EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Simulations of atmospheric CO2 and δ13C-CO2 compared to real-time observations at the high altitude station Jungfraujoch

Simone M. Pieber1, Béla Tuzson1, Stephan Henne1, Ute Karstens2, Dominik Brunner1, Martin Steinbacher1, and Lukas Emmenegger1
Simone M. Pieber et al.
  • 1Empa, Laboratory for Air Pollution and Environmental Technology, Duebendorf, Switzerland (
  • 2ICOS Carbon Portal, Lund University, Lund, Sweden

Evaluating atmospheric transport simulations against observations helps refining bottom-up estimates of greenhouse gas fluxes and identifying gaps in our understanding of regional and category-specific contributions to atmospheric mole fractions. This insight is critical in the efforts to mitigate anthropogenic environmental impact. Beside total mole fractions, stable isotope ratios provide further constraints on source-sink processes [1-3].

Here, we present two receptor-oriented model simulations for carbon dioxide (CO2) mole fraction and δ13C-CO2 stable isotope ratios for a nine year period (2009-2017) at the High Altitude Research Station Jungfraujoch (Switzerland, 3580 m asl). The model simulations of CO2 were performed on a 3-hourly time-resolution with two backward Lagrangian particle dispersion models driven by two different numerical weather forecast fields: FLEXPART-COSMO and STILT-ECMWF. Anthropogenic CO2 fluxes were based on the EDGAR v4.3 emissions inventory aggregated into 14 source categories representing fossil and biogenic fuel uses as well as emissions from cement production. Biospheric CO2 fluxes representing the photosynthetic uptake and respiration of 8 plant functional types were based on the Vegetation Photosynthesis and Respiration Model (VPRM). The simulated CO2 emissions per source and sink category were weighted with category-specific δ13C-CO2 signatures from published experimental studies. Background CO2 values at the boundaries of both model domains were taken from global model simulations and the corresponding δ13C-CO2 values were constructed as suggested in Ref. [3]. We compare the simulations to a unique data set of continuous in-situ observations of CO2 mole fractions and δ13C-CO2 stable isotope ratios by quantum cascade laser absorption spectroscopy as described in previous work [1, 4-5], available for the whole nine year period at the site.

The simulated atmospheric CO2 and δ13C-CO2 time-series are in good agreement with the observations and capture the observed variability at the models' 3-hourly time-resolution. This allows for an in-depth evaluation of the contribution of different CO2 emission sources and for an allocation of source regions when Jungfraujoch is influenced by air masses from the planetary boundary layer. In brief, the receptor-oriented model simulations suggest that anthropogenic CO2 contributions are primarily of fossil origin (90%). Anthropogenic emissions contribute between 60% in February, and 20% in July/August, to the CO2 enhancements observed at Jungfraujoch. The remaining fraction is due to biosphere respiration, which thus largely dominates emissions during the summer season. However, intense photosynthetic CO2 uptake during June, July and August roughly outweighs CO2 contributions from anthropogenic activities and biosphere respiration at JFJ.




[1] Tuzson et al., 2011. ACP, 11, 1685

[2] Röckmann et al., 2016. ACP, 16, 10469

[3] Vardag et al., 2016. Biogeosciences, 13, 4237

[4] Tuzson et al., 2008. Appl. Phys. B, 92, 451

[5] Sturm et al., 2013. AMT 6, 1659

How to cite: Pieber, S. M., Tuzson, B., Henne, S., Karstens, U., Brunner, D., Steinbacher, M., and Emmenegger, L.: Simulations of atmospheric CO2 and δ13C-CO2 compared to real-time observations at the high altitude station Jungfraujoch , EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-10588,, 2020


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