Strong glacial-interglacial variability in upper ocean hydrodynamics, biogeochemistry, and productivity in the southern Indian Ocean
Strong glacial-interglacial variability in upper ocean hydrodynamics, biogeochemistry, and productivity in the southern Indian Ocean
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DOI：
10.1038/s43247-021-00148-0
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发表时间：
2021-05
影响因子：
7.9
通讯作者：
D. Tangunan;M. Berke;A. Cartagena-Sierra;J. Flores;J. Gruetzner;F. Jiménez‐Espejo;L. Levay;K. Baumann;O. Romero;M. Saavedra‐Pellitero;J. Coenen;A. Starr;S. Hemming;I. Hall;Stephen Luna Thibaut Christopher D. Julien G. Allison M. X Barker Brentegani Caley Charles Crespin Franzese H-Stephen-Luna-Thibaut-Christopher-D.-Julien-G.-M.-X;Stephen Barker;L. Brentegani;T. Caley;C. Charles;J. Crespin;A. Franzese;Xibin Han;S. Hines;F. J. Jiménez Espejo;J. Just;A. Koutsodendris;K. Kubota;N. Lathika;R. Norris;T. D. Dos Santos;R. Robinson;J. Rolison;M. Simon;D. Tangunan;J. van der Lubbe;M. Yamane;Hucai Zhang
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文献类型：
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作者：
D. Tangunan;M. Berke;A. Cartagena-Sierra;J. Flores;J. Gruetzner;F. Jiménez‐Espejo;L. Levay;K. Baumann;O. Romero;M. Saavedra‐Pellitero;J. Coenen;A. Starr;S. Hemming;I. Hall;Stephen Luna Thibaut Christopher D. Julien G. Allison M. X Barker Brentegani Caley Charles Crespin Franzese H-Stephen-Luna-Thibaut-Christopher-D.-Julien-G.-M.-X;Stephen Barker;L. Brentegani;T. Caley;C. Charles;J. Crespin;A. Franzese;Xibin Han;S. Hines;F. J. Jiménez Espejo;J. Just;A. Koutsodendris;K. Kubota;N. Lathika;R. Norris;T. D. Dos Santos;R. Robinson;J. Rolison;M. Simon;D. Tangunan;J. van der Lubbe;M. Yamane;Hucai Zhang
在南印度洋，副热带锋的位置-南部较冷、较新鲜的沃茨和北部较暖、较咸的沃茨之间的分界线-对上层海洋的流体动力学和海洋地球化学有很大影响。在这里，我们分析了沉积记录从厄古拉斯高原，靠近现代位置的亚热带锋，并使用kenones和颗石组合，以重建在过去的30万年的海洋条件。我们确定了一个强大的冰川间冰期的海面温度和生产力的变化与亚热带前迁移在厄古拉斯高原，以及短期的高频率的变化与高纬度日射变化。烯酮和颗石丰度，结合硅藻和有机碳记录表明高冰川出口生产力。我们的结论是，生物泵是更有效的，并加强在冰川时期，这可以部分地解释报告的大气中二氧化碳浓度的减少。
In the southern Indian Ocean, the position of the subtropical front – the boundary between colder, fresher waters to the south and warmer, saltier waters to the north – has a strong influence on the upper ocean hydrodynamics and biogeochemistry. Here we analyse a sedimentary record from the Agulhas Plateau, located close to the modern position of the subtropical front and use alkenones and coccolith assemblages to reconstruct oceanographic conditions over the past 300,000 years. We identify a strong glacial-interglacial variability in sea surface temperature and productivity associated with subtropical front migration over the Agulhas Plateau, as well as shorter-term high frequency variability aligned with variations in high latitude insolation. Alkenone and coccolith abundances, in combination with diatom and organic carbon records indicate high glacial export productivity. We conclude that the biological pump was more efficient and strengthened during glacial periods, which could partly account for the reported reduction in atmospheric carbon dioxide concentrations.