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Atmospheric CO2 and δ13C Measurements from 2012 to 2014 at the Environmental Research Station Schneefernerhaus, Germany: Technical Corrections, Temporal Variations and Trajectory Clustering

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DOI: 10.4209/aaqr.2018.01.0010

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Homa Ghasemifard1, Ye Yuan1, Marvin Luepke1, Christian Schunk1, Jia Chen2,3, Ludwig Ries4, Michael Leuchner1, Annette Menzel1,3

  • 1 Professorship of Ecoclimatology, Technische Universität München, 85354 Freising, Germany
  • 2 Professorship of Environmental Sensing and Modeling, Technische Universität München, 80333 Munich, Germany
  • 3 Institute for Advanced Study, Technische Universität München, 85748 Garching, Germany
  • 4 German Environment Agency (UBA), 82475 Zugspitze, Germany


2.5-year dataset of continuous measurements of atmospheric CO2 and δ13C.
Diurnal variations of CO2 and δ13C in different seasons were influenced by PBL.
The arriving air masses at the site were separated into 5 clusters by HYSPLIT model.
Influences of air masses origins on CO2 mixing ratio and δ13C were investigated.
PSCF method was applied to identify source and sink locations.


This study presents continuous atmospheric CO2 and δ13C measurements by wavelength-scanned cavity ring down spectroscopy (Picarro G1101-i) at the high-mountain station Schneefernerhaus, Germany. δ13C values were post-corrected for methane and water spectral interferences using accompanying measurements of CH4, H2O as well as CO2 in dried air, respectively. The best precision of ± 0.2 ‰ for δ13C and ± 4 ppb for CO2 was obtained with an integration time of about 1 hour for δ13C and 2 hours for CO2. The seasonality of CO2 and δ13C was studied by fitting background curves for a complete 2-year period. Peak-to-peak amplitudes of the averaged seasonal cycle were 15.5 ± 0.15 ppm for CO2 and 1.97 ± 0.53 ‰ for δ13C, respectively. Based on the HYSPLIT model, air masses were classified into five clusters, with westerly and northeasterly flows being the most and the least frequent, respectively. In the wintertime, Northwest and Northeast clusters had the higher median level of ΔCO2 and the lower median level Δδ13C (difference between observed and background concentrations), likely caused by anthropogenic emissions. In the summertime, air masses from Northwest had the lowest ΔCO2 and the highest Δδ13C. Potential source contribution functions (PSCF) were used to identify the potential source and sink areas. In winter, source areas for high CO2 mixing ratios (> 75th percentile) were mainly located in northwestern Europe. In summer, areas with high δ13C ratios (> 75th percentile), indicating a carbon sink, were observed in air from Eastern and Central Poland.


CO2 mixing ratio δ13C Mountain station Trajectory HYSPLIT PSCF

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