Atmospheric iron supply and marine productivity in the glacial North Pacific Ocean
Iron (Fe) is a key element in the Earth climate system, as it can enhance marine primary productivity in the high-nutrient low-chlorophyll (HNLC) regions where, despite a high concentration of major nutrients, chlorophyll production is low due to iron limitation. Eolian mineral dust represents one o...
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ftdoajarticles:oai:doaj.org/article:88f28e96299b416c895ea0ec26c3d8c9 2023-05-15T15:15:42+02:00 Atmospheric iron supply and marine productivity in the glacial North Pacific Ocean F. Burgay A. Spolaor J. Gabrieli G. Cozzi C. Turetta P. Vallelonga C. Barbante 2021-02-01T00:00:00Z https://doi.org/10.5194/cp-17-491-2021 https://doaj.org/article/88f28e96299b416c895ea0ec26c3d8c9 EN eng Copernicus Publications https://cp.copernicus.org/articles/17/491/2021/cp-17-491-2021.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-17-491-2021 1814-9324 1814-9332 https://doaj.org/article/88f28e96299b416c895ea0ec26c3d8c9 Climate of the Past, Vol 17, Pp 491-505 (2021) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2021 ftdoajarticles https://doi.org/10.5194/cp-17-491-2021 2022-12-31T09:44:33Z Iron (Fe) is a key element in the Earth climate system, as it can enhance marine primary productivity in the high-nutrient low-chlorophyll (HNLC) regions where, despite a high concentration of major nutrients, chlorophyll production is low due to iron limitation. Eolian mineral dust represents one of the main Fe sources to the oceans; thus, quantifying its variability over the last glacial cycle is crucial to evaluate its role in strengthening the biological carbon pump. Polar ice cores, which preserve detailed climate records in their stratigraphy, provide a sensitive and continuous archive for reconstructing past eolian Fe fluxes. Here, we show the Northern Hemisphere Fe record retrieved from the NEEM ice core (Greenland), which offers a unique opportunity to reconstruct the past Fe fluxes in a portion of the Arctic over the last 108 kyr. Holocene Fe fluxes (0.042–11.7 ka, 0.5 mg m −2 yr −1 ) at the NEEM site were 4 times lower than the average recorded over the last glacial period (11.7–108 ka, 2.0 mg m −2 yr −1 ), whereas they were greater during the Last Glacial Maximum (LGM; 14.5–26.5 ka, 3.6 mg m −2 yr −1 ) and Marine Isotope Stage 4 (MIS 4; 60–71 ka, 5.8 mg m −2 yr −1 ). Comparing the NEEM Fe record with paleoceanographic records retrieved from the HNLC North Pacific, we found that the coldest periods, characterized by the highest Fe fluxes, were distinguished by low marine primary productivity in the subarctic Pacific Ocean, likely due to the greater sea ice extent and the absence of major nutrients upwelling. This supports the hypothesis that Fe fertilization during colder and dustier periods (i.e., LGM and MIS 4) was more effective in other regions, such as the midlatitude North Pacific, where a closer relationship between marine productivity and the NEEM Fe fluxes was observed. Article in Journal/Newspaper Arctic Greenland ice core Sea ice Subarctic Directory of Open Access Journals: DOAJ Articles Arctic Greenland Pacific Climate of the Past 17 1 491 505 |
institution |
Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
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ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 F. Burgay A. Spolaor J. Gabrieli G. Cozzi C. Turetta P. Vallelonga C. Barbante Atmospheric iron supply and marine productivity in the glacial North Pacific Ocean |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
Iron (Fe) is a key element in the Earth climate system, as it can enhance marine primary productivity in the high-nutrient low-chlorophyll (HNLC) regions where, despite a high concentration of major nutrients, chlorophyll production is low due to iron limitation. Eolian mineral dust represents one of the main Fe sources to the oceans; thus, quantifying its variability over the last glacial cycle is crucial to evaluate its role in strengthening the biological carbon pump. Polar ice cores, which preserve detailed climate records in their stratigraphy, provide a sensitive and continuous archive for reconstructing past eolian Fe fluxes. Here, we show the Northern Hemisphere Fe record retrieved from the NEEM ice core (Greenland), which offers a unique opportunity to reconstruct the past Fe fluxes in a portion of the Arctic over the last 108 kyr. Holocene Fe fluxes (0.042–11.7 ka, 0.5 mg m −2 yr −1 ) at the NEEM site were 4 times lower than the average recorded over the last glacial period (11.7–108 ka, 2.0 mg m −2 yr −1 ), whereas they were greater during the Last Glacial Maximum (LGM; 14.5–26.5 ka, 3.6 mg m −2 yr −1 ) and Marine Isotope Stage 4 (MIS 4; 60–71 ka, 5.8 mg m −2 yr −1 ). Comparing the NEEM Fe record with paleoceanographic records retrieved from the HNLC North Pacific, we found that the coldest periods, characterized by the highest Fe fluxes, were distinguished by low marine primary productivity in the subarctic Pacific Ocean, likely due to the greater sea ice extent and the absence of major nutrients upwelling. This supports the hypothesis that Fe fertilization during colder and dustier periods (i.e., LGM and MIS 4) was more effective in other regions, such as the midlatitude North Pacific, where a closer relationship between marine productivity and the NEEM Fe fluxes was observed. |
format |
Article in Journal/Newspaper |
author |
F. Burgay A. Spolaor J. Gabrieli G. Cozzi C. Turetta P. Vallelonga C. Barbante |
author_facet |
F. Burgay A. Spolaor J. Gabrieli G. Cozzi C. Turetta P. Vallelonga C. Barbante |
author_sort |
F. Burgay |
title |
Atmospheric iron supply and marine productivity in the glacial North Pacific Ocean |
title_short |
Atmospheric iron supply and marine productivity in the glacial North Pacific Ocean |
title_full |
Atmospheric iron supply and marine productivity in the glacial North Pacific Ocean |
title_fullStr |
Atmospheric iron supply and marine productivity in the glacial North Pacific Ocean |
title_full_unstemmed |
Atmospheric iron supply and marine productivity in the glacial North Pacific Ocean |
title_sort |
atmospheric iron supply and marine productivity in the glacial north pacific ocean |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/cp-17-491-2021 https://doaj.org/article/88f28e96299b416c895ea0ec26c3d8c9 |
geographic |
Arctic Greenland Pacific |
geographic_facet |
Arctic Greenland Pacific |
genre |
Arctic Greenland ice core Sea ice Subarctic |
genre_facet |
Arctic Greenland ice core Sea ice Subarctic |
op_source |
Climate of the Past, Vol 17, Pp 491-505 (2021) |
op_relation |
https://cp.copernicus.org/articles/17/491/2021/cp-17-491-2021.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 doi:10.5194/cp-17-491-2021 1814-9324 1814-9332 https://doaj.org/article/88f28e96299b416c895ea0ec26c3d8c9 |
op_doi |
https://doi.org/10.5194/cp-17-491-2021 |
container_title |
Climate of the Past |
container_volume |
17 |
container_issue |
1 |
container_start_page |
491 |
op_container_end_page |
505 |
_version_ |
1766346051920330752 |