Late glacial climate history from ice cores

• Main Authors: Oeschger, H., Beer, J., Siegenthaler, U., Stauffer, B., Dansgaard, W., Langway, C.C.
• Other Authors: Jansen, James E., Takahashi, Taro
• Format: Book Part
• Language: English
• Published: American Geophysical Union 1984
• Subjects: 530 Physics; Greenland; Dye 3; Dye-3; Greenland ice cores; ice core; Ice Sheet
• Online Access: https://boris.unibe.ch/160967/1/Oeschger_Late_glacial_climate_history_from_ice_cores.pdf; https://boris.unibe.ch/160967/

Ice cores contain information on climatic variations and their causes. Recent results obtained on the new deep ice core drilled in 1981 at Dye 3, South Greenland, in the frame of the US-Danish-Swiss Greenland Ice Sheet Program, are: - Comparison of the θ18O variations in the Greenland ice cores with those in European lake carbonate exhibits strong similarities and provides time marks (13,000, 11,000, 10,000 B.P.) for the Late Glacial section of the ice cores; - CO2 concentration measurements in the occluded air indicate low (180–200 ppm) CO2 concentration 30,000 to 15,000 B.P. and an increase to ca. 300 ppm around 13,000 B.P. The CO2 increase might reflect a change in the ocean circulation at the end of the last glaciation and could have contributed to the establishment of the Holocene environmental conditions; - 10Be concentration measurements on samples covering the last 50,000 years show a correlation with θ18O, low θ18O values corresponding to high 10Be concentrations (atoms per g of ice). It is likely that this correlation primarily reflects changes in the rate of precipitation in the northern hemisphere. Based on the ice core information, climatic events during the Glacial-Postglacial transition are discussed.