Stable isotope record of planktonic foraminifera of the South Atlantic
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| Main Authors: | , , , , , , , , , , , , , |
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| Format: | Dataset Open Access |
| Language: | en |
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PANGAEA
1996
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| _version_ | 1867170457848905728 |
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| author | Wefer, Gerold Berger, Wolfgang H Bickert, Torsten Donner, Barbara Fischer, Gerhard Kemle-von Mücke, Sylvia Pätzold, Jürgen Meinecke, Gerrit Müller, Peter J Mulitza, Stefan Niebler, Hans-Stefan Schmidt, Heike Schneider, Ralph R Segl, Monika |
| author_facet | Wefer, Gerold Berger, Wolfgang H Bickert, Torsten Donner, Barbara Fischer, Gerhard Kemle-von Mücke, Sylvia Pätzold, Jürgen Meinecke, Gerrit Müller, Peter J Mulitza, Stefan Niebler, Hans-Stefan Schmidt, Heike Schneider, Ralph R Segl, Monika |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | The central problem of late Quaternary circulation in the South Atlantic is its role in transfer of heat to the North Atlantic, as this modifies amplitude, and perhaps phase, of glacialinterglacial fluctuations. Here we attempt to define the problem and establish ways to attack it. We identify several crucial elements in the dynamics of heat export: (1) warm-water pile-up (and lack thereof) in the Western equatorial Atlantic, (2) general spin-up (or spin-down) of central gyre, tied to SE trades, (3) opening and closing of Cape Valve (Agulhas retroflection), (4) deepwater E-W asymmetry. Means for reconstruction are biogeography, stable isotopes, and productivity proxies. Main results concern overall glacial-interglacial contrast (less pile-up, more spin-up, Cape Valve closed, less NADW during glacial time), dominance of precessional signal in tropics, phase shifts in precessional response. To generate working hypotheses about the dynamics of surface water circulation in the South Atlantic we employ Croll's paradigm that glacial - interglacial fluctuations are analogous to seasonal fluctuations. Our general picture for the last 300 kyrs is that, as concerns the South Atlantic, intensity of surface water (heat) transport depends on the strength of the SE trades. From various lines of evidence it appears that strenger SE trades appeared during glacials and cold substages during interglacials, analogous to conditions in southern winter (August). |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_738529 |
| institution | PANGAEA |
| language | en |
| publishDate | 1996 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Stable isotope record of planktonic foraminifera of the South Atlantic Wefer, Gerold Berger, Wolfgang H Bickert, Torsten Donner, Barbara Fischer, Gerhard Kemle-von Mücke, Sylvia Pätzold, Jürgen Meinecke, Gerrit Müller, Peter J Mulitza, Stefan Niebler, Hans-Stefan Schmidt, Heike Schneider, Ralph R Segl, Monika Amazon Fan; Angola Basin; Equatorial Atlantic; GeoB; GeoB1028-4; GeoB1028-5; GeoB1031-1; GeoB1031-4; GeoB1032-2; GeoB1032-3; GeoB1105-3; GeoB1105-4; GeoB1112-3; GeoB1112-4; GeoB1220-1; GeoB1220-2; GeoB1413-1; GeoB1413-2; GeoB1413-4; GeoB1523-1; GeoB1523-2; Geosciences, University of Bremen; Giant box corer; GKG; Gravity corer (Kiel type); M12/1; M16/1; M16/2; M6/6; M9/4; Meteor (1986); MUC; MultiCorer; SFB261; SL; South Atlantic in Late Quaternary: Reconstruction of Budget and Currents; Walvis Ridge; Walvis Ridge, Southeast Atlantic Ocean; West Angola Basin The central problem of late Quaternary circulation in the South Atlantic is its role in transfer of heat to the North Atlantic, as this modifies amplitude, and perhaps phase, of glacialinterglacial fluctuations. Here we attempt to define the problem and establish ways to attack it. We identify several crucial elements in the dynamics of heat export: (1) warm-water pile-up (and lack thereof) in the Western equatorial Atlantic, (2) general spin-up (or spin-down) of central gyre, tied to SE trades, (3) opening and closing of Cape Valve (Agulhas retroflection), (4) deepwater E-W asymmetry. Means for reconstruction are biogeography, stable isotopes, and productivity proxies. Main results concern overall glacial-interglacial contrast (less pile-up, more spin-up, Cape Valve closed, less NADW during glacial time), dominance of precessional signal in tropics, phase shifts in precessional response. To generate working hypotheses about the dynamics of surface water circulation in the South Atlantic we employ Croll's paradigm that glacial - interglacial fluctuations are analogous to seasonal fluctuations. Our general picture for the last 300 kyrs is that, as concerns the South Atlantic, intensity of surface water (heat) transport depends on the strength of the SE trades. From various lines of evidence it appears that strenger SE trades appeared during glacials and cold substages during interglacials, analogous to conditions in southern winter (August). |
| title | Stable isotope record of planktonic foraminifera of the South Atlantic |
| topic | Amazon Fan; Angola Basin; Equatorial Atlantic; GeoB; GeoB1028-4; GeoB1028-5; GeoB1031-1; GeoB1031-4; GeoB1032-2; GeoB1032-3; GeoB1105-3; GeoB1105-4; GeoB1112-3; GeoB1112-4; GeoB1220-1; GeoB1220-2; GeoB1413-1; GeoB1413-2; GeoB1413-4; GeoB1523-1; GeoB1523-2; Geosciences, University of Bremen; Giant box corer; GKG; Gravity corer (Kiel type); M12/1; M16/1; M16/2; M6/6; M9/4; Meteor (1986); MUC; MultiCorer; SFB261; SL; South Atlantic in Late Quaternary: Reconstruction of Budget and Currents; Walvis Ridge; Walvis Ridge, Southeast Atlantic Ocean; West Angola Basin |
| url | https://doi.org/10.1594/PANGAEA.738529 |