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Foraminiferal isotope evidence of reduced nitrogen fixation in the ice age Atlantic Ocean

Ren, H. and Sigman, D. M. and Meckler, A. N. and Plessen, B. and Robinson, R. S. and Rosenthal, Y. and Haug, G. H. (2009) Foraminiferal isotope evidence of reduced nitrogen fixation in the ice age Atlantic Ocean. Science, 323 (5911). pp. 244-248. ISSN 0036-8075. doi:10.1126/science.1165787.

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Fixed nitrogen (N) is a limiting algal nutrient in the low latitude ocean, and the oceanic N inventory has been suggested to increase during ice ages so as to lower atmospheric CO_2. In organic matter within planktonic foraminifera shells in Caribbean Sea sediments, the ^(15)N/^(14)N from the last ice age is higher than that from the current interglacial, indicating higher nitrate ^(15)N/^(14)N in the Caribbean thermocline. This and species-specific differences are best explained by less N fixation in the Atlantic during the last ice age. The fixation decrease was most likely a response to a known ice age reduction in ocean N loss, and it would have worked to balance the ocean N budget and to curb ice age-to-interglacial change in the N inventory.

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Sigman, D. M.0000-0002-7923-1973
Additional Information:© 2008 American Association for the Advancement of Science. 10 September 2008; accepted 25 November 2008. Published online 18 December 2008. Originally published in Science Express on 18 December 2008. We thank J. Bernhard and D. McCorkle for supplying surface sediment samples, Y. Wang, M. Coray, and S. Bishop for technical assistance, and B. Brunelle for advice, and two anonymous reviewers for comments. This work was supported by the US NSF through grants ANT- 0453680, OCE-9981479, and OCE-0447570 to D. M. S., OCE-0220776, OCE-0341412 and OCE-0502504 to Y. R., and OCE-0437366 and OCE-0350794 to J. Bernhard, and by BP through the Princeton Carbon Mitigation Initiative, and by the Deutsche Forschungsgemeinschft (DFG) through grants to G. H. H. This research used samples provided by the ODP, which is sponsored by the US NSF and participating countries under the management of Joint Oceanographic Institutions.
Funding AgencyGrant Number
NSFOCE- 9981479
NSFOCE- 0447570
Schlanger Ocean Drilling FellowshipUNSPECIFIED
Princeton Carbon Mitigation InitiativeUNSPECIFIED
Deutsche ForschungsgemeinschaftUNSPECIFIED
Issue or Number:5911
Record Number:CaltechAUTHORS:20090430-145756006
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:14128
Deposited By: Tony Diaz
Deposited On:11 Aug 2009 17:42
Last Modified:08 Nov 2021 22:43

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