noaa-ocean-10513 Atlantic Coretop Foraminiferal Mg/Ca and d18O Calibration Data Arbuszewski, J.A.; deMenocal, P.B.; Kaplan, A.; Farmer, E.C. Atlantic Coretop Foraminiferal Mg/Ca and d18O Calibration Data 2011-01-26 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/10513 Investigator J.A. Arbuszewski Investigator P.B. deMenocal Investigator A. Kaplan Investigator E.C. Farmer earth science paleoclimate paleocean geochemistry earth science paleoclimate paleocean oxygen isotopes geoscientificInformation 10 cal yr BP -10 cal yr BP Complete 42.85 42.85 -25.15 -25.15 -3448 -3448 Ocean Atlantic Ocean North Atlantic Ocean VM29-178>LATITUDE 42.85>LONGITUDE -25.15 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 Arbuszewski, J., P. deMenocal, A. Kaplan, and E.C. Farmer. 2010. On the fidelity of shell-derived d18Oseawater estimates. Earth and Planetary Science Letters, Vol. 300, Issues 3-4, pp. 185-196, 1 December 2010. doi:10.1016/j.epsl.2010.10.035

Paired foraminiferal Magnesium/Calcium ratio and oxygen isotope analyses are widely used to estimate surface ocean d18Oseawater, a robust proxy for surface salinity. We assess the fidelity of shell-derived d18Oseawater estimates for the surface-dwelling foraminifer Globigerinoides ruber (white) using an Atlantic meridional coretop transect spanning basin-scale temperature and salinity gradients. Shell-derived and observed d18Oseawater values are well correlated (r2=0.77), but a large systematic bias is observed. Shell Mg/Ca ratios are significantly elevated above values expected from observed and isotopic calcification temperatures in the saline subtropical gyres of both hemispheres. This temperature-independent shell Mg/Ca ratio variability, termed "excess Mg/Ca", is highly correlated with surface salinity (r2=0.77), and the observed salinity dependence (27±4%) is much higher than indicated by culture studies (6±2%). Our coretop data are used to develop new Atlantic Basin temperature and salinity calibration equations that are accurate (±1.1°C and ±0.20, respectively), precise (r2=0.82 and 0.81, respectively), and verifiable using previously published data. These results are valid for the relatively high salinities of the subtropical Atlantic (35.5-37.3). We discover that inclusion of other published data from lower salinity regions (< 35) indicates little or no excess Mg/Ca. Taken together, these results point to a strongly non-linear, positive salinity effect on shell Mg/Ca ratios that significantly affects the accuracy of SST and d18Oseawater estimates in high salinity settings (>35). STUDY NOTES: Coretop foraminiferal magnesium/calcium ratio and oxygen isotope data from a meridional transect of 64 Atlantic samples. Mg/Ca ratio and d18O measured on Globigerinoides ruber (white) are used to evaluate shell-derived d18Oseawater estimates across different salinity regimes in the Atlantic Ocean.

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2010/arbuszewski2010.txt GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/arbuszewski2010/arbuszewski2010.xls USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11