noaa-forcing-24330 Paleo-pCO2 Database Middle Miocene Boron Isotope and CO2 Data Foster, G.L.; Lear, C.H.; Rae, J.W.B. Paleo-pCO2 Database Middle Miocene Boron Isotope and CO2 Data 2018-05-30 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/24330 Investigator G.L. Foster Investigator C.H. Lear Investigator J.W.B. Rae earth science paleoclimate paleoceanography delta 11B,Trilobatus sacculifer,null,per mil,null,paleoceanography,null,ion chromatography|multiple collector inductively-coupled plasma mass spectrometry,N,null earth science paleoclimate climate reconstructions|paleoceanography pH,delta 11B,null,dimensionless,null,climate reconstructions|paleoceanography,null,null,N,null earth science paleoclimate climate reconstructions|paleoceanography sea surface temperature,magnesium/calcium,null,degree Celsius,null,climate reconstructions|paleoceanography,null,null,N,null 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 delta 11B,Trilobatus sacculifer,two standard deviations,per mil,null,paleoceanography,null,ion chromatography|multiple collector inductively-coupled plasma mass spectrometry,N,null earth science paleoclimate paleoceanography magnesium/calcium,Trilobatus sacculifer,null,millimole per mole,null,paleoceanography,null,null,N,null 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 11B of Globigerinoides sacculifer earth science paleoclimate climate reconstructions|paleoceanography pH,delta 11B,two standard deviations upper bound,dimensionless,null,climate reconstructions|paleoceanography,null,null,N,null 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 11B of Globigerinoides sacculifer earth science paleoclimate climate reconstructions|paleoceanography pH,delta 11B,two standard deviations lower bound,dimensionless,null,climate reconstructions|paleoceanography,null,null,N,null earth science paleoclimate climate forcing|paleoceanography carbon dioxide,bulk atmosphere,null,parts per million,null,climate forcing|paleoceanography,null,null,N,based on 11B of Globigerinoides sacculifer earth science paleoclimate climate forcing carbon dioxide geoscientificInformation 16380000 cal yr BP 12280000 cal yr BP Complete -16.737167 3.72 -42.92 115.535 -3598 -2168 Ocean Indian Ocean ODP 761C>LATITUDE -16.737167>LONGITUDE 115.535 Ocean Atlantic Ocean North Atlantic Ocean ODP 926>LATITUDE 3.72>LONGITUDE -42.92 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

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Boulder CO 80305-3328 USA online ASCII Gavin L. Foster, Caroline H. Lear, James W.B. Rae 2012 Earth and Planetary Science Letters 341-344 243-254 10.1016/j.epsl.2012.06.007 https://www.sciencedirect.com/science/article/pii/S0012821X12002919

The middle Miocene Climatic Optimum (17-15 Ma; MCO) is a period of global warmth and relatively high CO2 and is thought to be associated with a significant retreat of the Antarctic Ice Sheet (AIS). We present here a new planktic foraminiferal d11B record from 16.6 to 11.8 Ma from two deep ocean sites currently in equilibrium with the atmosphere with respect to CO2. These new data demonstrate that the evolution of global climate during the middle Miocene (as reflected by changes in the cyrosphere) was well correlated to variations in the concentration of atmospheric CO2. What is more, within our sampling resolution (~1 sample per 300 kyr) there is no evidence of hysteresis in the response of ice volume to CO2 forcing during the middle Miocene, contrary to what is understood about the Antarctic Ice Sheet from ice sheet modelling studies. In agreement with previous data, we show that absolute levels of CO2 during the MCO were relatively modest (350-400 ppm) and levels either side of the MCO are similar or lower than the pre-industrial (200-260 ppm). These new data imply the presence of either a very dynamic AIS at relatively low CO2 during the middle Miocene or the advance and retreat of significant northern hemisphere ice. Recent drilling on the Antarctic margin and shore based studies indicate significant retreat and advance beyond the modern limits of the AIS did occur during the middle Miocene, but the complete loss of the AIS was unlikely. Consequently, it seems that ice volume and climate variations during the middle Miocene probably involved a more dynamic AIS than the modern but also some component of land-based ice in the northern hemisphere. STUDY NOTES: Paleo-CO2 derived from boron isotope measurements on planktonic foraminifera samples from two Ocean Drilling Program cores, contributed to the Paleo-pCO2 Database.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/foster2012boron.txt NOAA Template File; Middle Miocene Boron Isotope and CO2 Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/climate_forcing/trace_gases/Paleo-pCO2/foster2012boron.xlsx Excel File; Middle Miocene Boron Isotope and CO2 Data USA/NOAA DIF Version 9.8.4 2019-06-07 2019-06-07