Ventilation of northern and southern sources of aged carbon in the eastern equatorial Pacific during the Younger Dryas rise in atmospheric CO2

noaa-ocean-25430 Bulk sediment nitrogen isotopes from the northern Peru Margin over the last 25 kyr Bova, S.C.; Herbert, T.D.; Altabet, M.A. Bulk sediment nitrogen isotopes from the northern Peru Margin over the last 25 kyr 2018-10-12 NCDC-Paleoclimatology ONLINE Files Pending https://www.ncdc.noaa.gov/paleo/study/25430 Investigator S.C. Bova Investigator T.D. Herbert Investigator M.A. Altabet earth science paleoclimate paleoceanography delta 15N,sediment,null,per mil,null,paleoceanography,null,isotope ratio mass spectrometry,N,null earth science paleoclimate paleoceanography sample identification,null,null,null,null,paleoceanography,null,null,C,sample identification used by 14C laboratory earth science paleoclimate paleoceanography age,benthic foraminifer,null,radiocarbon year before present,null,paleoceanography,null,accelerator mass spectrometry,N,null earth science paleoclimate paleoceanography age,null,null,calendar year before present,null,paleoceanography,null,null,N,null earth science paleoclimate paleoceanography age,benthic foraminifer,one standard deviation,radiocarbon year,null,paleoceanography,null,accelerator mass spectrometry,N,null earth science paleoclimate paleoceanography depth,null,null,centimeter,null,paleoceanography,null,null,N,null earth science paleoclimate paleocean carbon isotopes earth science paleoclimate paleocean nitrogen isotopes geoscientificInformation 28238 cal yr BP 1102 cal yr BP Complete -3.986 -1.252167 -89.698 -81.134167 -1023 -370 Ocean Pacific Ocean Eastern Pacific Ocean KNR195-5 CDH41>LATITUDE -1.265667>LONGITUDE -89.698 Ocean Pacific Ocean Eastern Pacific Ocean KNR195-5 CDH26>LATITUDE -3.986>LONGITUDE -81.308667 Ocean Pacific Ocean Eastern Pacific Ocean KNR195-5 GGC43>LATITUDE -1.252167>LONGITUDE -89.6845 Ocean Pacific Ocean Eastern Pacific Ocean KNR195-5 CDH23>LATITUDE -3.749167>LONGITUDE -81.134167 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 Bova, S.C., Herbert, T.D., and Altabet M.A. 2018 Ventilation of northern and southern sources of aged carbon in the eastern equatorial Pacific during the Younger Dryas rise in atmospheric CO2 Paleoceanography and Paleoclimatology in press

Atmospheric carbon dioxide (CO2) levels rose by ~90 ppmv during the last deglaciation, but the source of this carbon remains unknown. One popular hypothesis suggests carbon accumulated in the deep Southern Ocean, becoming increasingly radiocarbon (14C)-depleted during the last glacial period, and was released into Antarctic Intermediate Water (AAIW) and, subsequently, the atmosphere during deglaciation. Detection of extremely 14C-deplete carbon in the intermediate-depth tropical oceans during periods of atmospheric CO2 rise was initially considered the "smoking gun" for the hypothesis, but attempts to reproduce the anomalies closer to the Southern Ocean source have largely failed. Here, we present new 14C records from four cores recovered at intermediate depths in the eastern equatorial Pacific (EEP). In the context of additional geochemical records, including benthic foraminiferal stable isotopes and sedimentary nitrogen isotopes, we demonstrate that the extreme 14C anomalies observed during the last deglaciation do not reflect the radiocarbon content of AAIW. We show that, although AAIW likely transported modestly 14C-deplete carbon to the EEP subsurface, the extreme 14C signatures might reflect a distinct source of aged carbon arriving from the north, suggesting the North Pacific helped transport deep ocean carbon to the atmosphere during the last deglaciation. In the EEP, additional local hydrothermal inputs of 14C-free carbon near the Galapagos Islands magnified the already low-14C signatures. Finally, regardless of arrival route (North/South Pacific or hydrothermal), 14C-deplete carbon was released from the EEP subsurface during a late deglacial pulse of renewed upwelling, likely contributing to the Younger Dryas rise in atmospheric CO2. STUDY NOTES: Provided Keywords: deglaciation, upwelling, Younger Dryas

GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/bova2018/bova2018-cdh23-14c.txt NOAA Template File; KNR195-5 CDH23 14C Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/bova2018/bova2018-cdh26-d15n.txt NOAA Template File; KNR195-5 CDH26 d15N Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/bova2018/bova2018-cdh41-14c.txt NOAA Template File; KNR195-5 CDH41 14C Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/bova2018/bova2018-cdh26-14c.txt NOAA Template File; KNR195-5 CDH26 14C Data GET DATA https://www1.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/bova2018/bova2018-ggc43-14c.txt NOAA Template File; KNR195-5 GGC43 14C Data USA/NOAA DIF Version 9.8.4 2018-12-11 2018-12-11