- Garmisch-Partenkirchen
Germany
Grassland valley
47°28' N, 11°03' E
Graphics
Digital Data
R. Sladkovic, H.E. Scheel, W. Seiler
1978-92
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.
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.
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.
12/03/97