Benthic foraminiferal δ¹⁸O and Mg/Ca studies of sediment cores off tropical NW Africa
Benthic foraminiferal d18O and Mg/Ca of sediment cores off tropical NW Africa are used to study the properties of Atlantic central waters during the Last Glacial Maximum (LGM) and Heinrich Stadial 1 (HS1). We combined our core top data with published results to develop a new Mg/Ca-temperature calibr...
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ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.802610 2023-05-15T17:32:00+02:00 Benthic foraminiferal δ¹⁸O and Mg/Ca studies of sediment cores off tropical NW Africa Huang, Enqing Mulitza, Stefan Paul, André Groeneveld, Jeroen Steinke, Stephan Schulz, Michael MEDIAN LATITUDE: 8.915498 * MEDIAN LONGITUDE: -14.921403 * SOUTH-BOUND LATITUDE: 8.875500 * WEST-BOUND LONGITUDE: -14.961000 * NORTH-BOUND LATITUDE: 8.948000 * EAST-BOUND LONGITUDE: -14.889333 * DATE/TIME START: 2005-06-26T10:26:00 * DATE/TIME END: 2005-06-26T23:12:00 2012-11-23 application/zip, 3 datasets https://doi.pangaea.de/10.1594/PANGAEA.802610 https://doi.org/10.1594/PANGAEA.802610 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.802610 https://doi.org/10.1594/PANGAEA.802610 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Huang, Enqing; Mulitza, Stefan; Paul, André; Groeneveld, Jeroen; Steinke, Stephan; Schulz, Michael (2012): Response of eastern tropical Atlantic central waters to Atlantic meridional overturning circulation changes during the Last Glacial Maximum and Heinrich Stadial 1. Paleoceanography, 27, https://doi.org/10.1029/2012PA002294 Center for Marine Environmental Sciences MARUM Dataset 2012 ftpangaea https://doi.org/10.1594/PANGAEA.802610 https://doi.org/10.1029/2012PA002294 2023-01-20T07:32:48Z Benthic foraminiferal d18O and Mg/Ca of sediment cores off tropical NW Africa are used to study the properties of Atlantic central waters during the Last Glacial Maximum (LGM) and Heinrich Stadial 1 (HS1). We combined our core top data with published results to develop a new Mg/Ca-temperature calibration for Planulina ariminensis, which shows a Mg/Ca-temperature sensitivity of 0.19 mmol/mol per °C. Estimates of the LGM and HS1 thermocline temperatures are comparable to the present-day values between 200 and 400 m water depth, but were 1.2-1.5°C warmer at 550-570 m depth. The HS1 thermocline waters (200-570 m depth) did not show any warming relative to the LGM. This is in contrast to previous climate model studies, which concluded that tropical Atlantic thermocline waters warmed significantly when Atlantic meridional overturning circulation was reduced. However, our results suggest that thermocline temperatures of the northeastern tropical Atlantic show no pronounced sensitivity to changes in the thermohaline circulation during glacial periods. In contrast, we find a significant increase in thermocline-water salinity during the LGM (200-550 m depth) and HS1 (200-400 m depth) with respect to the present-day, which we relate to changes in the wind-driven circulation. We infer that the LGM thermocline (200-550 m depth) and the HS1 upper thermocline (200-400 m depth) in the northeastern tropical Atlantic was ventilated by surface waters from the North Atlantic rather than the southern-sourced waters. This suggests that the frontal zone between the modern South Atlantic and North Atlantic Central Waters was probably shifted southward during the LGM and HS1. Dataset North Atlantic PANGAEA - Data Publisher for Earth & Environmental Science ENVELOPE(-14.961000,-14.889333,8.948000,8.875500) |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
Center for Marine Environmental Sciences MARUM |
spellingShingle |
Center for Marine Environmental Sciences MARUM Huang, Enqing Mulitza, Stefan Paul, André Groeneveld, Jeroen Steinke, Stephan Schulz, Michael Benthic foraminiferal δ¹⁸O and Mg/Ca studies of sediment cores off tropical NW Africa |
topic_facet |
Center for Marine Environmental Sciences MARUM |
description |
Benthic foraminiferal d18O and Mg/Ca of sediment cores off tropical NW Africa are used to study the properties of Atlantic central waters during the Last Glacial Maximum (LGM) and Heinrich Stadial 1 (HS1). We combined our core top data with published results to develop a new Mg/Ca-temperature calibration for Planulina ariminensis, which shows a Mg/Ca-temperature sensitivity of 0.19 mmol/mol per °C. Estimates of the LGM and HS1 thermocline temperatures are comparable to the present-day values between 200 and 400 m water depth, but were 1.2-1.5°C warmer at 550-570 m depth. The HS1 thermocline waters (200-570 m depth) did not show any warming relative to the LGM. This is in contrast to previous climate model studies, which concluded that tropical Atlantic thermocline waters warmed significantly when Atlantic meridional overturning circulation was reduced. However, our results suggest that thermocline temperatures of the northeastern tropical Atlantic show no pronounced sensitivity to changes in the thermohaline circulation during glacial periods. In contrast, we find a significant increase in thermocline-water salinity during the LGM (200-550 m depth) and HS1 (200-400 m depth) with respect to the present-day, which we relate to changes in the wind-driven circulation. We infer that the LGM thermocline (200-550 m depth) and the HS1 upper thermocline (200-400 m depth) in the northeastern tropical Atlantic was ventilated by surface waters from the North Atlantic rather than the southern-sourced waters. This suggests that the frontal zone between the modern South Atlantic and North Atlantic Central Waters was probably shifted southward during the LGM and HS1. |
format |
Dataset |
author |
Huang, Enqing Mulitza, Stefan Paul, André Groeneveld, Jeroen Steinke, Stephan Schulz, Michael |
author_facet |
Huang, Enqing Mulitza, Stefan Paul, André Groeneveld, Jeroen Steinke, Stephan Schulz, Michael |
author_sort |
Huang, Enqing |
title |
Benthic foraminiferal δ¹⁸O and Mg/Ca studies of sediment cores off tropical NW Africa |
title_short |
Benthic foraminiferal δ¹⁸O and Mg/Ca studies of sediment cores off tropical NW Africa |
title_full |
Benthic foraminiferal δ¹⁸O and Mg/Ca studies of sediment cores off tropical NW Africa |
title_fullStr |
Benthic foraminiferal δ¹⁸O and Mg/Ca studies of sediment cores off tropical NW Africa |
title_full_unstemmed |
Benthic foraminiferal δ¹⁸O and Mg/Ca studies of sediment cores off tropical NW Africa |
title_sort |
benthic foraminiferal δ¹⁸o and mg/ca studies of sediment cores off tropical nw africa |
publisher |
PANGAEA |
publishDate |
2012 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.802610 https://doi.org/10.1594/PANGAEA.802610 |
op_coverage |
MEDIAN LATITUDE: 8.915498 * MEDIAN LONGITUDE: -14.921403 * SOUTH-BOUND LATITUDE: 8.875500 * WEST-BOUND LONGITUDE: -14.961000 * NORTH-BOUND LATITUDE: 8.948000 * EAST-BOUND LONGITUDE: -14.889333 * DATE/TIME START: 2005-06-26T10:26:00 * DATE/TIME END: 2005-06-26T23:12:00 |
long_lat |
ENVELOPE(-14.961000,-14.889333,8.948000,8.875500) |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Supplement to: Huang, Enqing; Mulitza, Stefan; Paul, André; Groeneveld, Jeroen; Steinke, Stephan; Schulz, Michael (2012): Response of eastern tropical Atlantic central waters to Atlantic meridional overturning circulation changes during the Last Glacial Maximum and Heinrich Stadial 1. Paleoceanography, 27, https://doi.org/10.1029/2012PA002294 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.802610 https://doi.org/10.1594/PANGAEA.802610 |
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.802610 https://doi.org/10.1029/2012PA002294 |
_version_ |
1766129902165164032 |