Abstract
At K-puszta, Hungary, the atmospheric concentration of carbon dioxide has been measured since 1981 as part of the WMO BAPMoN program. The time-series is self-consistent, even though the data have not been corrected for the carrier-gas effect. Assuming a linear trend, the rate of increase of the concentration is 1.82 ppm/year. The paper presents the strong daily and seasonal variations which are caused mainly by the vegetation. The temporal course of the growth rate shows similarities with those observed at the NOAA baseline stations, although the seasonal cycle is a few weeks ahead of those of Mauna Loa and Point Barrow.