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| Auteurs principaux: | , , |
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| Format: | Dataset Open Access |
| Langue: | en |
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PANGAEA
2018
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| Accès en ligne: | https://doi.org/10.1594/PANGAEA.890942 |
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| _version_ | 1867171372323569664 |
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| author | Ng, Hong Chin Robinson, Laura F McManus, Jerry F |
| author_facet | Ng, Hong Chin Robinson, Laura F McManus, Jerry F |
| collection | Datos científicos de ciencias marinas y ambientales |
| contents | Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. However, the exact timing and magnitude of past AMOC shifts remain elusive, which continues to limit our understanding of the driving mechanisms of such climate variability. Here we show a remarkably consistent signal of the 231Pa/230Th proxy that reveals a spatially coherent picture of western Atlantic circulation changes over the last deglaciation, during abrupt millennial-scale climate transitions. At the onset of deglaciation, we observe an early slowdown of circulation in the western Atlantic from around 19 to 16.5 thousand years ago (ka), consistent with the timing of accelerated Eurasian ice melting. The subsequent weakened AMOC state persists for over a millennium (~16.5-15 ka), during which time there is substantial ice rafting from the Laurentide ice sheet. This timing indicates a role for melting ice in driving a two-step AMOC slowdown, with a positive feedback sustaining continued iceberg calving and climate change during Heinrich Stadial 1. |
| format | Dataset Open Access |
| id | pangaea_https___doi_org_10_1594_PANGAEA_890942 |
| institution | PANGAEA |
| language | en |
| publishDate | 2018 |
| publisher | PANGAEA |
| record_format | pangaea |
| spellingShingle | Atlantic Pa/Th composite, new tropical Atlantic sedimentary Pa/Th data and age models Ng, Hong Chin Robinson, Laura F McManus, Jerry F Abrupt climate changes in the past have been attributed to variations in Atlantic Meridional Overturning Circulation (AMOC) strength. However, the exact timing and magnitude of past AMOC shifts remain elusive, which continues to limit our understanding of the driving mechanisms of such climate variability. Here we show a remarkably consistent signal of the 231Pa/230Th proxy that reveals a spatially coherent picture of western Atlantic circulation changes over the last deglaciation, during abrupt millennial-scale climate transitions. At the onset of deglaciation, we observe an early slowdown of circulation in the western Atlantic from around 19 to 16.5 thousand years ago (ka), consistent with the timing of accelerated Eurasian ice melting. The subsequent weakened AMOC state persists for over a millennium (~16.5-15 ka), during which time there is substantial ice rafting from the Laurentide ice sheet. This timing indicates a role for melting ice in driving a two-step AMOC slowdown, with a positive feedback sustaining continued iceberg calving and climate change during Heinrich Stadial 1. |
| title | Atlantic Pa/Th composite, new tropical Atlantic sedimentary Pa/Th data and age models |
| topic | |
| url | https://doi.org/10.1594/PANGAEA.890942 |