Byrd and Siple Dome 9-21 ka CO2 data on GICC05 Timescale Pedro, J.B.; Rasmussen, S.O.; van Ommen, T.D. Pedro, J.B. Rasmussen, S.O. van Ommen, T.D. carbon cycle earth science/paleoclimate/climate forcing|ice cores (carbon dioxide,bulk atmosphere,one standard deviation,parts per million,null,climate forcing|ice cores,null,null,N,null) earth science/paleoclimate/climate forcing|ice cores (carbon dioxide,bulk atmosphere,null,parts per million,null,climate forcing|ice cores,null,null,N,null) earth science/paleoclimate/ice cores (depth,null,null,meter,null,ice cores,null,null,N,null) earth science/paleoclimate/ice cores (gas age,null,null,calendar year before present,null,ice cores,null,null,N,null) earth science/paleoclimate/ice core (Siple Dome>LATITUDE -81.65>LONGITUDE -148.82) (Byrd>LATITUDE -80.02>LONGITUDE -119.52) 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 at least 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 yr 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 likely lagged the increase in regional Antarctic temperature by less than 400 yr and that even a short lead of CO2 over temperature cannot be excluded. This result, consistent for both CO2 records, implies a faster coupling between temperature and CO2 than previous estimates, which had permitted up to millennial-scale lags. STUDY NOTES: CO2 data from the Byrd and Siple Dome ice cores placed on the Greenland Ice Core Chronology 2005 (GICC05) timescale for 9 - 21 KYrBP. The regional Antarctic temperature proxy data series is available elsewhere: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/antarctica2011iso.txt The locations and original references for the CO2 data and transfers to the GICC05 timescale are as follows: Byrd Location: 80°01’S 119°31’W Elevation: 1530 m asl Reference for transfer to GICC05 timescale: Pedro et al., Clim. Past. 8, 2012. Reference for CO2 data: (1) Neftel, A., Oeschger, H., Staffelbach, T., and Nature, 331, 609–611, doi:10.1038/331609a0, 1988. (2) Staffelbach, T., Stauffer, B., Sigg, A., and Oeschger, H.: CO2 measurements from polar ice cores – More data from different sites, Tellus B, 43, 91–96, doi:10.1034/j.1600-0889.1991.t01-1- 00003.x, 1991. Siple Dome Location: 81° 40'S 148° 49'W Elevation: 621 m asl Reference for transfer to GICC05 timescale: Pedro et al., Clim. Past. 8, 2012. Reference for CO2 data: Ahn, J., Wahlen, M., Deck, B. L., Brook, E. J., Mayewski, P. A., Taylor, K. C., and White, J. W. C.: A record of atmospheric CO2 during the last 40,000 years from the Siple Dome, Antarctica ice core, J. Geophys. Res., 109, D13305, doi:10.1029/2003JD004415, 2004. Byrd Ice Core: 80.01°S , 119.51°W; 1530 m elev. Siple Dome Ice Core, West Antarctica: 81°40'S, 148°49'W NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Pedro, J.B. Investigator : Rasmussen, S.O. Investigator : van Ommen, T.D. 2012-07-24 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/13139 https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/byrd/byrd-siple2012co2.xls https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/byrd/byrd-siple2012co2.txt https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/byrd/byrd-siple2012co2.xls https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/byrd/byrd-siple2012co2.txt English https://www.ncdc.noaa.gov/paleo/study/13139 https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/byrd/byrd-siple2012co2.xls https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/byrd/byrd-siple2012co2.txt Pedro, J.B., S.O. Rasmussen, and T.D. van Ommen. 2012. Tightened constraints on the time-lag between Antarctic temperature and CO2 during the last deglaciation. Clim. Past, 8, 1213-1221. www.clim-past.net/8/1213/2012/ doi:10.5194/cp-8-1213-2012 START YEAR: 21328 cal yr BP * END YEAR: 8580 cal yr BP -148.82 -81.65 -119.52 -80.02