Agulhas Plateau 360KYr Stable Isotope Data Ziegler, M.; Diz, P.; Hall, I.R.; Zahn, R. Ziegler, M. Diz, P. Hall, I.R. Zahn, R. earth science/paleoclimate/paleoceanography (delta 18O,benthic foraminifer,null,per mil PDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 13C,benthic foraminifer,null,per mil PDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 13C,Globorotalia truncatulinoides,null,per mil PDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 13C,null,null,per mil PDB,null,paleoceanography,differenced,null,N,thermocline - deepwater) earth science/paleoclimate/paleoceanography (delta 13C,null,null,per mil PDB,null,paleoceanography,differenced|smoothed,null,N,thermocline - deepwater; 3pt running mean) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,smoothed,null,N,3 pt. running mean) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (MD02-2588>LATITUDE -41.33167>LONGITUDE 25.82833) The rise in atmospheric CO2 concentrations observed at the end of glacial periods has, at least in part, been attributed to the upwelling of carbon-rich deep water in the Southern Ocean. The magnitude of outgassing of dissolved CO2, however, is influenced by the biological fixation of upwelled inorganic carbon and its transfer back to the deep sea as organic carbon. The efficiency of this biological pump is controlled by the extent of nutrient utilization, which can be stimulated by the delivery of iron by atmospheric dust particles. Changes in nutrient utilization should be reflected in the δ13C gradient between intermediate and deep waters. Here we use the δ13C values of intermediate- and bottom-dwelling foraminifera to reconstruct the carbon isotope gradient between thermocline and abyssal water in the subantarctic zone of the South Atlantic Ocean over the past 360,000 years. We find millennial-scale oscillations of the carbon isotope gradient that correspond to changes in dust flux and atmospheric CO2 concentrations as reported from Antarctic ice cores. We interpret this correlation as a relationship between the efficiency of the biological pump and fertilization by dust-borne iron. As the correlation is exponential, we suggest that the sensitivity of the biological pump to dust-borne iron fertilization may be increased when the background dust flux is low. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Ziegler, M. Investigator : Diz, P. Investigator : Hall, I.R. Investigator : Zahn, R. 2013-04-10 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/14194 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ziegler2013/ziegler2013ther-deep.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ziegler2013/ziegler2013-plank.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ziegler2013/ziegler2013-benthic.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ziegler2013/ziegler2013ther-deep.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ziegler2013/ziegler2013-plank.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ziegler2013/ziegler2013-benthic.txt English https://www.ncdc.noaa.gov/paleo/study/14194 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ziegler2013/ziegler2013ther-deep.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ziegler2013/ziegler2013-plank.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/ziegler2013/ziegler2013-benthic.txt Ziegler, M., Diz, P., Hall, I.R., Zahn, R. 2013. Millennial-scale changes in atmospheric CO2 levels linked to the Southern Ocean carbon isotope gradient and dust flux. Nature Geoscience, online publication 7-Apr-2013. DOI:10.1038/NGEO1782. START YEAR: 353180 cal yr BP * END YEAR: 29000 cal yr BP 25.82833 -41.33167 25.82833 -41.33167