one publication added to basket [254708] | Oxygen depletion recorded in upper waters of the glacial Southern Ocean
Lu, Z.; Hoogakker, B.A.A.; Hillenbrand, C.-D.; Zhou, X.; Thomas, E.; Gutchess, K.M.; Lu, W.; Jones, L.; Rickaby, R.E.M. (2016). Oxygen depletion recorded in upper waters of the glacial Southern Ocean. Nature Comm. 7(11146): 8 pp. http://dx.doi.org/10.1038/ncomms11146
In: Nature Communications. Nature Publishing Group: London. ISSN 2041-1723; e-ISSN 2041-1723, more
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Authors | | Top |
- Lu, Z.
- Hoogakker, B.A.A.
- Hillenbrand, C.-D.
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- Zhou, X.
- Thomas, E.
- Gutchess, K.M.
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- Lu, W.
- Jones, L.
- Rickaby, R.E.M.
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Abstract |
Oxygen depletion in the upper ocean is commonly associated with poor ventilation and storage of respired carbon, potentially linked to atmospheric CO2 levels. Iodine to calcium ratios (I/Ca) in recent planktonic foraminifera suggest that values less than similar to 2.5 mu mol mol(-1) indicate the presence of O-2-depleted water. Here we apply this proxy to estimate past dissolved oxygen concentrations in the near surface waters of the currently well-oxygenated Southern Ocean, which played a critical role in carbon sequestration during glacial times. A down-core planktonic I/Ca record from south of the Antarctic Polar Front (APF) suggests that minimum O-2 concentrations in the upper ocean fell below 70 mu mol kg(-1) during the last two glacial periods, indicating persistent glacial O-2 depletion at the heart of the carbon engine of the Earth's climate system. These new estimates of past ocean oxygenation variability may assist in resolving mechanisms responsible for the much-debated ice-age atmospheric CO2 decline. |
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