Reconstruction of the Production Rate of Cosmogenic 14C in the Earth’s Atmosphere for 17 000–5000 BC

Resumo

Carbon isotope ¹⁴С is produced in the Earth’s atmosphere by energetic cosmic-ray (CR) particles. The data on its atmospheric abundance are used to reconstruct the rate of its production and to analyze past levels of CR intensity and solar activity. These data are obtained via measurement of the ¹⁴С abundance in tree rings, with their real age determined dendrochronologically. The ¹⁴С abundance depends on the carbon dioxide concentration in the atmosphere and on climatic changes that affect the processes of carbon exchange between natural reservoirs. The present study reports the results of reconstruction of the production rate for cosmogenic ¹⁴С in the Earth’s atmosphere in the interval from the onset of deglaciation (~17 000 BC) to the mid-Holocene. The climatic factors mentioned above were taken into account in this reconstruction.