isotopologues; Jungfraujoch; global budget; Cape Grim Air Archive; nitrous oxide
Mohn Joachim, Biasi Christina, Bodé Samuel, Boeckx Pascal, Brewer Paul J., Eggleston Sarah, Geilmann Heike, Guillevic Myriam, Kaiser Jan, Kantnerová Kristýna, Moossen Heiko, Müller Joanna, Nakagawa Mayuko, Pearce Ruth, Rein Isabell, Steger David, Toyoda Sakae, Wanek Wolfgang, Wexler Sarah K., Yoshida Naohiro, Yu Longfei (2022), Isotopically characterised N2O reference materials for use as community standards, in Rapid Communications in Mass Spectrometry
, 36(13), e9296.
Yu Longfei, Harris Eliza, Lewicka‐Szczebak Dominika, Barthel Matti, Blomberg Margareta R.A., Harris Stephen J., Johnson Matthew S., Lehmann Moritz F., Liisberg Jesper, Müller Christoph, Ostrom Nathaniel E., Six Johan, Toyoda Sakae, Yoshida Naohiro, Mohn Joachim (2020), What can we learn from N2O isotope data? – Analytics, processes and modelling, in Rapid Communications in Mass Spectrometry
, 34(20), e8858.
Yu Longfei, Harris Eliza, Henne Stephan, Eggleston Sarah, Steinbacher Martin, Emmenegger Lukas, Zellweger Christoph, Mohn Joachim (2020), The isotopic composition of atmospheric nitrous oxide observed at the high-altitude research station Jungfraujoch, Switzerland, in Atmospheric Chemistry and Physics
, 20(11), 6495-6519.
Harris Stephen J., Liisberg Jesper, Xia Longlong, Wei Jing, Zeyer Kerstin, Yu Longfei, Barthel Matti, Wolf Benjamin, Kelly Bryce F. J., Cendón Dioni I., Blunier Thomas, Six Johan, Mohn Joachim (2020), N2O isotopocule measurements using laser spectroscopy: analyzer characterization and intercomparison, in Atmospheric Measurement Techniques
, 13(5), 2797-2831.
N2O is a strong greenhouse gas and an important ozone depleting substance released from a range of natural sources and anthropogenic activities. Anthropogenic sources of N2O are dominated by disperse and highly variable agricultural soil emissions, which, combined with the long lifetime of N2O, makes source apportionment and thus mitigation challenging. Although the total global source and sink strengths for N2O are relatively well constrained, individual source contributions and, in particular, the factors causing seasonality and interannual variability in N2O mixing ratio and growth rate are poorly known. Measurement and model studies suggest source variability is the dominant factor causing variations in N2O mixing ratios on an interannual scale, rather than changing strength of stratosphere troposphere exchange. Isotope measurements combined with modelling show great potential to unravel sources, however currently N2O isotope measurements with the required spatial and temporal coverage and precision are not available.The aim of this study is to assess the global N2O budget by providing for the first time high precision data (d15Na, d15Nb, d18O: <0.1‰) showing seasonal and interannual changes in the site-specific N2O isotopic composition, in combination with a modelling approach for data interpretation. We propose to measure long-term trends and interannual variability using 30 years of archived air samples from the Cape Grim Air Archive, Australia. In addition, seasonal and intra-annual variability will be examined at higher temporal resolution over two years based on flask sampling at remote measuring stations in the southern (Cape Grim, monthly sampling) and northern (Jungfraujoch, weekly sampling) hemispheres. Concentration and isotopic composition analyses for all samples will be carefully calibrated to ensure traceability and comparability with other studies into the future. The isotopic data will be interpreted using various box modelling approaches to identify in particular changes in the isotopic signature of the anthropogenic source, as well as variations in sources and sinks responsible for seasonality and interannual variability. These results will be used to address three major research questions:• Has the global anthropogenic source isotopic signature changed over the past 30 years? How does this reflect changes in source identity and climate?• What is the difference in N2O isotopic composition between the northern and southern hemispheres, in particular isotopic site preference? Does this agree with expectations based on hemispheric source estimates?• What can isotopic composition changes tell us about the major drivers of seasonality and interannual variability in N2O mixing ratio and growth rate?This study will improve our understanding of the global N2O cycle, facilitating the development of models to predict changes in N2O emissions in response to climate and societal changes in the coming decades. These results will aid in the development of targeted mitigation policies to reduce future N2O emissions.