Atmospheric Carbon Dioxide Record from Garmisch-Partenkirchen
R. Sladkovic, H.E. Scheel, W. Seiler
Fraunhofer Institute for Atmospheric Environmental Research (IFU),
Period of Record
Ambient air has been measured continuously using a URAS 2T nondispersive infrared (NDIR) analyzer with a flowing reference gas. Every 24 hours, two CO2-in-N2 working standards are passed into the instrument for calibration. The water vapor content of both the ambient air and the calibration gases is conditioned to a dew point of about 1°C. The mixing ratios of the working standards are related to two primary CO2-in-N2 standards (312 and 387 ppmv) based on the 1974 Keeling scale (WMO X74 scale), which are kept in the laboratory. Details on the measurements through 1985 are given by Reiter et al. (1986). In 1987, the sampling site was displaced horizontally by about 0.5 km. Whereas the sample air intake was 10 m above ground at the former site, it is 5 m above ground at the current site.
47°28' N, 11°03' E
The monitoring site is located outside Garmisch-Partenkirchen on the grass-covered floor of the valley. The measurements performed at Garmisch-Partenkirchen are complemented by measurements at the nearby stations Wank Peak (1776 m above MSL) and Zugspitze (2937 m above MSL). Because of strong local influence (vegetation and meteorology), the CO2 concentrations at Garmisch-Partenkirchen are higher and show greater seasonal amplitudes than the concentrations measured at Wank or Zugspitze. Previously reported monthly mean CO2 concentrations for Garmisch-Partenkirchen (cf. Trends '91) were based on valid data (only technically invalid data had been eliminated). In contrast, the monthly values given here were calculated from day-time measurements only, because they are less biased by local influence. Moreover, the raw data were filtered visually with respect to obviously local or synoptic processes (such as vertical exchange or frontal passages, respectively). This procedure has yielded annual concentrations for Garmisch-Partenkirchen which are lower by 6.8 to 12.2 parts per million by volume (ppmv) than the previously reported values. A change of sampling conditions due to the transfer of the station cannot be completely ruled out; therefore, the time series obtained before 1987 and that obtained thereafter should be regarded separately.
According to the filtered data, the annual atmospheric CO2 concentrations at Garmisch-Partenkirchen increased from 330.2 ppmv in 1978 to 345.1 ppmv in 1986 and from 347.6 ppmv in 1988 to 354.7 ppmv in 1992. Annual growth rates varied more strongly during the first period than during the second.
- Reiter, R., and H.J. Kanter. 1980. First results of simultaneous recordings of the CO2-concentration from a valley station and a neighboring mountain station at an altitude difference of about 1 km. Archiv fuer Meteorologie, Geophysik, und Bioklimatologie 28:1-13.
- Reiter, R., and H.J. Kanter. 1982. Time behavior of CO2 and O3 in the lower troposphere based on recordings from neighboring mountain stations between 0.7 and 3.0 km ASL including the effects of meteorological parameters. Archiv fuer Meteorologie, Geophysik, und Bioklimatologie 30:191-225.
- Reiter, R., K. Munzert, and H.J. Kanter. 1985. Parameterization of the variation of CO2 and O3 in the lower troposphere based on 5-year recordings at 0.7/1.8/3.0 km ASL with consideration of the most important magnitudes of meteorology, biomass, and anthropogenic effects. World Meteorological Organization, Special Environmental Report No. 16. WMO No. 647. TECOMAC. Geneva.
- Reiter, R., R. Sladkovic, and H.J. Kanter. 1986. Concentration of trace gases in the lower troposphere, Part I: Carbon dioxide. Meteorology and Atmospheric Physics 35:187-200.
- World Meteorological Organization (WMO). 1989. Provisional daily atmospheric carbon dioxide concentrations as measured at BAPMoN sites for the years 1986 and 1987. WMO/TD-No. 306. World Meteorological Organization, Geneva.
- World Meteorological Organization (WMO). 1990. Provisional daily atmospheric carbon dioxide concentrations as measured at BAPMoN sites for the year 1988. WMO/TD-No. 355. World Meteorological Organization, Geneva.
- World Meteorological Organization (WMO). 1991. Provisional daily atmospheric carbon dioxide concentrations as measured at (GAW)-BAPMoN sites for the year 1990. WMO/TD-No. 447. World Meteorological Organization, Geneva.
- World Meteorological Organization (WMO). 1992. WMO WDCGG Data Report, Part A (Carbon Dioxide), WDCGG No. 2. World Meteorological Organization, Geneva.
CITE AS: Sladkovic, R., H.E. Scheel, and W. Seiler. 1994. Atmospheric CO2 records from sites operated by the Fraunhofer Institute for Atmospheric Environmental Research. In Trends: A Compendium of Data on Global Change. Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, U.S. Department of Energy, Oak Ridge, Tenn., U.S.A.