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Assessment of C, N and Si isotope tracers associated to past ocean productivity
  • +8
  • Jesse Farmer,
  • Jennifer Hertzberg,
  • Damien Cardinal,
  • Susanne Fietz,
  • Katharine Hendry,
  • Sam Jaccard,
  • Adina Paytan,
  • Patrick Rafter,
  • Haojia Ren,
  • Christopher Somes,
  • Jill Sutton
Jesse Farmer
Department of Geosciences, Princeton University, Department of Geosciences, Princeton University

Corresponding Author:[email protected]

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Jennifer Hertzberg
Old Dominion University, Old Dominion University
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Damien Cardinal
LOCEAN (UMR7159), Sorbonne Université, IRD, CNRS, MNHN, LOCEAN (UMR7159), Sorbonne Université, IRD, CNRS, MNHN
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Susanne Fietz
Stellenbosch University, Stellenbosch University
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Katharine Hendry
University of Bristol,University of Bristol, University of Bristol,University of Bristol
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Sam Jaccard
University of Lausanne, University of Lausanne
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Adina Paytan
University of California, Santa Cruz, University of California, Santa Cruz
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Patrick Rafter
University of California Irvine, University of California Irvine
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Haojia Ren
National Taiwan University, National Taiwan University
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Christopher Somes
GEOMAR Helmholtz Centre for Ocean Research Kiel, GEOMAR Helmholtz Centre for Ocean Research Kiel
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Jill Sutton
Univ Brest, CNRS, IRD, Ifremer, Institut Universitaire Européen de la Mer, LEMAR, Univ Brest, CNRS, IRD, Ifremer, Institut Universitaire Européen de la Mer, LEMAR
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Abstract

Biological productivity in the ocean directly influences the partitioning of carbon between the atmosphere and ocean interior, thereby controlling the distributions of many elements and their isotopes in the ocean. Through this carbon cycle feedback, changing ocean productivity has long been hypothesized as a key pathway for modulating past atmospheric carbon dioxide levels and hence global climate. To reconstruct climate impacts from temporal changes in paleoproductivity, robust proxies are needed to test the connection between past ocean productivity, nutrient biogeochemistry, ocean circulation and climate. Here we compile water column carbon (C), nitrogen (N) and silicon (Si) stable isotopes from GEOTRACES-era data in four key ocean regions to review geochemical proxies of oceanic carbon and nutrient partitioning based on the C, N, and Si isotopic composition of marine sediments. Relationships between water column isotope distributions, ocean productivity, and nutrient utilization are discussed. The potential for isotope measurements in sedimentary archives to record aspects of past ocean productivity are evaluated, along with key uncertainties and limitations associated with each proxy. Constraints on past ocean productivity, nutrient cycling and utilization during late Quaternary glacial-interglacial cycles and over the Cenozoic are examined. This review highlights opportunities for future research using multielement proxy applications and emphasizes the importance of such applications to reconstructing Cenozoic climate evolution.