Equatorial Pacific 1.1 Million Year Nitrogen Isotope Data Rafter, P.A.; Charles, C.D. Rafter, P.A. Charles, C.D. earth science/paleoclimate/paleoceanography (age,null,null,calendar kiloyear before present,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (delta 15N,sediment,null,per mil,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,C,ODP Site) earth science/paleoclimate/paleoceanography (delta 18O,Uvigerina sp.,null,per mil PDB,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,C,Site) earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,C,SectionID2) earth science/paleoclimate/paleoceanography (notes,null,null,null,null,paleoceanography,null,null,C,SectionID) earth science/paleoclimate/paleoceanography (depth,null,null,centimeter,null,paleoceanography,null,null,N,null) earth science/paleoclimate/paleocean (ODP 849>LATITUDE .18>LONGITUDE -110.52) (ODP 806B>LATITUDE .32>LONGITUDE 159.35) (RC13-112>LATITUDE -1.2>LONGITUDE -101) There is little agreement among models in predicting the average state of the tropical Pacific when subjected to enhanced greenhouse gas forcing. This uncertainty emphasizes the importance of reconstructing past variability in tropical Pacific climate through episodes of significant and estimable radiative forcing. Thus far, efforts along these lines have concentrated primarily on inferences of sea surface temperature variability from deep-sea sediments. Here we offer a different view of the equatorial Pacific over the past ~1.2 million years (Myr) - before and after the mid-Pleistocene shift in the structure of ice ages. The zonal gradient in the nitrogen isotopic composition of sediment across the equatorial Pacific reflects nutrient delivery to the surface and, by extension, ocean dynamical properties. Over the last ~1.2 Myr, the variability of eastern equatorial Pacific nutrient upwelling (inferred from relative nitrate utilization) was highly correlated with local seasonal insolation. By contrast, nitrate utilization was insensitive to the 100,000 year cycle that dominated many other aspects of the Pleistocene ice ages, including greenhouse gas concentrations. A strong linear relationship between relative nitrate utilization and seasonal insolation over the past ~1 million years suggests a predictable response of one primary determinant of tropical Pacific climate change. STUDY NOTES: Nitrogen isotope (d15N) data from Equatorial Pacific sediment cores for the past 1.1 million years NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Rafter, P.A. Investigator : Charles, C.D. 2012-12-11 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/13607 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012odp806.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012rc13-112.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012rndb74p.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012odp849.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012dd15n.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012odp806.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012rc13-112.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012rndb74p.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012odp849.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012dd15n.txt English https://www.ncdc.noaa.gov/paleo/study/13607 https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012odp806.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012rc13-112.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012rndb74p.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012odp849.txt https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/rafter2012/rafter2012dd15n.txt Patrick A. Rafter and Christopher D. Charles. 2012. Pleistocene equatorial Pacific dynamics inferred from the zonal asymmetry in sedimentary nitrogen isotopes. Paleoceanography, Vol. 27, PA3102. DOI: 10.1029/2012PA002367 START YEAR: 1148000 cal yr BP * END YEAR: 3000 cal yr BP -110.52 -1.2 159.35 .32