Eastern Equatorial Pacific SST and Isotope Data During Heinrich Stadial 1 Kienast, S.S.; Friedrich, T.; Dubois, N.; Hill, P.S.; Timmermann, A.; Mix, A.C.; Kienast, M. Kienast, S.S. Friedrich, T. Dubois, N. Hill, P.S. Timmermann, A. Mix, A.C. Kienast, M. Heinrich Events Sea Surface Temperature Reconstruction earth science/paleoclimate/paleoceanography (delta 18O,Cibicidoides sp.,null,per mil PDB,null,paleoceanography,null,null,N,>150um) earth science/paleoclimate/paleoceanography (delta 13C,Cibicidoides sp.,null,per mil PDB,null,paleoceanography,null,null,N,>150um) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,based on Koutavas and Sachs (2008)) earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,C,null) earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (232Th,sediment,null,microgram per square meter per year,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 18O,Cibicidoides sp.,one standard deviation,per mil PDB,null,paleoceanography,null,null,N,>150um) earth science/paleoclimate/paleoceanography (238U,sediment,null,disintegration per minute per gram,null,paleoceanography,null,null,N,for detrital minerals; estimated by multiplying 232Th (dpm/g)*0.7) earth science/paleoclimate/paleoceanography (238U,sediment,null,disintegration per minute per gram,null,paleoceanography,null,null,N,for authigenic minerals; estimated by 238U-238U detrital) earth science/paleoclimate/paleoceanography (230Th,sediment,null,gram per square meter per year,null,paleoceanography,null,null,N,from Francois et al. 2004) earth science/paleoclimate/paleoceanography (230Th,sediment,null,disintegration per minute per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 15N,sediment,null,per mil PDB,null,paleoceanography,corrected,null,N,-0.7 per mil for instrument drift) earth science/paleoclimate/paleoceanography (230Th,sediment,unspecified margin of error,disintegration per minute per gram,null,paleoceanography,null,null,N,analytical uncertainty) earth science/paleoclimate/paleoceanography (230Th excess,sediment,null,disintegration per minute per gram,null,paleoceanography,corrected,null,N,corrected for ingrowth of 230Th from detrital and authigenic U and decay since deposition) earth science/paleoclimate/paleoceanography (232Th,sediment,null,disintegration per minute per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 13C,Cibicidoides sp.,one standard deviation,per mil PDB,null,paleoceanography,null,null,N,>150um) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (238U,sediment,null,disintegration per minute per gram,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean earth science/paleoclimate/paleocean (V19-30>LATITUDE -3>LONGITUDE -83) (TR163-31P>LATITUDE -3.62>LONGITUDE -83.97) (ME0005-24JC>LATITUDE .021667>LONGITUDE -86.463) In this study, we use records of nitrogen isotope ratios (d15N), UK'37 temperature estimates, organic carbon and opal percentages from high-resolution sediment cores located in the eastern equatorial Pacific (EEP) to explore the mechanisms linking millennial-scale changes in low-latitude sea surface temperature, water column denitrification and surface productivity to the timing of northern or southern polar climate during the last 100,000 yr. Our results support a hypothesis that the Southern Hemisphere, and its connection to the low latitudes via shallow subsurface ocean circulation, has a primary influence on the biogeochemistry of the EEP. In addition, our results suggest that, during the last glacial stage, denitrification rates fluctuated on millennial timescales in response to water-column ventilation rather than upstream oxidant demand in intermediate-depth waters. However, due to the poor age constraints available for Marine Isotopic Stage (MIS) 3, the EEP sedimentary data presented here could support two conflicting mechanisms, one driven by enhanced intermediate overturning circulation in the Southern Ocean during Heinrich Events/Antarctic Warm Events, implying that subsurface flow rates control thermocline ventilation, and a second one consistent with more sluggish intermediate circulation during Antarctic Warm Events and giving a central role to the temperature control on oxygen solubility in Southern Ocean surface waters. STUDY NOTES: Notes on Thorium measurements: 230Th xs,o refers to the measured value as corrected for ingrowth of 230Th from detrital and authigenic uranium. These values are calculated using the measured concentrations of 230Th, 232Th and 238U, and assuming that all 232Th is detrital in origin. It also assumes a detrital 238U/232Th ratio of 0.7. In nature, this ratio can be variable. Concentrations are corrected for decay since deposition. 230Th-norm flux refers to the 230Th-normalized bulk sediment mass accumulation rate (or flux). 232Th flux refers to the 230Th-normalized flux of Thorium-232. This flux is calculated as 230Th-norm flux * 232Th (micro g/g) Note that 232Th (micro g/g) = 232Th (dpm/g) * (1/246186) * 10^6 Please refer to Francois et al. (2004) for more detail on this proxy. Note that the 230Th xs,o data of cores ME0005-24JC and TR163-31P given here differ slightly from those originally published by Kienast et al. 2007 due a) the use of an updated age model here and b) a minor spread sheet error in the earlier publication. Neither update affects the conclusions reached in the earlier study in any way. For core V19-30, 230Th, 232Th, and 238U data can be found in Hayes et al. 2010. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Kienast, S.S. Investigator : Friedrich, T. Investigator : Dubois, N. Investigator : Hill, P.S. Investigator : Timmermann, A. Investigator : Mix, A.C. Investigator : Kienast, M. 2014-02-04 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/16016 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-v19-30.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-me24-cib.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-tr31-thor.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-me24-thor.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/EEP_kienast2013.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-me24-uvi.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-v19-30.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-me24-cib.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-tr31-thor.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-me24-thor.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/EEP_kienast2013.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-me24-uvi.txt English https://www.ncdc.noaa.gov/paleo/study/16016 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-v19-30.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-me24-cib.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-tr31-thor.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-me24-thor.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/EEP_kienast2013.xls https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/kienast2013/kienast2013-me24-uvi.txt Kienast, S.S., T. Friedrich, N. Dubois, P.S. Hill, A. Timmermann, A.C. Mix, and M. Kienast2013Near collapse of the meridional SST gradient in the eastern equatorial Pacific during Heinrich Stadial 1Paleoceanography28663-67410.1002/2013PA002499 Koutavas, A., and J.P. Sachs2008Northern timing of deglaciation in the eastern equatorial Pacific from alkenone paleothermometryPaleoceanography23PA420510.1029/2008PA001593 Kienast, S.S., M. Kienast, A.C. Mix, S.E. Calvert, and R. François2007 Thorium-230 normalized particle flux and sediment focusing in the Panama Basin region during the last 30,000 yearsPaleoceanography22PA221310.1029/2006PA001357 Dubois, N., M. Kienast, S. Kienast, C. Normandeau, S.E. Calvert, T.D. Herbert, and A. Mix. 2011. Millennial-scale variations in hydrography and biogeochemistry in the Eastern Equatorial Pacific over the last 100 kyr. Quaternary Science Reviews, Vol. 30, pp. 210-223. doi:10.1016/j.quascirev.2010.10.012 Martin, P A., D.W. Lea, Y. Rosenthal, N.J. Shackleton, M. Sarnthein, and T. Papenfuss2002Quaternary deep sea temperature histories derived from benthic foraminiferal Mg/CaEarth and Planetary Science Letters198193-20910.1016/S0012-821X(02)00472-7 Francois, R., M. Frank, M.M.R. v. d. Loeff, and M.P. Bacon2004230Th normalization: An essential tool for interpreting sedimentary fluxes during the late QuaternaryPaleoceanography19PA101810.1029/2003PA000939 START YEAR: 51470 cal yr BP * END YEAR: 1760 cal yr BP -86.463 -3.62 -83 .021667