- Reduced nitrate supply to the subarctic North Pacific (SNP) surface during the last ice age has been inferred from coupled changes in diatom-bound delta N-15 (DB-delta N-15), bulk sedimentary delta N-15, and biogenic fluxes. However, the reliability of bulk sedimentary and DB-delta N-15 has been questioned, and a previously reported delta N-15 minimum during Heinrich Stadial 1 (HS1) has proven difficult to explain. In a core from the western SNP, we report the foraminifera-bound delta N-15 (FB-delta N-15) in Neogloboquadrina pachyderma and Globigerina bulloides, comparing them with DB-delta N-15 in the same core over the past 25 kyr. The delta N-15 of all recorders is higher during the Last Glacial Maximum (LGM) than in the Holocene, indicating more complete nitrate consumption. N. pachyderma FB-delta N-15 is similar to DB-delta N-15 in the Holocene but 2.2% higher during the LGM. This difference suggests a greater sensitivity of FB-delta(15)NZ to changes in summertime nitrate drawdown and delta N-15 rise, consistent with a lag of theReduced nitrate supply to the subarctic North Pacific (SNP) surface during the last ice age has been inferred from coupled changes in diatom-bound delta N-15 (DB-delta N-15), bulk sedimentary delta N-15, and biogenic fluxes. However, the reliability of bulk sedimentary and DB-delta N-15 has been questioned, and a previously reported delta N-15 minimum during Heinrich Stadial 1 (HS1) has proven difficult to explain. In a core from the western SNP, we report the foraminifera-bound delta N-15 (FB-delta N-15) in Neogloboquadrina pachyderma and Globigerina bulloides, comparing them with DB-delta N-15 in the same core over the past 25 kyr. The delta N-15 of all recorders is higher during the Last Glacial Maximum (LGM) than in the Holocene, indicating more complete nitrate consumption. N. pachyderma FB-delta N-15 is similar to DB-delta N-15 in the Holocene but 2.2% higher during the LGM. This difference suggests a greater sensitivity of FB-delta(15)NZ to changes in summertime nitrate drawdown and delta N-15 rise, consistent with a lag of the foraminifera relative to diatoms in reaching their summertime production peak in this highly seasonal environment. Unlike DB-delta N-15, FB-delta N-15 does not decrease from the LGM into HS1, which supports a previous suggestion that the HS1 DB-delta N-15 minimum is due to contamination by sponge spicules. FB-delta N-15 drops in the latter half of the Bolling/Allerod warm period and rises briefly in the Younger Dryas cold period, followed by a decline into the mid-Holocene. The FB-delta N-15 records suggest that the coupling among cold climate, reduced nitrate supply, and more complete nitrate consumption that characterized the LGM also applied to the deglacial cold events.…
MetadatenAuthor details: | Haojia Ren, Anja S. Studer, Sascha Serno, Daniel M. Sigman, Gisela Winckler, Robert F. Anderson, Sergey Oleynik, Rainer Gersonde, Gerald H. Haug |
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DOI: | https://doi.org/10.1002/2014PA002765 |
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ISSN: | 0883-8305 |
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ISSN: | 1944-9186 |
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Title of parent work (English): | Paleoceanography |
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Publisher: | American Geophysical Union |
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Place of publishing: | Washington |
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Publication type: | Article |
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Language: | English |
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Year of first publication: | 2015 |
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Publication year: | 2015 |
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Release date: | 2017/03/27 |
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Volume: | 30 |
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Issue: | 9 |
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Number of pages: | 16 |
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First page: | 1217 |
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Last Page: | 1232 |
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Funding institution: | German Federal Ministry of Education and Research (BmBF); NOAA Climate
and Global Change Postdoctoral Fellowship; Academia Sinica Distinguished
Postdoctoral Fellowship; Taiwan MOST [103-2116-M-002-032-MY2]; US NSF
[OCE-1060947, PLR-1401489, 1060907]; Swiss NSF [200021_131886/1,
PBEZP2_145695]; Grand Challenges Program at Princeton University |
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Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Geowissenschaften |
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Peer review: | Referiert |
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Institution name at the time of the publication: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Erd- und Umweltwissenschaften |
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