Coupled climate and subarctic Pacific nutrient upwelling over the last 850,000 years

Worne, Savannah; Kender, Sev; Swann, George E.A.; Leng, Melanie J.; Ravelo, Ana Christina

Abstract

High latitude deep water upwelling has the potential to control global climate over glacial timescales through the biological pump and ocean-atmosphere CO2 exchange. However, there is currently a lack of continuous long nutrient upwelling records with which to assess this mechanism. Here we present geochemical proxy records for nutrient upwelling and glacial North Pacific Intermediate Water (GNPIW) formation in the Bering Sea over the past 850 kyr, which demonstrates that glacial periods were characterised by reduced nutrient upwelling, when global atmospheric CO2 and temperature were also lowered. We suggest that glacial expansion of sea ice in the Bering Sea, and the simultaneous expansion of low nutrient GNPIW, inhibited vertical mixing and nutrient supply across the subarctic Pacific Ocean. Our findings lend support to the suggestion that high latitude sea ice and the resultant intermediate water formation, modulated deep water upwelling and ocean-atmosphere CO2 exchange on glacial-interglacial timescales.

Citation

Worne, S., Kender, S., Swann, G. E., Leng, M. J., & Ravelo, A. C. (2019). Coupled climate and subarctic Pacific nutrient upwelling over the last 850,000 years. Earth and Planetary Science Letters, 522, 87-97. https://doi.org/10.1016/j.epsl.2019.06.028

• Journal Article Type: Article
• Acceptance Date: Jun 20, 2019
• Online Publication Date: Jul 5, 2019
• Publication Date: Sep 15, 2019
• Deposit Date: Jun 20, 2019
• Publicly Available Date: Jul 6, 2020
• Journal: Earth and Planetary Science Letters
• Print ISSN: 0012-821X
• Electronic ISSN: 0012-821X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 522
• Article Number: 87-97
• Pages: 87-97
• DOI: https://doi.org/10.1016/j.epsl.2019.06.028
• Keywords: upwelling; sea ice; CO2; subarctic; Bering Sea; glacial
• Public URL: https://nottingham-repository.worktribe.com/output/2213902
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0012821X1930367X
• Additional Information: This article is maintained by: Elsevier; Article Title: Coupled climate and subarctic Pacific nutrient upwelling over the last 850,000 years; Journal Title: Earth and Planetary Science Letters; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.epsl.2019.06.028; Content Type: article; Copyright: © 2019 Elsevier B.V. All rights reserved.
• Contract Date: Jun 25, 2019