A multi-decadal record of oceanographic changes of the past ~165 years (1850-2015 AD) from Northwest of Iceland
Extending oceanographic data beyond the instrumental period is highly needed to better characterize and understand multi-decadal to centennial natural ocean variability. Here, a stable isotope record at unprecedented temporal resolution (1 to 2 years) from a new marine core retrieved off western Nor...
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ftdatacite:10.17863/cam.57956 2023-05-15T15:17:29+02:00 A multi-decadal record of oceanographic changes of the past ~165 years (1850-2015 AD) from Northwest of Iceland Simon, Margit H. Muschitiello, Francesco Tisserand, Amandine A. Olsen, Are Moros, Matthias Perner, Kerstin Bårdsnes, Siv Tone Dokken, Trond M. Jansen, Eystein 2020 https://dx.doi.org/10.17863/cam.57956 https://www.repository.cam.ac.uk/handle/1810/310865 unknown Apollo - University of Cambridge Repository Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 CC-BY Research Article Ecology and environmental sciences Earth sciences Physical sciences FOS Physical sciences Text Article article-journal ScholarlyArticle 2020 ftdatacite https://doi.org/10.17863/cam.57956 2021-11-05T12:55:41Z Extending oceanographic data beyond the instrumental period is highly needed to better characterize and understand multi-decadal to centennial natural ocean variability. Here, a stable isotope record at unprecedented temporal resolution (1 to 2 years) from a new marine core retrieved off western North Iceland is presented. We aim to better constrain the variability of subsurface, Atlantic-derived Subpolar Mode Water (SPMW), using near surface-dwelling planktic foraminifera and Arctic Intermediate Water (AIW) mass changes using benthic foraminifera over the last ~165 years. The reconstruction overlaps in time with instrumental observations and a direct comparison reveals that the δ18O record of Neogloboquadrina pachyderma is reliably representing temperature fluctuations in the SPMWs. Trends in the N. pachyderma δ13C record match the measured phosphate concentration in the upper 200 m on the North Icelandic Shelf well. Near surface-dwelling foraminifera trace anthropogenic CO2 in the Iceland Sea by ~ 1950 ± 8, however, a reduced amplitude shift in the Marine Suess effect is identified. We argue that this is caused by a contemporary ongoing increase in marine primary productivity in the upper ocean due to enhanced Greenland’s freshwater discharge that has contributed to a nutrient-driven fertilization since the 1940s/50s (Perner et al., 2019). Multi-decadal variability is detected. We find that the 16-year periodicity evident in SPMW and AIWs based on the δ18O of N. pachyderma and M. barleeanum is a signal of SST anomalies propagated into the Nordic Seas via the Atlantic inflow branches around Iceland. Spectral analyses of the planktic foraminiferal δ13C signal indicate intermittent 30-year cycles that are likely reflecting the ocean response to atmospheric variability, presumably the East Atlantic Pattern. A long-term trend in benthic δ18O suggests that Atlantic-derived waters are expanding their core within the water column from the subsurface into deeper intermediate depths towards the present day. This is a result of increased transport by the North Icelandic Irminger Current to the North Iceland Shelf over the historical era. Text Arctic Foraminifera* Iceland Neogloboquadrina pachyderma Nordic Seas North Icelandic Irminger Current DataCite Metadata Store (German National Library of Science and Technology) Arctic |
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language |
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topic |
Research Article Ecology and environmental sciences Earth sciences Physical sciences FOS Physical sciences |
spellingShingle |
Research Article Ecology and environmental sciences Earth sciences Physical sciences FOS Physical sciences Simon, Margit H. Muschitiello, Francesco Tisserand, Amandine A. Olsen, Are Moros, Matthias Perner, Kerstin Bårdsnes, Siv Tone Dokken, Trond M. Jansen, Eystein A multi-decadal record of oceanographic changes of the past ~165 years (1850-2015 AD) from Northwest of Iceland |
topic_facet |
Research Article Ecology and environmental sciences Earth sciences Physical sciences FOS Physical sciences |
description |
Extending oceanographic data beyond the instrumental period is highly needed to better characterize and understand multi-decadal to centennial natural ocean variability. Here, a stable isotope record at unprecedented temporal resolution (1 to 2 years) from a new marine core retrieved off western North Iceland is presented. We aim to better constrain the variability of subsurface, Atlantic-derived Subpolar Mode Water (SPMW), using near surface-dwelling planktic foraminifera and Arctic Intermediate Water (AIW) mass changes using benthic foraminifera over the last ~165 years. The reconstruction overlaps in time with instrumental observations and a direct comparison reveals that the δ18O record of Neogloboquadrina pachyderma is reliably representing temperature fluctuations in the SPMWs. Trends in the N. pachyderma δ13C record match the measured phosphate concentration in the upper 200 m on the North Icelandic Shelf well. Near surface-dwelling foraminifera trace anthropogenic CO2 in the Iceland Sea by ~ 1950 ± 8, however, a reduced amplitude shift in the Marine Suess effect is identified. We argue that this is caused by a contemporary ongoing increase in marine primary productivity in the upper ocean due to enhanced Greenland’s freshwater discharge that has contributed to a nutrient-driven fertilization since the 1940s/50s (Perner et al., 2019). Multi-decadal variability is detected. We find that the 16-year periodicity evident in SPMW and AIWs based on the δ18O of N. pachyderma and M. barleeanum is a signal of SST anomalies propagated into the Nordic Seas via the Atlantic inflow branches around Iceland. Spectral analyses of the planktic foraminiferal δ13C signal indicate intermittent 30-year cycles that are likely reflecting the ocean response to atmospheric variability, presumably the East Atlantic Pattern. A long-term trend in benthic δ18O suggests that Atlantic-derived waters are expanding their core within the water column from the subsurface into deeper intermediate depths towards the present day. This is a result of increased transport by the North Icelandic Irminger Current to the North Iceland Shelf over the historical era. |
format |
Text |
author |
Simon, Margit H. Muschitiello, Francesco Tisserand, Amandine A. Olsen, Are Moros, Matthias Perner, Kerstin Bårdsnes, Siv Tone Dokken, Trond M. Jansen, Eystein |
author_facet |
Simon, Margit H. Muschitiello, Francesco Tisserand, Amandine A. Olsen, Are Moros, Matthias Perner, Kerstin Bårdsnes, Siv Tone Dokken, Trond M. Jansen, Eystein |
author_sort |
Simon, Margit H. |
title |
A multi-decadal record of oceanographic changes of the past ~165 years (1850-2015 AD) from Northwest of Iceland |
title_short |
A multi-decadal record of oceanographic changes of the past ~165 years (1850-2015 AD) from Northwest of Iceland |
title_full |
A multi-decadal record of oceanographic changes of the past ~165 years (1850-2015 AD) from Northwest of Iceland |
title_fullStr |
A multi-decadal record of oceanographic changes of the past ~165 years (1850-2015 AD) from Northwest of Iceland |
title_full_unstemmed |
A multi-decadal record of oceanographic changes of the past ~165 years (1850-2015 AD) from Northwest of Iceland |
title_sort |
multi-decadal record of oceanographic changes of the past ~165 years (1850-2015 ad) from northwest of iceland |
publisher |
Apollo - University of Cambridge Repository |
publishDate |
2020 |
url |
https://dx.doi.org/10.17863/cam.57956 https://www.repository.cam.ac.uk/handle/1810/310865 |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Foraminifera* Iceland Neogloboquadrina pachyderma Nordic Seas North Icelandic Irminger Current |
genre_facet |
Arctic Foraminifera* Iceland Neogloboquadrina pachyderma Nordic Seas North Icelandic Irminger Current |
op_rights |
Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/legalcode cc-by-4.0 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.17863/cam.57956 |
_version_ |
1766347725237911552 |