# Atmospheric CO2 20 Million Year Foraminiferal B/Ca Reconstruction #----------------------------------------------------------------------- # World Data Center for Paleoclimatology, Boulder # and # NOAA Paleoclimatology Program #----------------------------------------------------------------------- # NOTE: Please cite Publication, and Online_Resource and date accessed when using these data. # If there is no publication information, please cite Investigators, Title, and Online_Resource and date accessed. # # # Online_Resource: https://www.ncdc.noaa.gov/paleo/study/16154 # # Online_Resource: http://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/tripati2011/tripati2011isotope.txt # # Description/Documentation lines begin with # # Data lines have no # # # Archive: Paleoceanography #-------------------- # Contribution_Date # Date: 2014-03-09 #-------------------- # Title # Study_Name: Atmospheric CO2 20 Million Year Foraminiferal B/Ca Reconstruction #-------------------- # Investigators # Investigators: Tripati, A.K.; Roberts, C.D.; Eagle, R.A.; Li, G. #-------------------- # Description_and_Notes # Description: Paleoatmospheric CO2 concentrations estimated from the boron/calcium ratio of planktonic foraminifera. # Samples from Deep Sea Drilling Project Site 588 and Ocean Drilling Program Site 806 were used to reconstruct pCO2 # values from the Miocene through Holocene (~20 to 0 Ma). Average, maximum, and minimum pCO2 estimates are calculated # for each time. #-------------------- # Publication # Authors: Aradhna K. Tripati, Christopher D. Roberts, Robert A. Eagle, Gaojun Li # Published_Date_or_Year: 2011-05-15 # Published_Title: A 20 million year record of planktic foraminiferal B/Ca ratios: Systematics and uncertainties in pCO2 reconstructions # Journal_Name: Geochimica et Cosmochimica Acta # Volume: 75 # Edition: # Issue: 10 # Pages: 2582-2610 # DOI: 10.1016/j.gca.2011.01.018 # Online_Resource: http://www.sciencedirect.com/science/article/pii/S0016703711000263 # Full_Citation: # Abstract: We use new and published data representing a 20 million long record to discuss the systematics of interpreting planktic foraminiferal B/Ca ratios. B/Ca-based reconstructions of seawater carbonate chemistry and atmospheric pCO2 assume that the incorporation of boron into foraminiferal tests can be empirically described by an apparent partition coefficient, KD=(B/CaCaCO3)/(BOH4-/HCO3- seawater) (Hemming and Hanson, 1992). It has also been proposed that there is a species-specific relationship between KD and temperature (Yu et al., 2007). As we discuss, although these relationships may be robust, there remain significant uncertainties over the controls on boron incorporation into foraminifera. It is difficult to be certain that the empirically defined correlation between temperature and KD is not simply a result of covariance of temperature and other hydrographic variables in the ocean, including carbonate system parameters. There is also some evidence that KD may be affected by solution [HCO3-]/[CO32-] ratios (i.e., pH), or by [CO32-]. In addition, the theoretical basis for the definition of KD and for a temperature control on KD is of debate. We also discuss the sensitivity of pCO2 reconstructions to different KD-temperature calibrations and seawater B/Ca. If a KD-temperature calibration is estimated using ice core pCO2 values between 0 and 200 ka, B/Ca ratios can be used to reasonably approximate atmospheric pCO2 between 200 and 800 ka; however, the absolute values of pCO2 calculated are sensitive to the choice of KD-temperature relationship. For older time periods, the absolute values of pCO2 are also dependent on the evolution of seawater B concentrations. However, we find that over the last 20 Ma, reconstructed changes in declining pCO2 across the Mid-Pleistocene Transition, Pliocene glacial intensification, and the Middle Miocene Climate Transition are supported by the B/Ca record even if a constant coretop KD is used, or different KD-temperature calibrations and models of seawater B evolution are applied to the data. The inferred influence of temperature on KD from coretop data therefore cannot itself explain the structure of a published pCO2 reconstruction (Tripati et al., 2009). We conclude the raw B/Ca data supports a coupling between pCO2 and climate over the past 20 Ma. Finally, we explore possible implications of B/Ca-based pCO2 estimates for the interpretation of other marine pCO2 proxies. #------------------ # Funding_Agency # Funding_Agency_Name: National Environmental Research Council (UK) # Grant: #------------------ # Funding_Agency # Funding_Agency_Name: University of California - Los Angeles (USA) # Grant: #------------------ # Funding_Agency # Funding_Agency_Name: Magdalene College (UK) # Grant: #------------------ # Site_Information # Site_Name: DSDP588 # Location: Ocean>Pacific Ocean>South Pacific Ocean # Country: # Northernmost_Latitude: -26.1117 # Southernmost_Latitude: -26.1117 # Easternmost_Longitude: 161.2267 # Westernmost_Longitude: 161.2267 # Elevation: -1533 m #------------------ # Site_Information # Site_Name: ODP806 # Location: Ocean>Pacific Ocean>North Pacific Ocean # Country: # Northernmost_Latitude: 0.3187 # Southernmost_Latitude: 0.3187 # Easternmost_Longitude: 159.361 # Westernmost_Longitude: 159.361 # Elevation: -2521 m #------------------ # Data_Collection # Collection_Name: Tripati2011isotope # Earliest_Year: 20000000 # Most_Recent_Year: 0 # Time_Unit: Cal. Year BP # Core_Length: m # Notes: #------------------ # Chronology: # # #---------------- # Variables # # Data variables follow (have no #) # Data line variables format: Variables list, one per line, shortname-tab-longname-tab-longname components (9 components: what, material, error, units, seasonality, archive, detail, method, C or N for Character or Numeric data) ## notes-Hole Notes Hole, , , , , , , ,C ## notes-Core Notes Core, , , , , , , ,C ## notes-Section Notes Section, , , , , , , ,C ## depth_top Depth top of sample interval, , , cm, , , , section,N ## depth_bottom Depth bottom of sample interval, , , cm, , , , section,N ## notes-Species Notes Species, , , , , , , ,C ## d18OPDB delta 18O, , , PDB, , , , ,N ## d13CPDB delta 13C, , , PDB, , , , ,N #---------------- # Data: # Data lines follow (have no #) # Data line format - tab-delimited text, variable short name as header # Missing Values: # Stable isotope ratios, per mil, relative to Pee Dee Belemnite notes-Hole notes-Core notes-Section depth_top depth_bottom notes-Species d18OPDB d13CPDB 806A 1 1 9 11 G.ruber -2.31 1.58 806A 1 1 40 42 G.ruber -1.05 1.62 806A 1 1 80 82 G.ruber -1.52 1.48 806A 1 1 95 97 G.ruber -1.5 1.68 806A 1 1 120 122 G.ruber -1.29 1.42 806A 1 2 40 42 G.ruber -1.9 1.9 806A 1 2 42 44 G.sacculifer -1.28 2.14 806A 1 2 80 82 G.sacculifer -1.97 1.91 806A 1 2 90 92 G.sacculifer -1.64 1.75 806A 1 2 120 122 G.sacculifer -0.65 1.66 806A 1 3 37 39 G.ruber -1.26 1.37 806A 1 3 0 2 G.sacculifer -0.78 1.93 806A 1 3 72 74 G.sacculifer -1.39 1.86 806A 1 3 120 122 G.sacculifer -1.15 1.82 806A 1 4 0 2 G.ruber -1.84 1.64 806A 1 4 15 17 G.ruber -1.74 1.55 806A 1 4 40 42 G.ruber -1.16 1.22 806A 1 4 66 68 G.ruber -1.22 1.08 806A 1 4 110 112 G.ruber -1.49 1.9 806A 1 4 135 137 G.ruber -1.31 1.57 806A 1 4 80 82 G.sacculifer -1.06 1.96 806A 1 4 120 122 G.sacculifer -1.15 2.06 806A 1 5 42 44 G.ruber -1.94 1.47 806A 1 5 66 68 G.ruber -1.67 1.4 806A 1 5 0 2 G.sacculifer -1.21 1.86 806A 1 5 80 82 G.sacculifer -0.76 1.36 806A 1 5 135 137 G.sacculifer -1.14 1.75 806A 1 6 7 9 G.ruber -1.67 2.33 806A 2 1 0 2 G.ruber -1.78 1.47 806A 2 1 9 11 G.ruber -1.26 1.6 806A 2 1 40 42 G.ruber -1.46 1.81 806A 2 1 120 122 G.ruber -1.06 1.52 806A 2 1 66 68 G.sacculifer -0.42 2.18 806A 2 1 77 79 G.sacculifer -0.37 2.14 806A 2 1 127 129 G.sacculifer -0.4 2.19 806B 2 4 3 5 G.sacculifer -1.2 1.79 806B 2 4 34 36 G.sacculifer -0.74 1.84 806B 2 4 139 141 G.sacculifer -1.21 2.02 806B 2 5 88 90 G.ruber -1.67 1.48 806B 2 5 13 15 G.sacculifer -0.96 1.97 806B 2 5 78 80 G.sacculifer -1.14 1.72 806B 2 5 134 136 G.sacculifer -0.74 1.92 806B 2 6 58 60 G.ruber -1.19 1.66 806B 2 6 118 120 G.sacculifer -1.33 1.7 806B 2 6 138 140 G.sacculifer -0.95 1.52 806B 2 7 8 10 G.sacculifer -0.75 1.68 806B 2 7 24 26 G.sacculifer -0.71 1.67 806B 3 1 3 5 G.ruber -1.74 1.6 806B 3 1 43 45 G.ruber -4.96 -0.56 806B 3 1 108 110 G.ruber -1.63 1.37 806B 3 1 134 136 G.ruber -1.68 1.42 806B 3 1 143 145 G.ruber -1.7 1.4 806B 3 2 11 13 G.ruber -1.54 1.42 806B 3 2 38 40 G.ruber -0.95 0.64 806B 3 2 113 115 G.ruber -1.14 0.73 806B 3 2 133 135 G.ruber -1.15 1.23 806B 3 2 74 76 G.sacculifer -0.67 1.69 806B 3 3 3 5 G.ruber -1.43 1.55 806B 3 3 24 26 G.ruber -1.9 1.01 806B 3 3 129 131 G.ruber -1.38 1.48 806B 3 4 114 116 G.ruber -1.43 1.64 806B 3 4 64 66 G.sacculifer -1.11 1.95 806B 3 5 23 25 G.ruber -1.3 1.17 806B 3 5 73 75 G.ruber -1.67 1.53 806B 3 5 103 105 G.ruber -1.51 1.74 806B 3 5 133 135 G.ruber -1.22 1.68 806B 3 5 143 145 G.ruber -1.5 1.63 806B 3 6 39 41 G.ruber -0.53 1.9 806B 3 6 108 110 G.ruber -1.66 1.88 806B 3 6 133 135 G.ruber -1.56 1.66 806B 3 6 78 80 G.sacculifer -1.03 1.63 806B 4 1 8 10 G.ruber -1.38 1.42 806B 4 1 43 45 G.ruber -1.34 1.85 806B 4 1 67 69 G.ruber -1.36 1.41 806B 4 1 144 146 G.ruber -1.32 1.45 806B 4 2 25 27 G.ruber -1.41 1.86 806B 4 2 81 83 G.ruber -1.59 1.53 806B 4 2 134 136 G.sacculifer -1.18 1.87 806B 4 3 0 2 G.ruber -1.51 1.85 806B 4 3 19 21 G.ruber -1.55 1.52 806B 4 3 38 40 G.ruber -1.44 1.59 806B 4 3 60 62 G.ruber -1.37 1.6 806B 4 3 98 100 G.ruber -1.41 2.06 806B 4 3 123 125 G.ruber -1.3 1.47 806B 4 3 139 141 G.ruber -1.4 1.33 806B 4 4 3 5 G.ruber -1.57 1.29 806B 4 4 19 21 G.ruber -1.42 1.84 806B 4 4 41 43 G.ruber -1.45 1.51 806B 4 4 60 62 G.ruber -1.66 1.77 806B 6 5 44 46 G.ruber -1.88 1.68 806B 6 5 124 126 G.ruber -1.53 2.26 806B 6 5 4 6 G.sacculifer -1.55 2.4 806B 6 5 23 25 G.sacculifer -1.32 2.04 806B 6 5 86 88 G.sacculifer -1.22 2.08 806B 6 5 144 146 G.sacculifer -1.07 2.13 806B 6 6 4 6 G.sacculifer -1.24 1.97 806B 6 6 18 20 G.sacculifer -1.26 2.21 806B 6 6 64 66 G.sacculifer -1.27 2.13 806B 6 6 78 80 G.sacculifer -1.3 2.17 806B 6 6 138 140 G.sacculifer -1.04 1.76 806B 6 7 4 6 G.sacculifer -0.77 2.08 806B 6 7 24 26 G.sacculifer -0.6 2.07 806B 6 7 65 67 G.sacculifer -0.93 1.96 806B 6 7 85 87 G.sacculifer -1.23 2.2 806B 7 1 59 61 G.sacculifer -1.22 2.09 806B 7 3 98 100 G.sacculifer -1.32 2.2 806B 7 6 105 107 G.sacculifer -1.5 2.3 806B 8 1 125 127 G.sacculifer -1.34 2.05 806B 8 4 49 51 G.sacculifer -1.45 1.98 806B 8 7 42 44 G.sacculifer -1.35 1.71 806B 9 1 78 80 G.sacculifer -1.38 2.29 806B 9 4 140 142 G.sacculifer -0.92 1.66 806B 9 6 20 22 G.sacculifer -1.38 2.05 806B 10 1 3 5 G.ruber -1.94 1.69 806B 10 1 22 24 G.ruber -1.67 1.72 806B 10 1 79 81 G.ruber -1.87 2.04 806B 10 1 99 101 G.ruber -1.71 1.93 806B 10 1 117 119 G.ruber -1.69 1.85 806B 10 1 138 140 G.ruber -1.88 2.17 806B 10 1 30 32 G.sacculifer -1.49 2.1 806B 10 2 20 22 G.ruber -1.72 1.77 806B 10 2 39 41 G.ruber -1.88 1.95 806B 10 2 59 61 G.ruber -1.87 2.4 806B 10 2 98 100 G.ruber -1.71 1.95 806B 10 3 40 42 G.ruber -1.33 1.72 806B 10 4 58 60 G.ruber -1.43 1.64 806B 17 5 59 61 G.sacculifer -1.17 1.97 806B 17 5 138 140 G.sacculifer -1.16 1.86 806B 17 CC 9 11 G.sacculifer -1.15 2.02 806B 18 CC 3 5 G.sacculifer -0.77 2.32 806B 19 CC 4 6 G.sacculifer -1.48 2.24 806B 20 CC 4 6 G.sacculifer -1.46 2.16 806B 21 CC 5 7 G.sacculifer -0.91 2.18 806B 22 CC 7 9 G.sacculifer -1.17 2.2 806B 23 CC 7 9 G.sacculifer -1.18 1.99 806B 24 CC 14 16 G.sacculifer -0.9 2.21