Silicic Acid Cycling in the Bering Sea During the Mid-Pleistocene Transition
The rate of deep-ocean carbon burial is considered important for modulating glacial-interglacial atmospheric CO2 concentrations and global climate during the Quaternary. It has been suggested that glacial iron fertilization and increased efficiency of the biological pump in the Southern Ocean since...
Published in: | Paleoceanography and Paleoclimatology |
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2022
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Online Access: | https://doi.org/10.1029/2021PA004284 https://nottingham-repository.worktribe.com/file/7355068/1/Silicic%20Acid%20Cycling%20in%20the%20Bering%20Sea%20During%20the%20Mid-Pleistocene%20Transition https://nottingham-repository.worktribe.com/output/7355068 |
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ftunnottinghamrr:oai:nottingham-repository.worktribe.com:7355068 2023-05-15T15:43:25+02:00 Silicic Acid Cycling in the Bering Sea During the Mid-Pleistocene Transition Worne, Savannah Swann, George E.A. Kender, Sev Lacey, Jack H. Leng, Melanie J. 2022-01-29 https://doi.org/10.1029/2021PA004284 https://nottingham-repository.worktribe.com/file/7355068/1/Silicic%20Acid%20Cycling%20in%20the%20Bering%20Sea%20During%20the%20Mid-Pleistocene%20Transition https://nottingham-repository.worktribe.com/output/7355068 unknown https://nottingham-repository.worktribe.com/output/7355068 Paleoceanography and Paleoclimatology Volume 37 Issue 2 doi:https://doi.org/10.1029/2021PA004284 https://nottingham-repository.worktribe.com/file/7355068/1/Silicic%20Acid%20Cycling%20in%20the%20Bering%20Sea%20During%20the%20Mid-Pleistocene%20Transition 2572-4517 doi:10.1029/2021PA004284 openAccess http://creativecommons.org/licenses/by/4.0/ CC-BY Paleontology Atmospheric Science Oceanography Geography: Geosciences Journal Article publishedVersion 2022 ftunnottinghamrr https://doi.org/10.1029/2021PA004284 2022-10-13T22:17:10Z The rate of deep-ocean carbon burial is considered important for modulating glacial-interglacial atmospheric CO2 concentrations and global climate during the Quaternary. It has been suggested that glacial iron fertilization and increased efficiency of the biological pump in the Southern Ocean since the Mid-Pleistocene Transition (MPT) was key in lowering atmospheric pCO2 and facilitating rapid land ice accumulation. There is growing evidence that a similar mechanism may have existed in the subarctic Pacific Ocean, although this has not yet been assessed. Here, the silicon isotope composition of diatoms (δ30Sidiatom) from the Bering Sea upwelling region is used to assess the role of nutrient cycling on the subarctic Pacific biological pump during the MPT. Results show that during and after the “900kyr event,” the high productivity green belt zone was characterized by low silicic acid utilization but high supply, coincident with the dominance of diatom resting spores. We posit that as nutrient upwelling was suppressed following pack ice growth and expansion of glacial North Pacific Intermediate Water (GNPIW), primary productivity became nitrate-limited and enhanced opal remineralization caused a relative increase in silicic acid supply. However, preferential preservation and higher cellular carbon content of diatom resting spores, as well as increased supply of iron from expanded sea ice, likely sustained the net efficiency of the Bering Sea biological pump through the MPT. Remnant iron and silicic acid may also have propagated into the lower subarctic Pacific Ocean through GNPIW, aiding a regionally efficient biological pump at 900kyr and during post-MPT glacials. Article in Journal/Newspaper Bering Sea Sea ice Southern Ocean Subarctic University of Nottingham: Repository@Nottingham Southern Ocean Bering Sea Pacific Paleoceanography and Paleoclimatology 37 2 |
institution |
Open Polar |
collection |
University of Nottingham: Repository@Nottingham |
op_collection_id |
ftunnottinghamrr |
language |
unknown |
topic |
Paleontology Atmospheric Science Oceanography Geography: Geosciences |
spellingShingle |
Paleontology Atmospheric Science Oceanography Geography: Geosciences Worne, Savannah Swann, George E.A. Kender, Sev Lacey, Jack H. Leng, Melanie J. Silicic Acid Cycling in the Bering Sea During the Mid-Pleistocene Transition |
topic_facet |
Paleontology Atmospheric Science Oceanography Geography: Geosciences |
description |
The rate of deep-ocean carbon burial is considered important for modulating glacial-interglacial atmospheric CO2 concentrations and global climate during the Quaternary. It has been suggested that glacial iron fertilization and increased efficiency of the biological pump in the Southern Ocean since the Mid-Pleistocene Transition (MPT) was key in lowering atmospheric pCO2 and facilitating rapid land ice accumulation. There is growing evidence that a similar mechanism may have existed in the subarctic Pacific Ocean, although this has not yet been assessed. Here, the silicon isotope composition of diatoms (δ30Sidiatom) from the Bering Sea upwelling region is used to assess the role of nutrient cycling on the subarctic Pacific biological pump during the MPT. Results show that during and after the “900kyr event,” the high productivity green belt zone was characterized by low silicic acid utilization but high supply, coincident with the dominance of diatom resting spores. We posit that as nutrient upwelling was suppressed following pack ice growth and expansion of glacial North Pacific Intermediate Water (GNPIW), primary productivity became nitrate-limited and enhanced opal remineralization caused a relative increase in silicic acid supply. However, preferential preservation and higher cellular carbon content of diatom resting spores, as well as increased supply of iron from expanded sea ice, likely sustained the net efficiency of the Bering Sea biological pump through the MPT. Remnant iron and silicic acid may also have propagated into the lower subarctic Pacific Ocean through GNPIW, aiding a regionally efficient biological pump at 900kyr and during post-MPT glacials. |
format |
Article in Journal/Newspaper |
author |
Worne, Savannah Swann, George E.A. Kender, Sev Lacey, Jack H. Leng, Melanie J. |
author_facet |
Worne, Savannah Swann, George E.A. Kender, Sev Lacey, Jack H. Leng, Melanie J. |
author_sort |
Worne, Savannah |
title |
Silicic Acid Cycling in the Bering Sea During the Mid-Pleistocene Transition |
title_short |
Silicic Acid Cycling in the Bering Sea During the Mid-Pleistocene Transition |
title_full |
Silicic Acid Cycling in the Bering Sea During the Mid-Pleistocene Transition |
title_fullStr |
Silicic Acid Cycling in the Bering Sea During the Mid-Pleistocene Transition |
title_full_unstemmed |
Silicic Acid Cycling in the Bering Sea During the Mid-Pleistocene Transition |
title_sort |
silicic acid cycling in the bering sea during the mid-pleistocene transition |
publishDate |
2022 |
url |
https://doi.org/10.1029/2021PA004284 https://nottingham-repository.worktribe.com/file/7355068/1/Silicic%20Acid%20Cycling%20in%20the%20Bering%20Sea%20During%20the%20Mid-Pleistocene%20Transition https://nottingham-repository.worktribe.com/output/7355068 |
geographic |
Southern Ocean Bering Sea Pacific |
geographic_facet |
Southern Ocean Bering Sea Pacific |
genre |
Bering Sea Sea ice Southern Ocean Subarctic |
genre_facet |
Bering Sea Sea ice Southern Ocean Subarctic |
op_relation |
https://nottingham-repository.worktribe.com/output/7355068 Paleoceanography and Paleoclimatology Volume 37 Issue 2 doi:https://doi.org/10.1029/2021PA004284 https://nottingham-repository.worktribe.com/file/7355068/1/Silicic%20Acid%20Cycling%20in%20the%20Bering%20Sea%20During%20the%20Mid-Pleistocene%20Transition 2572-4517 doi:10.1029/2021PA004284 |
op_rights |
openAccess http://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2021PA004284 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
37 |
container_issue |
2 |
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1766377542107791360 |