Articles | Volume 19, issue 10
https://doi.org/10.5194/amt-19-3557-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-19-3557-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Correction and calibration protocol for isotope data via CRDS: a study case for N2O and other isotope systems
Julius C. Havsteen
CORRESPONDING AUTHOR
Empa, Laboratory for Air Pollution/Environmental Technology, Dübendorf, Switzerland
Mehr Fatima
VTT Technical Research Centre of Finland Ltd, Espoo, Finland
Simone Brunamonti
Empa, Laboratory for Air Pollution/Environmental Technology, Dübendorf, Switzerland
Andrea Pogány
Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
Thomas Hausmaninger
VTT Technical Research Centre of Finland Ltd, Espoo, Finland
Benjamin Wolf
Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research, Atmospheric Environmental Research (IMK-IFU), Garmisch-Partenkirchen, Germany
Reinhard Well
Thünen Institute of Climate-Smart Agriculture, Braunschweig, Germany
Empa, Laboratory for Air Pollution/Environmental Technology, Dübendorf, Switzerland
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Noémy Chénier, Paul M. Magyar, Jakob Zopfi, Claudia Frey, Thomas Kuhn, Moritz F. Lehmann, and Joachim Mohn
EGUsphere, https://doi.org/10.5194/egusphere-2026-1824, https://doi.org/10.5194/egusphere-2026-1824, 2026
This preprint is open for discussion and under review for Biogeosciences (BG).
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N₂O is a greenhouse gas produced by microbes during nitrogen cycling. We studied two bacterial species and found that the isotope signatures of the N₂O they produced changed strongly depending on growth conditions and cell activity. Early during growth, the distribution of N isotopes within the N₂O molecule also changed unexpectedly. These results show that N₂O isotope signatures are more variable than previously assumed and depend strongly on physiology.
Paul M. Magyar, Nico Kueter, Simone Brunamonti, Naizhong Zhang, Ivan Prokhorov, Noémy Chénier, Lukas Emmenegger, Béla Tuzson, and Joachim Mohn
EGUsphere, https://doi.org/10.5194/egusphere-2026-874, https://doi.org/10.5194/egusphere-2026-874, 2026
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
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Human activity drives increases in atmospheric nitrous oxide. Stable isotopes help trace the pathways involved. We developed a reliable way to calibrate measurements of rare isotopic variants of nitrous oxide so results from different labs can be compared. By heating nitrous oxide with a catalyst, the molecules reach well-defined equilibrium patterns suitable as a reference. To measure these isotopic variants quickly and precisely, we improved a laser-based measurement approach.
Hannes Keck, Laurence Strubbe, Paul M. Magyar, Adriano Joss, Andreas Froemelt, André Kupferschmid, Klaus-Holger Knorr, and Joachim Mohn
EGUsphere, https://doi.org/10.5194/egusphere-2026-857, https://doi.org/10.5194/egusphere-2026-857, 2026
This preprint is open for discussion and under review for Atmospheric Measurement Techniques (AMT).
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We monitored nitrous oxide in a pilot wastewater treatment plant in real time to understand how microbes produce and remove this greenhouse gas. We designed and tested a laser-based analytical setup, with which we were able to show that denitrification is the main source of nitrous oxide emissions and that low oxygen concentrations enhances nitrous oxide removal. Our approach offers a new way to monitor the wastewater treatment processes and to cut climate-relevant nitrous oxide emissions.
Samin Payrosangari, Kathrin Fuchs, Benjamin Wolf, Ralf Kiese, and Clemens Scheer
EGUsphere, https://doi.org/10.5194/egusphere-2025-5155, https://doi.org/10.5194/egusphere-2025-5155, 2025
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In our manuscript, we implement a machine learning based model to improve the simulation of daily N2O emissions at regional scale across several pre-alpine grasslands in Central Europe. The study focuses on evaluating the model’s general applicability to other grasslands in the region. This work contributes to the development of generic N₂O emission models, thereby reducing the effort required to estimate emissions from sites lacking direct measurements.
Simone Brunamonti, Harald Saathoff, Albert Hertzog, Glenn Diskin, Masatomo Fujiwara, Karen Rosenlof, Ottmar Möhler, Béla Tuzson, Lukas Emmenegger, Nadir Amarouche, Georges Durry, Fabien Frérot, Jean-Christophe Samake, Claire Cenac, Julio Lopez, Paul Monnier, and Mélanie Ghysels
Atmos. Meas. Tech., 18, 5321–5348, https://doi.org/10.5194/amt-18-5321-2025, https://doi.org/10.5194/amt-18-5321-2025, 2025
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Water vapor is a strong greenhouse gas, and accurate measurements of its concentration in the upper atmosphere (~8–25 km altitude) are crucial for reliable climate predictions. We investigated the performance of four airborne hygrometers, deployed on aircraft or stratospheric balloon platforms and based on different techniques, in a climate simulation chamber. The results demonstrate the high accuracy and reliability of the involved sensors for atmospheric monitoring and research applications.
Sushmita Deb, Mikk Espenberg, Reinhard Well, Michał Bucha, Marta Jakubiak, Ülo Mander, Mariusz-Orion Jędrysek, and Dominika Lewicka-Szczebak
Biogeosciences, 22, 5535–5556, https://doi.org/10.5194/bg-22-5535-2025, https://doi.org/10.5194/bg-22-5535-2025, 2025
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This study investigates nitrogen cycling in groundwater from an agricultural area using organic fertilizer. The research combines isotope and microbial studies to track transformations. High-nitrate samples were incubated with a low addition of 15N tracer. Results showed a shift from archaeal nitrification to bacterial denitrification under low oxygen with glucose, confirmed by isotope and microbial analyses. The findings offer insights for improving water quality and pollution management.
Fawad Khan, Samuel Franco Luesma, Frederik Hartmann, Michael Dannenmann, Rainer Gasche, Clemens Scheer, Andreas Gattinger, Wiebke Niether, Elizabeth Gachibu Wangari, Ricky Mwangada Mwanake, Ralf Kiese, and Benjamin Wolf
Biogeosciences, 22, 5081–5102, https://doi.org/10.5194/bg-22-5081-2025, https://doi.org/10.5194/bg-22-5081-2025, 2025
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Crop rotations with legumes and use of organic and mineral fertilizers show potential to reduce agricultural N losses. This study examined N losses, including direct N2 flux, on two adjacent sites with different management histories: organic farming (OF) with legume cultivation and integrated farming (IF) using synthetic and organic N inputs. IF increased soil organic carbon and nitrogen content and 15N recovery and showed a balanced N budget (i.e. more efficient N cycling compared to OF).
Samuel Franco-Luesma, María Alonso-Ayuso, Benjamin Wolf, Borja Latorre, and Jorge Álvaro-Fuentes
SOIL, 11, 523–533, https://doi.org/10.5194/soil-11-523-2025, https://doi.org/10.5194/soil-11-523-2025, 2025
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Agriculture may play a significant role in climate change mitigation. For this reason, it is necessary to have good estimations of the greenhouse gas (GHG) emissions from agricultural activities. In this work, two different chamber systems to determine GHGs were compared. Our results highlighted that automated chamber systems, compared to manual chamber systems, are a powerful tool for quantifying GHG fluxes, allowing us to capture the large temporal variability that characterizes them.
Roxanne Daelman, Marijn Bauters, Matti Barthel, Emmanuel Bulonza, Lodewijk Lefevre, José Mbifo, Johan Six, Klaus Butterbach-Bahl, Benjamin Wolf, Ralf Kiese, and Pascal Boeckx
Biogeosciences, 22, 1529–1542, https://doi.org/10.5194/bg-22-1529-2025, https://doi.org/10.5194/bg-22-1529-2025, 2025
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The increase in atmospheric concentrations of several greenhouse gases (GHGs) since 1750 is attributed to human activity. However, natural ecosystems, such as tropical forests, also contribute to GHG budgets. The Congo Basin hosts the second largest tropical forest and is understudied. In this study, measurements of soil GHG exchange were carried out during 16 months in a tropical forest in the Congo Basin. Overall, the soil acted as a major source of CO2 and N2O and a minor sink of CH4.
Simone Brunamonti, Manuel Graf, Tobias Bühlmann, Céline Pascale, Ivan Ilak, Lukas Emmenegger, and Béla Tuzson
Atmos. Meas. Tech., 16, 4391–4407, https://doi.org/10.5194/amt-16-4391-2023, https://doi.org/10.5194/amt-16-4391-2023, 2023
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The abundance of water vapor (H2O) in the upper atmosphere has a significant impact on the rate of global warming. We developed a new lightweight spectrometer (ALBATROSS) for H2O measurements aboard meteorological balloons. Here, we assess the accuracy and precision of ALBATROSS using metrology-grade reference gases. The results demonstrate the exceptional potential of mid-infrared laser absorption spectroscopy as a new reference method for in situ measurements of H2O in the upper atmosphere.
Marsailidh M. Twigg, Augustinus J. C. Berkhout, Nicholas Cowan, Sabine Crunaire, Enrico Dammers, Volker Ebert, Vincent Gaudion, Marty Haaima, Christoph Häni, Lewis John, Matthew R. Jones, Bjorn Kamps, John Kentisbeer, Thomas Kupper, Sarah R. Leeson, Daiana Leuenberger, Nils O. B. Lüttschwager, Ulla Makkonen, Nicholas A. Martin, David Missler, Duncan Mounsor, Albrecht Neftel, Chad Nelson, Eiko Nemitz, Rutger Oudwater, Celine Pascale, Jean-Eudes Petit, Andrea Pogany, Nathalie Redon, Jörg Sintermann, Amy Stephens, Mark A. Sutton, Yuk S. Tang, Rens Zijlmans, Christine F. Braban, and Bernhard Niederhauser
Atmos. Meas. Tech., 15, 6755–6787, https://doi.org/10.5194/amt-15-6755-2022, https://doi.org/10.5194/amt-15-6755-2022, 2022
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Ammonia (NH3) gas in the atmosphere impacts the environment, human health, and, indirectly, climate. Historic NH3 monitoring was labour intensive, and the instruments were complicated. Over the last decade, there has been a rapid technology development, including “plug-and-play” instruments. This study is an extensive field comparison of the currently available technologies and provides evidence that for routine monitoring, standard operating protocols are required for datasets to be comparable.
Clare E. Singer, Benjamin W. Clouser, Sergey M. Khaykin, Martina Krämer, Francesco Cairo, Thomas Peter, Alexey Lykov, Christian Rolf, Nicole Spelten, Armin Afchine, Simone Brunamonti, and Elisabeth J. Moyer
Atmos. Meas. Tech., 15, 4767–4783, https://doi.org/10.5194/amt-15-4767-2022, https://doi.org/10.5194/amt-15-4767-2022, 2022
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In situ measurements of water vapor in the upper troposphere are necessary to study cloud formation and hydration of the stratosphere but challenging due to cold–dry conditions. We compare measurements from three water vapor instruments from the StratoClim campaign in 2017. In clear sky (clouds), point-by-point differences were <1.5±8 % (<1±8 %). This excellent agreement allows detection of fine-scale structures required to understand the impact of convection on stratospheric water vapor.
Balázs Grosz, Reinhard Well, Rene Dechow, Jan Reent Köster, Mohammad Ibrahim Khalil, Simone Merl, Andreas Rode, Bianca Ziehmer, Amanda Matson, and Hongxing He
Biogeosciences, 18, 5681–5697, https://doi.org/10.5194/bg-18-5681-2021, https://doi.org/10.5194/bg-18-5681-2021, 2021
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To assure quality predictions biogeochemical models must be current. We use data measured using novel incubation methods to test the denitrification sub-modules of three models. We aim to identify limitations in the denitrification modeling to inform next steps for development. Several areas are identified, most urgently improved denitrification control parameters and further testing with high-temporal-resolution datasets. Addressing these would significantly improve denitrification modeling.
Lena Rohe, Traute-Heidi Anderson, Heinz Flessa, Anette Goeske, Dominika Lewicka-Szczebak, Nicole Wrage-Mönnig, and Reinhard Well
Biogeosciences, 18, 4629–4650, https://doi.org/10.5194/bg-18-4629-2021, https://doi.org/10.5194/bg-18-4629-2021, 2021
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This is the first experimental setup combining a complex set of methods (microbial inhibitors and isotopic approaches) to differentiate between N2O produced by fungi or bacteria during denitrification in three soils. Quantifying the fungal fraction with inhibitors was not successful due to large amounts of uninhibited N2O production. All successful methods suggested a small or missing fungal contribution. Artefacts occurring with microbial inhibition to determine N2O fluxes are discussed.
Ruth E. Hill-Pearce, Aimee Hillier, Eric Mussell Webber, Kanokrat Charoenpornpukdee, Simon O'Doherty, Joachim Mohn, Christoph Zellweger, David R. Worton, and Paul J. Brewer
Atmos. Meas. Tech., 14, 5447–5458, https://doi.org/10.5194/amt-14-5447-2021, https://doi.org/10.5194/amt-14-5447-2021, 2021
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There is currently a need for gas reference materials with well-characterised delta values for monitoring N2O amount fractions. We present work towards the preparation of gas reference materials for calibration of in-field monitoring equipment, which target the WMO-GAW data quality objectives for comparability of amount fraction and demonstrate the stability of δ15Nα, δ15Nβ and δ18O values with pressure and effects of cylinder passivation.
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Short summary
We present a new correction and calibration protocol to improve the accuracy of nitrous oxide isotope measurements obtained using laser spectroscopy. Through laboratory experiments, spectral simulations, and an automated MATLAB (Matrix Laboratory) reduction scheme, we identify and correct biases caused by matrix gas composition, spectral interferences and instrument variability. This protocol enables researchers to produce more reliable isotope data and supports standardised isotope analyses across laboratories.
We present a new correction and calibration protocol to improve the accuracy of nitrous oxide...