Project

Discipline

mass independent fractionation; Jungfraujoch; Carbon cycle; water isotopes; Stratospheric Tropospheric Exchange; Carbon Dioxide; Water cycle

Lead
Die IPCC Arbeitsgruppe I hat am 22. September 2013 die Zusammenfassung für Politiker publiziert. Darin ist unmissverständlich die dominante Rolle des CO2 als Treiber des Klimawandels beschrieben. Daraus ergibt sich für die Forschergemeinschaft, dass die biogeochemischen Kreisläufe weiter intensive beobachtet werden müssen. Diese Beobachtungen schliessen die Messung der relevanten Treibhausgas-Konzentrationen, deren zeitlicher und örtlicher Verteilung als auch deren Emissionen. Das Zusammenspiel solch erstellter Messreihen mit Erdsystemmodellen führt zu einem verbesserten Verständnis der zugrundeliegenden Prozesse und erlaubt dadurch Auswirkungen auf natürliche Ressourcen, auf die Wirtschaft und Gesellschaft zu erkennen.
Lay summary
Die längste CO2 Zeitreihe der Schweiz wurde erst im Jahre 2000 initiiert, seit Ende 2004 in kontinuierlicher Form. Diese Zeitreihe wurde ergänzt durch Messungen assozierter Parameters wie (i) kontinuierliche O2 Messungen und (ii) diskrete Flaschenprobenahme für Ar/N2 und Isotopenbestimmungen an CO2 und den Hauptluftkomponenten. Der Fokus des vorliegenden Projekts - neben der Interpretation des gesamten Palette von Parameter - wird auf die Dreifach-Sauerstoffisotope gelegt. Namentlich d17O, d18O und D17O des atmosphärischen Sauerstoffs als auch des troposphärischen und stratosphärischen Wasserdampfes. Vorläufige Messungen im Labor in Bern haben interessante D17O Veränderungen gezeigt. Die Dreifach-Sauerstoffisotopen-Methode erlaubt uns die biogeochemischen Prozesse als auch die Gasaustauschflüsse zwischen der Troposphäre und der Stratosphäre zu untersuchen.

Direct link to Lay Summary

Last update: 21.05.2014

Lead
With the release of the Summary for Policymakers of the IPCC Working Group I on September 27, 2013 the role of carbon dioxide (CO2) as the main actor in climate change is further strengthened. It explicitly states:“Total radiative forcing is positive, and has led to an uptake of energy by the climate system. The largest contribution to total radiative forcing is caused by the increase in the atmospheric concentration of CO2 since 1750.”The task for the research community therefore is to further investigate the biogeochemical cycles, i.e. monitoring the concentrations of relevant greenhouse gases, quantifying their temporal and spatial emissions, improving Earth system models in order to understand the underlying processes and to assess the climate change impacts on natural resources, economy and society. This and the previous projects aimed at establishing the longest CO2 record in Switzerland, namely at Jungfraujoch.
Lay summary
The longest CO2 record in Switzerland has only started in late 2000, since the end of 2004 in a continuous manner. This record was complemented by associated parameters such as (i) continuous O2 measurements and (ii) discrete flask sampling for Ar/N2 and isotope compositions on CO2 and the main air components. The focus of the upcoming project period – besides the common interpretation of the full suite atmospheric measurements – will be on specific (triple) isotope ratio measurements, namely d17O, d18O, and D17O of atmospheric molecular oxygen (O2) and both tropospheric and stratospheric water vapour (H2O). Preliminary measurements done at our laboratory have revealed interesting variations in D17O. Triple isotopic composition of oxygen allows us to investigate biogeochemical processes as well as gas exchange fluxes between the upper troposphere and lower stratosphere.

Direct link to Lay Summary

Last update: 21.05.2014

Communication	Title	Media	Place	Year

Number	Title	Start	Funding scheme

With the release of the Summary for Policymakers of the IPCC Working Group I on September 27, 2013 the role of carbon dioxide (CO2) as the main actor in climate change is further strengthened. It explicitly states:“Total radiative forcing is positive, and has led to an uptake of energy by the climate system. The largest contribution to total radiative forcing is caused by the increase in the atmospheric concentration of CO2 since 1750.”Thomas Stocker, the other Co-Chair of Working Group I said: "Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions."The task for the research community therefore is to further investigate the biogeochemical cycles, i.e. monitoring the concentrations of relevant greenhouse gases, quantifying their temporal and spatial emissions, improving Earth system models in order to understand the underlying processes and to assess the climate change impacts on natural resources, economy and society. The contribution of this proposal is focussing on atmospheric processes, i.e. A) Measurements of carbon dioxide and associated tracers and B) Tracing Stratosphere Troposphere Exchange (STE) by water isotope measurements. The longest CO2 record in Switzerland has only started in late 2000, since the end of 2004 in a continuous manner. This record was complemented by associated parameters such as (i) continuous O2 measurements and (ii) discrete flask sampling for Ar/N2 and isotope compositions on CO2 and the main air components. The focus of the upcoming project period - besides the common interpretation of the full suite atmospheric measurements - will be on specific (triple) isotope ratio measurements, namely?d17O, d18O, and D17O of atmospheric molecular oxygen (O2) and both tropospheric and stratospheric water vapour (H2O). Preliminary measurements done at our laboratory have revealed interesting variations in D17O. Questions related to D17O of atmospheric molecular oxygen (O2) are: Are the observed deviations to lower values in D17O (O2) robust? Is the hypothesis that these deviations are linked to the terrestrial biosphere activity modulated by meteorological conditions correct? Do we find independent supportive information for this hypothesis? Is this signal due to a lowering of the photosynthetic or an increase in respiration activity? Shouldn’t we also observe a correspondent decrease in d17O and d18O (lower respiration) of molecular oxygen?Questions related to D17O of atmospheric water vapour (H2O) are: Can we reproduce the D17O changes observed in water samples from 1991/1992 (Pinatubo eruptions) and 2003 (European heat wave)? Are they seen throughout the Swiss precipitation network? Do water vapour measurements of stratospheric origin at Jungfraujoch exhibit a different D17O value compared to tropospheric water vapour generally observed there? If yes, how large are the differences in the values? Are they related to isotope anomalies in molecular oxygen or O2/N2 ratios?Both topics naturally extend the paleoclimate related research performed at the Climate and Environmental Physics Division. The first topic allows us to compare today's atmospheric CO2 variations from a unique observational site with those reconstructed from ice cores, and the second topic is closely linked to our long-term involvement in water cycle research.This proposal seeks financial support for part of the research done at Jungfraujoch by the group of Prof. Leuenberger from the Division of Climate and Environmental Physics. The monitoring of CO2 and O2 concentrations at Jungfraujoch is not part of this budget since long term financial support was granted to the Swiss ICOS activities (project related to ESFRI and “Schweizer Roadmap für Forschungsinfrastrukturen”) through the SNF and ETH.