Reconstructed pCO2 Data Estimated from Regional d13C Gradients Over Last 1.5Ma Lisiecki, L.E. Lisiecki, L.E. earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/climate forcing (carbon dioxide,null,null,parts per million,null,climate forcing,null,null,N,estimated from Ddelta 13C_PDW-NA/2) earth science/paleoclimate/paleocean (Global>LATITUDE >LONGITUDE ) A high-resolution marine proxy for atmospheric pCO2 is needed to clarify the phase lag between pCO2 and marine climate proxies and to provide a record of orbital-scale pCO2 variations before the oldest ice core measurement at 800 ka. Benthic d13C data should record deep ocean carbon storage and, thus, atmospheric pCO2. This study finds that a modified d13C gradient between the deep Pacific and intermediate North Atlantic (Dd13CP-NA/2) correlates well with pCO2. Dd13CP-NA/2 reproduces characteristic differences between pCO2 and ice volume during Late Pleistocene glaciations and indicates that pCO2 usually leads terminations by 0.2-3.7 kyr but lags by 3-10 kyr during two failed terminations at 535 and 745 ka. Dd13CP-NA/2 gradually transitions from 41- to 100-kyr cyclicity from 1.3-0.7 Ma but has no secular trend in mean or amplitude since 1.5 Ma. The minimum pCO2 of the last 1.5 Myr is estimated to be 155 ppm at 920 ka. STUDY NOTES: Dd13CP-NA/2 is calculated as the difference between regional stacks of benthic d13c on the LR04 benthic d18O age model (Lisiecki and Raymo, 2005). More precisely, Dd13CP-NA/2 is deep Pacific d13c minus 0.5 times the intermediate-depth North Atlantic d13c, scaled to the mean and standard deviation of ice core pCO2 from 0-800 ka. For stack data, see Lisiecki (2010), A simple mixing explanation for late Pleistocene changes in the Pacific-South Atlantic benthic d13C gradient, Clim. Past, 6, 305-314. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Lisiecki, L.E. 2013-12-12 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/15695 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/lisiecki2010-grl/lisiecki2010-grl.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/lisiecki2010-grl/lisiecki2010-grl.txt English https://www.ncdc.noaa.gov/paleo/study/15695 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/lisiecki2010-grl/lisiecki2010-grl.txt Lisiecki, L.E.2010A benthic d13C-based proxy for atmospheric pCO2 over the last 1.5 MyrGeophysical Research Letters37L2170810.1029/2010GL045109 START YEAR: 1500000 cal yr BP * END YEAR: 0 cal yr BP -180 -90 180 90