Published online by Cambridge University Press: 18 July 2016
The Krakow Radiocarbon Laboratory has been measuring isotope composition of atmospheric CO2 and its natural concentration in the Kraków region for the last five years. We have been sampling on a continuous basis in two-week intervals at ca 20m above ground level, close to the center of Kraków. CO2 was sorbed while slow pumping atmospheric air through a molecular sieve. After recovery by heating, the CO2 was converted to benzene and 14C measured in a liquid scintillation spectrometer. In a small portion of CO2 δ13C was determined in a mass spectrometer. Concentration of CO2 was assessed by measurement of the volumes of the sorbed CO2 and the pumped air. A five-year record (1983–1987) reveals a multi-annual linear trend and winter-summer oscillations. Calculated parameters of the regression line (intercept and slope) for the measured δ14C, δ13C and concentration are: 222 (Jan 1983) and −15.5/yr, −9.57% (Jan 1983) and −0.042/yr, 336ppm (Jan 1983) and 1.4ppm/yr, respectively.