Sunlight drives the abiotic formation of nitrous oxide in fresh and marine waters.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40080575.
- Also identified by DOI 10.1126/science.adq0302.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
Nitrous oxide (N<sub>2</sub>O) is a potent greenhouse gas and the main stratospheric ozone-depleting agent, yet its sources are not well resolved. In this work, we experimentally show a N<sub>2</sub>O production pathway not previously considered in greenhouse gas budgets, which we name photochemodenitrification. Sunlight induces substantial and consistent N<sub>2</sub>O production under oxic abiotic conditions in fresh and marine waters. We measured photochemical N<sub>2</sub>O production rates using isotope tracers and determined that nitrite is the main substrate and that nitrate can also contribute after being photoreduced to nitrite. Additionally, this N<sub>2</sub>O production was strongly correlated to the radiation dose. Photochemodenitrification exceeded biological N<sub>2</sub>O production in surface waters. Although previously overlooked, this process may contribute considerably to global N<sub>2</sub>O emissions through its occurrence in fresh and marine surface waters.