The past 5000 years history of solar modulation of cosmic radiation from 10 Be and 14 C studies

• Published in: Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society 1990
• Subjects: Byrd; Byrd Station; Antarc*; Antarctica; ice core
• Online Access: http://dx.doi.org/10.1098/rsta.1990.0028; https://royalsocietypublishing.org/doi/pdf/10.1098/rsta.1990.0028

10 Be is produced in a similar way as 14 C by the interaction of cosmic radiation with the nuclei in the atmosphere. Assuming that the 10 Be and 14 C variation are proportional and considering the different behaviour in the Earth system, the 10 Be concentrations in ice cores can be compared with the 14 C variations in tree rings. A high correlation is found for the short-term variations ( 14 C-Suess-wiggles). They reflect with a high probability production rate variations. More problematic is the interpretation of the long-term trends of 14 C and 10 Be. Several explanations are discussed. The reconstructed CO 2 concentrations in ice cores indicate a rather constant value (280 ± 10 p.p.m. by volume) during the past few millenia. Measurements on the ice core from Byrd Station, Antarctica, during the period 9000 to 6000 years BP indicate a decrease that might be explained by the extraction of CO 2 from the atmosphere-ocean system to build the terrestrial biomass pool during the climatic optimum.