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| Shao, Jun; Stott, Lowell D.; Gray, William R.; Greenop, Rosanna; Pecher, Ingo; Neil, Helen L.; Coffin, Richard B.; Davy, Bryan; Rae, James W.b.. |
| Identifying processes within the Earth System that have modulated atmospheric pCO2 during each glacial cycle of the late Pleistocene stands as one of the grand challenges in climate science. The growing array of surface ocean pH estimates from the boron isotope proxy across the last glacial termination may reveal regions of the ocean that influenced the timing and magnitude of pCO2 rise. Here we present two new boron isotope records from the subtropical‐subpolar transition zone of the Southwest Pacific that span the last 20 kyr, as well as new radiocarbon data from the same cores. The new data suggest this region was a source of carbon to the atmosphere rather than a moderate sink as it is today. Significantly higher outgassing is observed between ~16.5‐14... |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00514/62525/66838.pdf |
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| Stott, Lowell D; Shao, Jun; Yu, Jimin; Harazin, Kathleen M. |
| The prevailing hypothesis to explain pCO2 rise at the last glacial termination calls upon enhanced ventilation of excess respired carbon that accumulated in the deep sea during the glacial. Recent studies argue lower [O2] in the glacial ocean is indicative of increased carbon respiration. The magnitude of [O2] depletion was 100–140 µ mol/kg at the glacial maximum. Because respiration is coupled to δ13C of dissolved inorganic carbon (DIC), [O2] depletion of 100–140 µ mol/kg from carbon respiration would lower deep water δ13CDIC by ∼1‰ relative to surface water. Prolonged sequestration of respired carbon would also lower the amount of 14C in the deep sea. We show that Pacific Deep Water δ13CDIC did not decrease relative to the surface ocean and Δ14C was only... |
| Tipo: Text |
Palavras-chave: Carbon isotope proxies; Carbon respiration hypothesis; Deep water ventilation; Glacial pCO2. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00682/79437/82043.pdf |
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