Arctic Ocean stratification set by sea level and freshwater inputs since the last ice age
Abstract Salinity-driven density stratification of the upper Arctic Ocean isolates sea-ice cover and cold, nutrient-poor surface waters from underlying warmer, nutrient-rich waters. Recently, stratification has strengthened in the western Arctic but has weakened in the eastern Arctic; it is unknown...
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Online Access: | http://dx.doi.org/10.1038/s41561-021-00789-y https://www.nature.com/articles/s41561-021-00789-y.pdf https://www.nature.com/articles/s41561-021-00789-y |
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crspringernat:10.1038/s41561-021-00789-y 2023-05-15T14:32:22+02:00 Arctic Ocean stratification set by sea level and freshwater inputs since the last ice age Farmer, Jesse R. Sigman, Daniel M. Granger, Julie Underwood, Ona M. Fripiat, François Cronin, Thomas M. Martínez-García, Alfredo Haug, Gerald H. The Tuttle Fund of the Department of Geosciences of Princeton University, and from ExxonMobil through the Andlinger Center for Energy and the Environment of Princeton University Princeton | Princeton Environmental Institute, Princeton University National Science Foundation Max-Planck-Gesellschaft Department of the Interior | U.S. Geological Survey 2021 http://dx.doi.org/10.1038/s41561-021-00789-y https://www.nature.com/articles/s41561-021-00789-y.pdf https://www.nature.com/articles/s41561-021-00789-y en eng Springer Science and Business Media LLC https://creativecommons.org/licenses/by/4.0 https://creativecommons.org/licenses/by/4.0 CC-BY Nature Geoscience volume 14, issue 9, page 684-689 ISSN 1752-0894 1752-0908 General Earth and Planetary Sciences journal-article 2021 crspringernat https://doi.org/10.1038/s41561-021-00789-y 2022-01-04T13:59:16Z Abstract Salinity-driven density stratification of the upper Arctic Ocean isolates sea-ice cover and cold, nutrient-poor surface waters from underlying warmer, nutrient-rich waters. Recently, stratification has strengthened in the western Arctic but has weakened in the eastern Arctic; it is unknown if these trends will continue. Here we present foraminifera-bound nitrogen isotopes from Arctic Ocean sediments since 35,000 years ago to reconstruct past changes in nutrient sources and the degree of nutrient consumption in surface waters, the latter reflecting stratification. During the last ice age and early deglaciation, the Arctic was dominated by Atlantic-sourced nitrate and incomplete nitrate consumption, indicating weaker stratification. Starting at 11,000 years ago in the western Arctic, there is a clear isotopic signal of Pacific-sourced nitrate and complete nitrate consumption associated with the flooding of the Bering Strait. These changes reveal that the strong stratification of the western Arctic relies on low-salinity inflow through the Bering Strait. In the central Arctic, nitrate consumption was complete during the early Holocene, then declined after 5,000 years ago as summer insolation decreased. This sequence suggests that precipitation and riverine freshwater fluxes control the stratification of the central Arctic Ocean. Based on these findings, ongoing warming will cause strong stratification to expand into the central Arctic, slowing the nutrient supply to surface waters and thus limiting future phytoplankton productivity. Article in Journal/Newspaper Arctic Arctic Ocean Bering Strait Foraminifera* Phytoplankton Sea ice Springer Nature (via Crossref) Arctic Arctic Ocean Bering Strait Pacific Nature Geoscience 14 9 684 689 |
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Springer Nature (via Crossref) |
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English |
topic |
General Earth and Planetary Sciences |
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General Earth and Planetary Sciences Farmer, Jesse R. Sigman, Daniel M. Granger, Julie Underwood, Ona M. Fripiat, François Cronin, Thomas M. Martínez-García, Alfredo Haug, Gerald H. Arctic Ocean stratification set by sea level and freshwater inputs since the last ice age |
topic_facet |
General Earth and Planetary Sciences |
description |
Abstract Salinity-driven density stratification of the upper Arctic Ocean isolates sea-ice cover and cold, nutrient-poor surface waters from underlying warmer, nutrient-rich waters. Recently, stratification has strengthened in the western Arctic but has weakened in the eastern Arctic; it is unknown if these trends will continue. Here we present foraminifera-bound nitrogen isotopes from Arctic Ocean sediments since 35,000 years ago to reconstruct past changes in nutrient sources and the degree of nutrient consumption in surface waters, the latter reflecting stratification. During the last ice age and early deglaciation, the Arctic was dominated by Atlantic-sourced nitrate and incomplete nitrate consumption, indicating weaker stratification. Starting at 11,000 years ago in the western Arctic, there is a clear isotopic signal of Pacific-sourced nitrate and complete nitrate consumption associated with the flooding of the Bering Strait. These changes reveal that the strong stratification of the western Arctic relies on low-salinity inflow through the Bering Strait. In the central Arctic, nitrate consumption was complete during the early Holocene, then declined after 5,000 years ago as summer insolation decreased. This sequence suggests that precipitation and riverine freshwater fluxes control the stratification of the central Arctic Ocean. Based on these findings, ongoing warming will cause strong stratification to expand into the central Arctic, slowing the nutrient supply to surface waters and thus limiting future phytoplankton productivity. |
author2 |
The Tuttle Fund of the Department of Geosciences of Princeton University, and from ExxonMobil through the Andlinger Center for Energy and the Environment of Princeton University Princeton | Princeton Environmental Institute, Princeton University National Science Foundation Max-Planck-Gesellschaft Department of the Interior | U.S. Geological Survey |
format |
Article in Journal/Newspaper |
author |
Farmer, Jesse R. Sigman, Daniel M. Granger, Julie Underwood, Ona M. Fripiat, François Cronin, Thomas M. Martínez-García, Alfredo Haug, Gerald H. |
author_facet |
Farmer, Jesse R. Sigman, Daniel M. Granger, Julie Underwood, Ona M. Fripiat, François Cronin, Thomas M. Martínez-García, Alfredo Haug, Gerald H. |
author_sort |
Farmer, Jesse R. |
title |
Arctic Ocean stratification set by sea level and freshwater inputs since the last ice age |
title_short |
Arctic Ocean stratification set by sea level and freshwater inputs since the last ice age |
title_full |
Arctic Ocean stratification set by sea level and freshwater inputs since the last ice age |
title_fullStr |
Arctic Ocean stratification set by sea level and freshwater inputs since the last ice age |
title_full_unstemmed |
Arctic Ocean stratification set by sea level and freshwater inputs since the last ice age |
title_sort |
arctic ocean stratification set by sea level and freshwater inputs since the last ice age |
publisher |
Springer Science and Business Media LLC |
publishDate |
2021 |
url |
http://dx.doi.org/10.1038/s41561-021-00789-y https://www.nature.com/articles/s41561-021-00789-y.pdf https://www.nature.com/articles/s41561-021-00789-y |
geographic |
Arctic Arctic Ocean Bering Strait Pacific |
geographic_facet |
Arctic Arctic Ocean Bering Strait Pacific |
genre |
Arctic Arctic Ocean Bering Strait Foraminifera* Phytoplankton Sea ice |
genre_facet |
Arctic Arctic Ocean Bering Strait Foraminifera* Phytoplankton Sea ice |
op_source |
Nature Geoscience volume 14, issue 9, page 684-689 ISSN 1752-0894 1752-0908 |
op_rights |
https://creativecommons.org/licenses/by/4.0 https://creativecommons.org/licenses/by/4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1038/s41561-021-00789-y |
container_title |
Nature Geoscience |
container_volume |
14 |
container_issue |
9 |
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op_container_end_page |
689 |
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