas with significant oceanic sources.
- Accurate estimation of oceanic N2O production is crucial for global climate modeling.
- Previous studies may have overestimated the contribution of denitrification to oceanic N2O production.
Purpose of the Study:
- To estimate global oceanic N2O production rates and concentrations.
- To differentiate between nitrification and denitrification as N2O production pathways.
- To assess the impact of environmental changes on future oceanic N2O sources.
Main Methods:
- Utilized transient time distributions from tracer data.
- Integrated in situ measurements of N2O.
- Modeled N2O production and decomposition mechanisms along water mass transport paths.
Main Results:
- Oceanic N2O production is dominated by nitrification (approx. 93%), with denitrification contributing only about 7%.
- Global annual subsurface N2O production is estimated at 3.1 ± 0.9 to 3.4 ± 0.9 Tg N yr(-1).
- The majority of subsurface N2O is produced in the upper 500 meters of the water column.
Conclusions:
- Nitrification is the primary driver of oceanic N2O production, contrary to previous assumptions.
- The estimated production aligns with global N2O emissions, suggesting mixed layer sources are unlikely.
- Ongoing ocean changes like deoxygenation and warming may alter future oceanic N2O production.
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