Atmospheric Carbon Dioxide Record from Zugspitze
R. Sladkovic, H.E. Scheel, W. Seiler
Fraunhofer Institute for Atmospheric Environmental Research (IFU),
Period of Record
Ambient air has been measured continuously using URAS NDIR analyzers. From 1982 to 1990 a URAS 2T analyzer was used. Currently, a URAS 3G analyzer equipped with a continuously flushed reference cell is used. 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 about the measurements through 1985 are discussed in Reiter et al. (1986).
47°25' N, 10°59' E
The station at Zugspitze is located near the summit of the highest
mountain of the German Alps. In 1990, the site of CO2 sampling
was changed from a location 250 m below the summit to a new monitoring
station (2937 m above MSL) close to the mountain top. Compatibility
of the results was seen from measurements conducted in parallel at the
two sites for several months. Because of the high elevation of the
mountain station, the CO2 measurements at Zugspitze can be
considered free of regional contamination most of the time. Previously
reported monthly mean CO2 concentrations for Zugspitze
(cf. Trends '91; WMO WDCGG Data Report, 1992) were based on valid
data (only technically invalid data had been eliminated). In contrast,
the monthly concentrations given here were calculated from filtered
data that were considered indicative of background concentrations. Filtered
data consist only of measurements collected during specified conditions of
wind velocity (>4 m/s) and wind direction (225°-315°). Measurements
biased by local meteorology or by synoptic scale processes were removed
from the data by visual inspection. The differences between the annual
averages obtained from unfiltered data and the annual averages from filtered
data are typically
The mean annual CO2 concentrations at Zugspitze increased from 333.7 ppmv in 1981 to 349.4 ppmv in 1992. Variations of the annual growth rates were less pronounced than at the nearby stations Wank Peak (1776 m above MSL) and Garmisch-Partenkirchen (740 m above MSL).
- 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.