Log-ratio of silica to aluminium counts (ln(Si/Al)) from ODP site 108-658
Growing evidence suggests that the low atmospheric CO2 concentration of the ice ages resulted from enhanced storage of CO2 in the ocean interior, largely as a result of changes in the Southern Ocean1. Early in the most recent deglaciation, a reduction in North Atlantic overturning circulation seems...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.810016 2023-05-15T13:42:11+02:00 Log-ratio of silica to aluminium counts (ln(Si/Al)) from ODP site 108-658 Meckler, Anna Nele Sigman, Daniel M Gibson, Kelly A Francois, Roger Martínez‐García, Alfredo Jaccard, Samuel L Röhl, Ursula Peterson, Larry C Tiedemann, Ralf Haug, Gerald H MEDIAN LATITUDE: 20.082733 * MEDIAN LONGITUDE: -19.223100 * SOUTH-BOUND LATITUDE: 18.083333 * WEST-BOUND LONGITUDE: -21.150000 * NORTH-BOUND LATITUDE: 20.749200 * EAST-BOUND LONGITUDE: -18.580800 * DATE/TIME START: 1986-03-04T00:00:00 * DATE/TIME END: 1986-03-08T16:00:00 2013-04-09 application/zip, 4 datasets https://doi.pangaea.de/10.1594/PANGAEA.810016 https://doi.org/10.1594/PANGAEA.810016 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.810016 https://doi.org/10.1594/PANGAEA.810016 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Meckler, Anna Nele; Sigman, Daniel M; Gibson, Kelly A; Francois, Roger; Martínez‐García, Alfredo; Jaccard, Samuel L; Röhl, Ursula; Peterson, Larry C; Tiedemann, Ralf; Haug, Gerald H (2013): Deglacial pulses of deep-ocean silicate into the subtropical North Atlantic Ocean. Nature, 495(7442), 495-498, https://doi.org/10.1038/nature12006 Ocean Drilling Program ODP Dataset 2013 ftpangaea https://doi.org/10.1594/PANGAEA.810016 https://doi.org/10.1038/nature12006 2023-01-20T07:32:57Z Growing evidence suggests that the low atmospheric CO2 concentration of the ice ages resulted from enhanced storage of CO2 in the ocean interior, largely as a result of changes in the Southern Ocean1. Early in the most recent deglaciation, a reduction in North Atlantic overturning circulation seems to have driven CO2 release from the Southern Ocean**2, 3, 4, 5, but the mechanism connecting the North Atlantic and the Southern Ocean remains unclear. Biogenic opal export in the low-latitude ocean relies on silicate from the underlying thermocline, the concentration of which is affected by the circulation of the ocean interior. Here we report a record of biogenic opal export from a coastal upwelling system off the coast of northwest Africa that shows pronounced opal maxima during each glacial termination over the past 550,000 years. These opal peaks are consistent with a strong deglacial reduction in the formation of silicate-poor glacial North Atlantic intermediate water**2 (GNAIW). The loss of GNAIW allowed mixing with underlying silicate-rich deep water to increase the silicate supply to the surface ocean. An increase in westerly-wind-driven upwelling in the Southern Ocean in response to the North Atlantic change has been proposed to drive the deglacial rise in atmospheric CO2 (refs 3, 4). However, such a circulation change would have accelerated the formation of Antarctic intermediate water and sub-Antarctic mode water, which today have as little silicate as North Atlantic Deep Water and would have thus maintained low silicate concentrations in the Atlantic thermocline. The deglacial opal maxima reported here suggest an alternative mechanism for the deglacial CO2 release**5, 6. Just as the reduction in GNAIW led to upward silicate transport, it should also have allowed the downward mixing of warm, low-density surface water to reach into the deep ocean. The resulting decrease in the density of the deep Atlantic relative to the Southern Ocean surface promoted Antarctic overturning, which released CO2 to the ... Dataset Antarc* Antarctic North Atlantic Deep Water North Atlantic Southern Ocean PANGAEA - Data Publisher for Earth & Environmental Science Antarctic Southern Ocean ENVELOPE(-21.150000,-18.580800,20.749200,18.083333) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
Ocean Drilling Program ODP |
spellingShingle |
Ocean Drilling Program ODP Meckler, Anna Nele Sigman, Daniel M Gibson, Kelly A Francois, Roger Martínez‐García, Alfredo Jaccard, Samuel L Röhl, Ursula Peterson, Larry C Tiedemann, Ralf Haug, Gerald H Log-ratio of silica to aluminium counts (ln(Si/Al)) from ODP site 108-658 |
topic_facet |
Ocean Drilling Program ODP |
description |
Growing evidence suggests that the low atmospheric CO2 concentration of the ice ages resulted from enhanced storage of CO2 in the ocean interior, largely as a result of changes in the Southern Ocean1. Early in the most recent deglaciation, a reduction in North Atlantic overturning circulation seems to have driven CO2 release from the Southern Ocean**2, 3, 4, 5, but the mechanism connecting the North Atlantic and the Southern Ocean remains unclear. Biogenic opal export in the low-latitude ocean relies on silicate from the underlying thermocline, the concentration of which is affected by the circulation of the ocean interior. Here we report a record of biogenic opal export from a coastal upwelling system off the coast of northwest Africa that shows pronounced opal maxima during each glacial termination over the past 550,000 years. These opal peaks are consistent with a strong deglacial reduction in the formation of silicate-poor glacial North Atlantic intermediate water**2 (GNAIW). The loss of GNAIW allowed mixing with underlying silicate-rich deep water to increase the silicate supply to the surface ocean. An increase in westerly-wind-driven upwelling in the Southern Ocean in response to the North Atlantic change has been proposed to drive the deglacial rise in atmospheric CO2 (refs 3, 4). However, such a circulation change would have accelerated the formation of Antarctic intermediate water and sub-Antarctic mode water, which today have as little silicate as North Atlantic Deep Water and would have thus maintained low silicate concentrations in the Atlantic thermocline. The deglacial opal maxima reported here suggest an alternative mechanism for the deglacial CO2 release**5, 6. Just as the reduction in GNAIW led to upward silicate transport, it should also have allowed the downward mixing of warm, low-density surface water to reach into the deep ocean. The resulting decrease in the density of the deep Atlantic relative to the Southern Ocean surface promoted Antarctic overturning, which released CO2 to the ... |
format |
Dataset |
author |
Meckler, Anna Nele Sigman, Daniel M Gibson, Kelly A Francois, Roger Martínez‐García, Alfredo Jaccard, Samuel L Röhl, Ursula Peterson, Larry C Tiedemann, Ralf Haug, Gerald H |
author_facet |
Meckler, Anna Nele Sigman, Daniel M Gibson, Kelly A Francois, Roger Martínez‐García, Alfredo Jaccard, Samuel L Röhl, Ursula Peterson, Larry C Tiedemann, Ralf Haug, Gerald H |
author_sort |
Meckler, Anna Nele |
title |
Log-ratio of silica to aluminium counts (ln(Si/Al)) from ODP site 108-658 |
title_short |
Log-ratio of silica to aluminium counts (ln(Si/Al)) from ODP site 108-658 |
title_full |
Log-ratio of silica to aluminium counts (ln(Si/Al)) from ODP site 108-658 |
title_fullStr |
Log-ratio of silica to aluminium counts (ln(Si/Al)) from ODP site 108-658 |
title_full_unstemmed |
Log-ratio of silica to aluminium counts (ln(Si/Al)) from ODP site 108-658 |
title_sort |
log-ratio of silica to aluminium counts (ln(si/al)) from odp site 108-658 |
publisher |
PANGAEA |
publishDate |
2013 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.810016 https://doi.org/10.1594/PANGAEA.810016 |
op_coverage |
MEDIAN LATITUDE: 20.082733 * MEDIAN LONGITUDE: -19.223100 * SOUTH-BOUND LATITUDE: 18.083333 * WEST-BOUND LONGITUDE: -21.150000 * NORTH-BOUND LATITUDE: 20.749200 * EAST-BOUND LONGITUDE: -18.580800 * DATE/TIME START: 1986-03-04T00:00:00 * DATE/TIME END: 1986-03-08T16:00:00 |
long_lat |
ENVELOPE(-21.150000,-18.580800,20.749200,18.083333) |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic North Atlantic Deep Water North Atlantic Southern Ocean |
genre_facet |
Antarc* Antarctic North Atlantic Deep Water North Atlantic Southern Ocean |
op_source |
Supplement to: Meckler, Anna Nele; Sigman, Daniel M; Gibson, Kelly A; Francois, Roger; Martínez‐García, Alfredo; Jaccard, Samuel L; Röhl, Ursula; Peterson, Larry C; Tiedemann, Ralf; Haug, Gerald H (2013): Deglacial pulses of deep-ocean silicate into the subtropical North Atlantic Ocean. Nature, 495(7442), 495-498, https://doi.org/10.1038/nature12006 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.810016 https://doi.org/10.1594/PANGAEA.810016 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.810016 https://doi.org/10.1038/nature12006 |
_version_ |
1766164436343586816 |