New stable isotope methods for tracking nitrous oxide sources

Nitrous oxide (N2O) is a molecule produced by both aerobic and anaerobic processes in the biological nitrogen cycle. It is also a greenhouse gas and source of ozone-depleting N-oxides that is accumulating in the atmosphere. Anything that can be learned about its sources in the environment is valuable both for mitigating its impacts and for providing clues into the processes at work in the biogeochemical cycling of nitrogen. We have developed novel mass spectrometry techniques to measure six distinct isotopic properties of nitrous oxide, including four measurements that have previously been used to characterize the biological nitrogen cycle and two new measurements, of the isotopologues 14N15N18O and 15N14N18O. These measurements provide improved constraints on biogenic sources of N2O. We are now using this technique to characterize N2O from a number of biological and environmental sources, including bacterial and fungal denitrification and bacterial ammonia oxidation. The information provided by all six isotopologues provides insights into the mechanisms of these processes

Associated Personnel

Paul Magyar


John Eiler (Caltech)