noaa-forcing-24030 Paleo-pCO2 Database Middle Miocene ODP761 Boron Isotope and CO2 Data Greenop, R.; Foster, G.L.; Wilson, P.A.; Lear, C.H. Paleo-pCO2 Database Middle Miocene ODP761 Boron Isotope and CO2 Data 2018-05-09 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/24030 Investigator R. Greenop Investigator G.L. Foster Investigator P.A. Wilson Investigator C.H. Lear earth science paleoclimate climate forcing|climate reconstructions|paleoceanography age,null,null,million years ago,null,climate forcing|climate reconstructions|paleoceanography,null,null,N,null earth science paleoclimate paleoceanography magnesium/calcium,planktic foraminifer,null,millimole per mole,null,paleoceanography,null,null,N,Trilobatus trilobus earth science paleoclimate climate forcing|paleoceanography carbon dioxide,bulk atmosphere,null,parts per million,null,climate forcing|paleoceanography,null,null,N,based on planktic foram delta 11B earth science paleoclimate climate forcing|paleoceanography carbon dioxide,bulk atmosphere,two standard deviations lower bound,parts per million,null,climate forcing|paleoceanography,null,null,N,based on planktic foram delta 11B earth science paleoclimate paleoceanography delta 11B,planktic foraminifer,null,per mil,null,paleoceanography,null,null,N,Trilobatus trilobus earth science paleoclimate climate forcing|paleoceanography carbon dioxide,bulk atmosphere,two standard deviations upper bound,parts per million,null,climate forcing|paleoceanography,null,null,N,based on planktic foram delta 11B earth science paleoclimate paleoceanography delta 11B,planktic foraminifer,two standard deviations,per mil,null,paleoceanography,null,null,N,Trilobatus trilobus earth science paleoclimate climate forcing carbon dioxide geoscientificInformation 17110000 cal yr BP 15540000 cal yr BP Complete -16.737167 -16.737167 115.535 115.535 -2168 -2168 Ocean Indian Ocean ODP 761C>LATITUDE -16.737167>LONGITUDE 115.535 None Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site. English DOC/NOAA/NESDIS/NCEI National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce https://www.ncdc.noaa.gov/data-access/paleoclimatology-data DATA Center Contact Bruce Bauer bruce.a.bauer@noaa.gov paleo@noaa.gov 303-497-6280 303-497-6513

325 Broadway, E/NE31

Boulder CO 80305-3328 USA online ASCII Rosanna Greenop, Gavin L. Foster, Paul A. Wilson, Caroline H. Lear 2014 Paleoceanography and Paleoclimatology 29 9 845-853 10.1002/2014PA002653 https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1002/2014PA002653

The amplitude of climatic change, as recorded in the benthic oxygen isotope record, has varied throughout geological time. During the late Pleistocene, changes in the atmospheric concentration of carbon dioxide (CO2) are an important control on this amplitude of variability. The contribution of CO2 to climate variability during the pre-Quaternary however is unknown. Here we present a new boron isotope-based CO2 record for the transition into the middle Miocene Climatic Optimum (MCO) between 15.5 and 17 Myr that shows pronounced variability between 300 ppm and 500 ppm on a roughly 100 kyr time scale during the MCO. The CO2 changes reconstructed for the Miocene are ~2 times larger in absolute terms (300 to 500 ppm compared to 180 to 280 ppm) than those associated with the late Pleistocene and ~15% larger in terms of climate forcing. In contrast, however, variability in the contemporaneous benthic oxygen isotope record (at ~1 permil) is approximately two thirds the amplitude of that seen during the late Pleistocene. These observations indicate a lower overall sensitivity to CO2 forcing for Miocene (Antarctic only) ice sheets than their late Pleistocene (Antarctic plus lower latitude northern hemisphere) counterparts. When our Miocene CO2 record is compared to the estimated changes in contemporaneous d18Osw (ice volume), they point to the existence of two reservoirs of ice on Antarctica. One of these reservoirs appears stable, while a second reservoir shows a level of dynamism that contradicts the results of coupled climate-ice sheet model experiments given the CO2 concentrations that we reconstruct. STUDY NOTES: Paleo-CO2 derived from boron isotope measurements on marine sediment core ODP761B for the middle Miocene (~17 - 15 million years ago), contributed to the Paleo-pCO2 Database

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/greenop2014odp761boron.txt NOAA Template File; Middle Miocene ODP761 Boron Isotope and CO2 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/greenop2014odp761boron.xlsx Excel File; Middle Miocene ODP761 Boron Isotope and CO2 Data USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11