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Atmospheric CO2 Record from In Situ Measurements at K-Puszta, Hungary

graphics Graphics   data Data


László Haszpra
Hungarian Meteorological Service,
Institute for Atmospheric Physics,
Department for Analysis of Atmospheric Environment, H-1675,
P.O. Box 39, Budapest, Hungary

Period of Record



The K-puszta regional background air pollution monitoring station was established in a clearing in a mixed forest on the Hungarian Great Plain in the middle of the Carpathian Basin. K-puszta is as free from direct pollution as possible in the highly industrialized, densely populated central Europe. Because of the growing vegetation, the station was moved in September 1993 to a larger clearing, also at the same elevation, approximately 500 m from the original site. The region is climatologically calm. Prevailing winds come from the northwest and the annual average wind speed is 2 m/s. The nearest large city is Kecskemét (population 110,000), located 15 km southeast from the station. The nearest major pollution source in the prevailing wind direction is Budapest (population 1.9 million), approximately 70 km from the station.


Air samples are collected continuously through an air intake located 10 m above ground. The air samples and standard gases to be analyzed are saturated by water vapor at room temperature and cooled to 4°C. This stabilizes the water content of the gas to be analyzed and makes it possible to compensate for the influence of the water content on the measurement. Determinations of CO2 are made through the use of a Siemens Ultramat 3 nondispersive infrared (NDIR) analyzer. The instrument is regularly calibrated against CO2-in-air standards obtained from NOAA CMDL Carbon Cycle Group.

Data Recording, Reduction, Calculation, and Reporting

Since April 1984, concentration values have been recorded by a digital data acquisition system. Before April 1984, half-hour concentration values were determined manually from stripchart records. Only data recorded during instrument malfunctions are removed from the data record. The annual average concentrations are calculated from monthly values and monthly values are calculated from daily means. Taking into account the significant daily and seasonal variations in CO2 concentrations caused by local vegetative influences, daily means are calculated only when both daytime and nighttime periods are represented. The monthly average is calculated only when at least ten daily means are available for the calculation. For the calculation of the annual averages the representation of both the summer and winter periods is required. Data are expressed in parts per million relative to the WMO 1985 mole fraction scale. These data are also available from the World Data Centre for Greenhouse Gases (Tokyo, Japan).

Map showing location of K-puszta, Hungary

K-puszta, Hungary
Forest clearing
46°58' N, 19°33' E
125 m above MSL


The yearly mean atmospheric CO2 concentration at K-puszta, Hungary increased from 354.1 parts per million (ppm) in 1981 to 377.0 ppm in 1997. Because the K-puszta station is located in a clearing of a forested area on the Hungarian Great Plain, it is subject to significant biospheric effects. As a result, the record from K-puszta shows high seasonal and interannual variability. However, the trends and temporal features of the K-puszta record parallel those observed at other Northern Hemisphere baseline air pollution monitoring stations (Haszpra 1995).


  • Borbelykiss, I., L. Haszpra, E. Koltay, S. Laszlo, A. Meszaros, E. Meszaros, and G. Szabo. 1988. Elemental concentrations and regional signatures in atmospheric aerosols over Hungary. Physica Scripta 37(2):299-304.
  • Haszpra, L. 1989. The atmospheric carbon budget and its influence on Earth's climate. In I. Pais (ed.), Proceedings of the Biogeochemical Cycle of Elements in Nature (May 10, 1989). Budapest.
  • Haszpra, L. 1995. Carbon dioxide concentration measurements at a rural site in Hungary. Tellus 47:17-22
  • Köhlor, A. 1974. Bemerkungen über die Messung der CO2-Konzentration in Gegenwart von Wasserdampf. Staub-Reinhaltung der Luft 34: 305-307.

CITE AS: Haszpra, L. 1998. Atmospheric CO2 record from in situ measurements at K-puszta, Hungary. 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, Tennessee, U.S.A.