Nitrous oxide (N2O) is a potent greenhouse gas and the main agent depleting stratospheric ozone. During the last decade, its atmospheric levels have risen faster than previously estimated, highlighting the need to better understand its sources. While microbial processes like ammonia oxidation and denitrification are known contributors, our recent research has uncovered a novel abiotic pathway—photochemodenitrification—where sunlight drives N2O production from nitrite in oxygen-rich surface fresh and marine waters. In addition, photochemodenitrification exceeded biological N₂O production in surface waters. Our latest findings reveal that this photochemical process also occurs in polar regions and the tropical open ocean, emphasizing its global distribution. Because it occurs in surface waters in direct contact with the atmosphere, photochemodenitrification holds the potential to contribute significantly to N2O emissions.

*Refreshments: 10:30 AM - 11:00 AM (Atrium)