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N2O from the Swiss midlands - regional sources and hot spots - 18 month extension

English title N2O from the Swiss midlands - regional sources and hot spots - 18 month extension
Applicant Mohn Joachim
Number 172585
Funding scheme Project funding
Research institution Luftfremdstoffe / Umwelttechnik 500 - Mobility, Energy and Environment EMPA
Institution of higher education Swiss Federal Laboratories for Materials Science and Technology - EMPA
Main discipline Climatology. Atmospherical Chemistry, Aeronomy
Start/End 01.06.2017 - 30.11.2018
Approved amount 127'647.00
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All Disciplines (3)

Discipline
Climatology. Atmospherical Chemistry, Aeronomy
Geochemistry
Other disciplines of Environmental Sciences

Keywords (5)

greenhouse gas; process based biogeochemical model; stable isotope; nitrous oxide (N2O); Lagrangian particle dispersion model

Lay Summary (German)

Lead
Lachgas (N2O) ist ein wichtiges Treibhausgas und wesentlich am Abbau der stratosphärischen Ozonschicht beteiligt. Seine Konzentration in der Atmosphäre hat in den letzten Jahrzehnten vor allem durch eine vermehrte Freisetzung aus Stickstoff-gedüngten landwirtschaftlichen Böden zugenommen. Für ein besseres Verständnis und eine präzisere Quantifizierung der Lachgasbildung in Böden müssen die beteiligten mikrobiellen Bildungsprozesse identifiziert und deren räumliche sowie zeitliche Variation untersucht werden.
Lay summary

In dem vorliegenden Projekt wird ein neuartiger Ansatz verwendet, um N2O Bildungsprozesse und Quellregionen im Schweizer Mittelland besser verstehen zu können. Hierfür werden einerseits erstmalig kontinuierliche atmosphärische N2O Isotopenmessungen auf einem Messturm (Beromünster) durchgeführt mit deren Hilfe es möglich ist, den Beitrag der verschiedenen mikrobieller Stoffwechselwege (insbesondere Nitrifikation und Denitrifikation) zu bestimmen (WP 1). Andererseits wird ein biogeochemisches Bodenmodell auf der Basis von LandscapeDNDC entwickelt, welches es erlaubt die N2O Freisetzung und deren Isotopenzusammensetzung in der Quellregion des Messturms in einem „bottom up Ansatz“ zu simulieren (WP 2). Anschliessend wird eine Validierung des Bodenmodells mit Hilfe der kontinuierlichen N2O Isotopenmessungen und eines Lagrangen Transportmodells (FLEXPART-COSMO) sowie eines Inversionssystems in einem „top down Ansatz“ durchgeführt (WP 3). Hierbei werden N2O Quellregion, Emissionsstärke und Isotopensignatur bestimmt und mit den Vorhersagen des Bodenmodells verglichen.

Direct link to Lay Summary Last update: 03.07.2017

Responsible applicant and co-applicants

Employees

Project partner

Publications

Publication
Denitrification Is the Main Nitrous Oxide Source Process in Grassland Soils According to Quasi‐Continuous Isotopocule Analysis and Biogeochemical Modeling
Ibraim Erkan, Denk Tobias, Wolf Benjamin, Barthel Matti, Gasche Rainer, Wanek Wolfgang, Zhang Shasha, Kiese Ralf, Butterbach‐Bahl Klaus, Eggleston Sarah, Emmenegger Lukas, Six Johan, Mohn Joachim (2020), Denitrification Is the Main Nitrous Oxide Source Process in Grassland Soils According to Quasi‐Continuous Isotopocule Analysis and Biogeochemical Modeling, in Global Biogeochemical Cycles, 34(6), e2019GB006.
Attribution of N2O sources in a grassland soil with laser spectroscopy based isotopocule analysis
Ibraim Erkan, Wolf Benjamin, Harris Eliza, Gasche Rainer, Wei Jing, Yu Longfei, Kiese Ralf, Eggleston Sarah, Butterbach-Bahl Klaus, Zeeman Matthias, Tuzson Béla, Emmenegger Lukas, Six Johan, Henne Stephan, Mohn Joachim (2019), Attribution of N2O sources in a grassland soil with laser spectroscopy based isotopocule analysis, in Biogeosciences, 16(16), 3247-3266.
Development of a field-deployable method for simultaneous, real-time measurements of the four most abundant N2O isotopocules
Ibraim Erkan, Harris Eliza, Eyer Simon, Tuzson Béla, Emmenegger Lukas, Six Johan, Mohn Joachim (2017), Development of a field-deployable method for simultaneous, real-time measurements of the four most abundant N2O isotopocules, in Isotopes in Environmental and Health Studies, 54(1), 1-15.
Tracking nitrous oxide emission processes at a suburban site with semicontinuous, in situ measurements of isotopic composition suburban N2O isotopic composition
Harris Eliza, Henne Stephan, Hüglin Christoph, Zellweger Christoph, Tuzson Béla, Ibraim Erkan, Emmenegger Lukas, Mohn Joachim (2017), Tracking nitrous oxide emission processes at a suburban site with semicontinuous, in situ measurements of isotopic composition suburban N2O isotopic composition, in Journal of Geophysical Research: Atmospheres, 122(3), 1850-1870.
The nitrogen cycle: A review of isotope effects and isotope modeling approaches
Denk Tobias R.A., Mohn Joachim, Decock Charlotte, Lewicka-Szczebak Dominika, Harris Eliza, Butterbach-Bahl Klaus, Kiese Ralf, Wolf Benjamin (2017), The nitrogen cycle: A review of isotope effects and isotope modeling approaches, in Soil Biology and Biochemistry, 105, 121-137.

Collaboration

Group / person Country
Types of collaboration
Wolfgang Wanek Austria (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
European Geosciences Union General Assembly 2018 Talk given at a conference Disentangling N2O emitting source processes with field-scale online measurements of the four most abundant N2O isotopocules 08.04.2018 Vienna, Austria Ibraim Erkan;
19th WMO/IAEA Meeting on Carbon Dioxide, Other Greenhouse Gases, and Related Measurement Techniques (GGMT-2017) Talk given at a conference Using Isotopic Fingerprints to Trace Nitrous Oxide in the Atmosphere 27.08.2017 Dübendorf, Switzerland Mohn Joachim;
Isotopes The Cross-Disciplinary Conference on Stable Isotope Sciences Talk given at a conference Frontiers in quantum cascade laser based analysis of greenhouse gas stable isotopes 09.07.2017 Ascona, Switzerland Mohn Joachim;


Communication with the public

Communication Title Media Place Year
New media (web, blogs, podcasts, news feeds etc.) First field measurements of laughing gas isotopes Empa news portal International 2019
Media relations: print media, online media New technique could help scientists track nitrous oxide sources Earth & Space Science News International 2017

Associated projects

Number Title Start Funding scheme
163075 Assessment of the global N2O budget based on seasonal and long-term isotope measurements at Jungfraujoch and the Cape Grim Air Archive 01.12.2016 Project funding
166255 Clumped isotopes as a novel tracer for the N2O cycle 01.09.2016 Project funding
134611 Entwicklung eines Quantenkaskadenlaser Spektrometers zur kontinuierlichen Bestimmung von Methan Isotopen 01.01.2012 Project funding
150237 N2O from the Swiss midlands - regional sources and hot spots 01.06.2014 Project funding

Abstract

Nitrous oxide (N2O) is a potent greenhouse gas (GHG) and an important anthropogenic contributor to stratospheric ozone-depletion. Its atmospheric abundance increased significantly in recent decades due to the perturbation of the nitrogen cycle, mainly due to growing usage of mineral fertilizers and enhanced microbial production in soils. Process-oriented biogeochemical soil models are increasingly used to assess regional scale N2O budgets and to develop mitigation strategies. However, the validation strategies usually aim to minimize the uncertainty for total N2O emissions at site scale and, thus, the partitioning between specific microbial processes and the reliability of budgets at larger scales remains unclear. Microbial source processes of N2O, specifically nitrification and/ or denitrification, exhibit characteristic isotopic signatures that can be used to quantify individual N2O sources. However, these measurements have been scarce and limited to low-frequency flask sampling in combination with laboratory-based mass spectrometric analysis.The SNF - DFG Lead Agency project “N2O from the Swiss midlands: regional sources and hot spots”, initiated in 2014, aims to combine two complementary approaches: real-time top-down measurements of N2O concentrations with site-specific isotopic composition at heights of 12 m or lower (i.e., the atmospheric surface layer) and 212 m (i.e., the atmospheric boundary layer), and bottom-up biogeochemical modelling (LandscapeDNDC). During the first two years of the project, the following milestones have been successfully accomplished for the individual work packages:WP1 (Empa):- Development and validation of a measurement technique for N2O isotopologues with target precision of 0.1 ‰ for d15Na, d15Nb and d18O-N2O completed [E. Ibraim et al., IEHS, 2017].- Advancement of N2O isotopic analysis accuracy achieved by expanding the calibration scale to d18O-N2O.- Preparatory work at the Beromünster tall tower station (e.g., air conditioning) completed and first N2O concentration measurements executed.WP2 (KIT):- Review of N isotope effects published [T. Denk et al., SBB, 2017](KIT, Empa)- Based on the review, development and implementation of the isotope sub-module SIMONE into LandscapeDNDC and validation on available data at site scale (Chamau). WP3 (Empa): - High-resolution simulation (FLEXPART-COSMO1) of one-year footprint climatology for the Beromünster catchment to provide guidance for soil sampling strategy.- Simulations of atmospheric N2O concentrations and isotopic composition for a suburban site [E. Harris et al., JGR, 2017].In the presented 18 month extension project we will carry out one additional extended field campaign at site scale combining atmospheric measurements with simultaneous automatic and manual chamber measurements at adjacent grassland, arable and forest sites to enable a broader model validation of LandscapeDNDC/SIMONE. Finally, the previously envisaged observations at different inlet heights at the Beromünster tall tower and their combination with atmospheric transport simulations to derive regional scale emissions will be carried out. This work will be conducted by two PhD students at Empa and KIT.
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