Atmospheric carbon dioxide record from Waldhof, Germany

Graphics Digital Data

W. Fricke, M. Wallasch

Umweltbundesamt, Frankfurter Str. 135, 63067 Offenbach/Main, Germany

Period of Record

1972-93

Methods

Air samples are collected from air intake lines. Continuous monitoring of atmospheric CO2 is accomplished by alternating a flowing sample of ambient air with two reference gases of known concentrations. Determinations of CO2 are made using a Siemens ULTRAMAT-3 nondispersive infrared gas analyzer. Before entering the analyzer, all gases are dried by passing them through a glass water vapor trap immersed in a cold alcohol bath. Mixtures of CO2-in-N2 are used for calibration gases. At Schauinsland, CO2-in-air calibration gases were used until September 1, 1991. More details about the UBA air sampling network and the methods used are provided in Grosch et al. (1981), Levin (1991), and Levin et al. (1994).

Only technically biased values resulting from calibration problems or equipment malfunctions are removed. Daily values are calculated on the basis of half-hourly mean values. Carrier gas corrections have been determined experimentally and applied on the basis of five CO2-in-air standards calibrated by Scripps Institution of Oceanography in 1988. The relative precision of the half-hourly readings is ~1 part per million by volume (ppmv).

Waldhof, Germany
Agricultural and forest environment
on the North German lowland, subject
to pollution sources

Trends

Annual atmospheric CO2 concentrations at Waldhof rose from 346.82 parts per million by volume (ppmv) in 1972 to 372.09 ppmv in 1993. The Waldhof site is subject to pollution sources; consequently, the monthly atmospheric CO2 record exhibits a large seasonal amplitude.

References

Grosch, W., W. Fleck, and D. Jost. 1981.
The increase of carbon dioxide at rural sites of Germany. Berichte aus dem Meßnetz des Umweltbundesamtes.

Levin, I. 1991.
Der Beitrag der fossilen Energieträger zum CO2-Haushalt über dem europäischen Kontinent. Abschlußbericht zum Forschungsvorhaben FE 104 02627

Levin, I., R. Graul, and N.B.A. Trivett, 1994
Long term observations of atmospheric CO2 and carbon isotopes at continental sites in Germany. Tellus (in press).

CITE AS: Fricke, W., and M. Wallasch. 1994. Atmospheric CO2 records from sites in the UBA air sampling network. 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.

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12/01/97