Nutrient regime and upwelling in the northern Benguela since the middle Holocene in a global context – a multi-proxy approach
The last 5500 years of climate change and environmental response in the northern Benguela Coastal Upwelling are reconstructed by means of three sediment cores from the inner shelf off central Namibia. The study is based on nutrient (δ15N, δ13C) and productivity proxies (accumulation rates of total o...
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ftleibnizopen:oai:oai.leibnizopen.de:LNlMoYoBbHMkKcxzJmoE 2023-10-09T21:53:35+02:00 Nutrient regime and upwelling in the northern Benguela since the middle Holocene in a global context – a multi-proxy approach Meisel, Sandra Emeis, Kay-Christian Struck, Ulrich Kristen, Iris 2011 https://repository.publisso.de/resource/frl:6406901 https://doi.org/10.1002/mmng.201100006 eng eng https://creativecommons.org/licenses/by/3.0/ Fossil record, 14(2):171-193 NADW Benguela Upwelling climate forcing Agulhas Water alkenone temperatures nitrogen isotopes oxygen isotopes 2011 ftleibnizopen https://doi.org/10.1002/mmng.201100006 2023-09-17T23:26:44Z The last 5500 years of climate change and environmental response in the northern Benguela Coastal Upwelling are reconstructed by means of three sediment cores from the inner shelf off central Namibia. The study is based on nutrient (δ15N, δ13C) and productivity proxies (accumulation rates of total organic carbon; ARTOC). Reconstructed sea surface temperatures (alkenone-derived SST) and temperatures at subsurface depths (Tδ18O; based on tests of planktonic foraminifers) reflect the physical boundary conditions. The selection of proxy indicators proved a valuable basis for robust palaeo-climatic reconstructions, with the resolution ranging from multi-decadal (NAM1) over centennial (core 178) to millennial scale (core 226620). The northern Benguela experienced pronounced and rapid perturbation during the middle and late Holocene, and apparently, not all are purely local in character. In fact, numerous correlations with records from the adjacent South African subcontinent and the northern hemisphere testify to global climatic teleconnections. The Holocene Hypsithermal, for instance, is just as evident as the Little Ice Age (LIA) and the Roman Warm Period. The marked SST-rise associated with the latter is substantiated by other marine and terrestrial data from the South African realm. The LIA (at least its early stages) manifests itself in intensified winds and upwelling, which accords with increased rainfall receipts above the continental interior. It appears that climate signals are transferred both via the atmosphere and ocean. The combined analysis of SST and Tδ18O proved a useful tool in order to differentiate between both pathways. SSTs are primarily controlled by the intensity of atmospheric circulation features, reflecting changes of upwelling-favourable winds. Tδ18O records the temperature of the source water and often correlates with global ocean conveyor speed due to varying inputs of warm Agulhas Water. It seems as though conveyor slowdown or acceleration not only affected the temperature of the source ... Other/Unknown Material NADW LeibnizOpen (The Leibniz Association) Fossil Record 14 2 171 193 |
institution |
Open Polar |
collection |
LeibnizOpen (The Leibniz Association) |
op_collection_id |
ftleibnizopen |
language |
English |
topic |
NADW Benguela Upwelling climate forcing Agulhas Water alkenone temperatures nitrogen isotopes oxygen isotopes |
spellingShingle |
NADW Benguela Upwelling climate forcing Agulhas Water alkenone temperatures nitrogen isotopes oxygen isotopes Meisel, Sandra Emeis, Kay-Christian Struck, Ulrich Kristen, Iris Nutrient regime and upwelling in the northern Benguela since the middle Holocene in a global context – a multi-proxy approach |
topic_facet |
NADW Benguela Upwelling climate forcing Agulhas Water alkenone temperatures nitrogen isotopes oxygen isotopes |
description |
The last 5500 years of climate change and environmental response in the northern Benguela Coastal Upwelling are reconstructed by means of three sediment cores from the inner shelf off central Namibia. The study is based on nutrient (δ15N, δ13C) and productivity proxies (accumulation rates of total organic carbon; ARTOC). Reconstructed sea surface temperatures (alkenone-derived SST) and temperatures at subsurface depths (Tδ18O; based on tests of planktonic foraminifers) reflect the physical boundary conditions. The selection of proxy indicators proved a valuable basis for robust palaeo-climatic reconstructions, with the resolution ranging from multi-decadal (NAM1) over centennial (core 178) to millennial scale (core 226620). The northern Benguela experienced pronounced and rapid perturbation during the middle and late Holocene, and apparently, not all are purely local in character. In fact, numerous correlations with records from the adjacent South African subcontinent and the northern hemisphere testify to global climatic teleconnections. The Holocene Hypsithermal, for instance, is just as evident as the Little Ice Age (LIA) and the Roman Warm Period. The marked SST-rise associated with the latter is substantiated by other marine and terrestrial data from the South African realm. The LIA (at least its early stages) manifests itself in intensified winds and upwelling, which accords with increased rainfall receipts above the continental interior. It appears that climate signals are transferred both via the atmosphere and ocean. The combined analysis of SST and Tδ18O proved a useful tool in order to differentiate between both pathways. SSTs are primarily controlled by the intensity of atmospheric circulation features, reflecting changes of upwelling-favourable winds. Tδ18O records the temperature of the source water and often correlates with global ocean conveyor speed due to varying inputs of warm Agulhas Water. It seems as though conveyor slowdown or acceleration not only affected the temperature of the source ... |
author |
Meisel, Sandra Emeis, Kay-Christian Struck, Ulrich Kristen, Iris |
author_facet |
Meisel, Sandra Emeis, Kay-Christian Struck, Ulrich Kristen, Iris |
author_sort |
Meisel, Sandra |
title |
Nutrient regime and upwelling in the northern Benguela since the middle Holocene in a global context – a multi-proxy approach |
title_short |
Nutrient regime and upwelling in the northern Benguela since the middle Holocene in a global context – a multi-proxy approach |
title_full |
Nutrient regime and upwelling in the northern Benguela since the middle Holocene in a global context – a multi-proxy approach |
title_fullStr |
Nutrient regime and upwelling in the northern Benguela since the middle Holocene in a global context – a multi-proxy approach |
title_full_unstemmed |
Nutrient regime and upwelling in the northern Benguela since the middle Holocene in a global context – a multi-proxy approach |
title_sort |
nutrient regime and upwelling in the northern benguela since the middle holocene in a global context – a multi-proxy approach |
publishDate |
2011 |
url |
https://repository.publisso.de/resource/frl:6406901 https://doi.org/10.1002/mmng.201100006 |
genre |
NADW |
genre_facet |
NADW |
op_source |
Fossil record, 14(2):171-193 |
op_rights |
https://creativecommons.org/licenses/by/3.0/ |
op_doi |
https://doi.org/10.1002/mmng.201100006 |
container_title |
Fossil Record |
container_volume |
14 |
container_issue |
2 |
container_start_page |
171 |
op_container_end_page |
193 |
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1779316884968046592 |