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| Format: | Dataset Open Access |
| Sprache: | en |
| Veröffentlicht: |
PANGAEA
2016
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| Schlagworte: | |
| Online-Zugang: | https://doi.org/10.1594/PANGAEA.872152 |
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| _version_ | 1867168569607847936 |
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| author | Lessa, Douglas Villela de Oliveira Venancio, Igor Martins Santos, Thiago Pereira dos Belem, Andre L Turcq, Bruno Jean Sifeddine, Abdelfettah Albuquerque, Ana Luiza Spadano |
| author_facet | Lessa, Douglas Villela de Oliveira Venancio, Igor Martins Santos, Thiago Pereira dos Belem, Andre L Turcq, Bruno Jean Sifeddine, Abdelfettah Albuquerque, Ana Luiza Spadano |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | The Brazil Current (BC) is a relevant feature in the Atlantic Meridional Overturning Circulation (AMOC). Its behavior during slowdown or intense AMOC remains poorly known because of the lack of paleoceanographic records, especially for the Holocene. Here, we investigate changes in a western boundary upwelling system (Cabo Frio, off Southeastern Brazil) which are driven by variations in the BC and NE winds during the last 9 kyr. To assess the variability of the BC, we used d18O, Mg/Ca, and assemblages of planktonic foraminifera. Our results indicate five oceanographic phases during the last 9 kyr. During Phase I (from 9.0 to 7.0 cal kyr BP), the BC diverged offshore from the modern upwelling area because of the low sea level, increasing the influence of shelf waters and coastal upwelling plumes on foraminifera assemblages. Phase II (7.0-5.0 kyr BP) was marked by the approach of the internal front of the BC with low intensity and episodes of strong productivity that were linked primarily to the upwelling of the South Atlantic Central Water (SACW) and/or Subpolar Shelf Waters (SPSWs) (cold). Phase III (5.0-3.5 kyr BP) was a transition, marking a large oceanographic and climatic change from the weakening of the AMOC. The internal front of the BC became warm and subsurface SACW upwelling was stronger. In Phase IV (3.5-2.5 kyr BP), the BC acquired its modern dynamics, but weak NE winds weakened the SACW's contribution to upwelling events. Finally, in Phase V (last 2.5 kyr BP), the NE winds reintensified, promoting frequent episodes of upwelling and intrusion by SPSWs during the Medieval Climate Anomaly. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_872152 |
| institution | PANGAEA |
| language | en |
| publishDate | 2016 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Planktonic foraminifera, stable isotopes and Mg/Ca ratio from Cabo Frio (Brazil) sediment cores CF10-01B and CF10-09A Lessa, Douglas Villela de Oliveira Venancio, Igor Martins Santos, Thiago Pereira dos Belem, Andre L Turcq, Bruno Jean Sifeddine, Abdelfettah Albuquerque, Ana Luiza Spadano The Brazil Current (BC) is a relevant feature in the Atlantic Meridional Overturning Circulation (AMOC). Its behavior during slowdown or intense AMOC remains poorly known because of the lack of paleoceanographic records, especially for the Holocene. Here, we investigate changes in a western boundary upwelling system (Cabo Frio, off Southeastern Brazil) which are driven by variations in the BC and NE winds during the last 9 kyr. To assess the variability of the BC, we used d18O, Mg/Ca, and assemblages of planktonic foraminifera. Our results indicate five oceanographic phases during the last 9 kyr. During Phase I (from 9.0 to 7.0 cal kyr BP), the BC diverged offshore from the modern upwelling area because of the low sea level, increasing the influence of shelf waters and coastal upwelling plumes on foraminifera assemblages. Phase II (7.0-5.0 kyr BP) was marked by the approach of the internal front of the BC with low intensity and episodes of strong productivity that were linked primarily to the upwelling of the South Atlantic Central Water (SACW) and/or Subpolar Shelf Waters (SPSWs) (cold). Phase III (5.0-3.5 kyr BP) was a transition, marking a large oceanographic and climatic change from the weakening of the AMOC. The internal front of the BC became warm and subsurface SACW upwelling was stronger. In Phase IV (3.5-2.5 kyr BP), the BC acquired its modern dynamics, but weak NE winds weakened the SACW's contribution to upwelling events. Finally, in Phase V (last 2.5 kyr BP), the NE winds reintensified, promoting frequent episodes of upwelling and intrusion by SPSWs during the Medieval Climate Anomaly. |
| title | Planktonic foraminifera, stable isotopes and Mg/Ca ratio from Cabo Frio (Brazil) sediment cores CF10-01B and CF10-09A |
| topic | |
| url | https://doi.org/10.1594/PANGAEA.872152 |