Clim. Past Discuss., 8, 621-636, 2012
© Author(s) 2012. This work is distributed
under the Creative Commons Attribution 3.0 License.
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This discussion paper has been under review for the journal Climate of the Past (CP). Please refer to the corresponding final paper in CP.
Rapid coupling of Antarctic temperature and atmospheric CO2 during deglaciation
J. B. Pedro1,2, S. O. Rasmussen3, and T. D. van Ommen2,4
1Antarctic Climate & Ecosystems Cooperative Research Centre, University of Tasmania, Hobart, Tasmania, Australia
2Institute of Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
3Centre for Ice and Climate, University of Copenhagen, Copenhagen, Denmark
4Australian Antarctic Division, Kingston, Tasmania, Australia

Abstract. Antarctic ice cores provide clear evidence of a close coupling between variations in Antarctic temperature and the atmospheric concentration of CO2 during the glacial/interglacial cycles of the past 800 thousand years. Precise information on the relative timing of the temperature and CO2 changes can assist in refining our understanding of the physical processes involved in this coupling. Here, we focus on the last deglaciation, 19 000 to 11 000 years before present, during which CO2 concentrations increased by ~80 parts per million by volume and Antarctic temperature increased by ~10 °C. Utilising a recently developed proxy for regional Antarctic temperature, derived from five near-coastal ice cores, and two ice core CO2 records with high dating precision, we show that the increase in CO2 lagged the increase in regional Antarctic temperature by only 0–400 years. This new value for the lag, consistent for both CO2 records, implies a faster feedback between temperature and CO2 than the centennial to millennial-scale lags suggested by previous studies.

Citation: Pedro, J. B., Rasmussen, S. O., and van Ommen, T. D.: Rapid coupling of Antarctic temperature and atmospheric CO2 during deglaciation, Clim. Past Discuss., 8, 621-636, doi:10.5194/cpd-8-621-2012, 2012.
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