Multi-trace-element sea surface temperature coral reconstruction for the southern Mozambique Channel reveals teleconnections with the tropical Atlantic

• Published in: Biogeosciences
• Main Authors: Zinke, Jens, d'Olivo, Juan, P., Gey, Christoph, J., Mcculloch, Malcolm, T., Bruggemann, J. Henrich, Lough, Janice, M., Guillaume, Mireille M. M.
• Other Authors: Australian Institute of Marine Science (AIMS), The ARC Centre of Excellence for Coral Reefs Studies Townsville, Australie (ARC), Freie Universität Berlin, Research School of Earth Sciences ANU, Canberra (RSES), ANU College of Science Canberra, Australian National University (ANU)-Australian National University (ANU), Ecologie marine tropicale dans les Océans Pacifique et Indien (ENTROPIE Réunion ), Institut de Recherche pour le Développement (IRD)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Excellence CORAIL (LabEX CORAIL), Institut de Recherche pour le Développement (IRD)-Université des Antilles et de la Guyane (UAG)-École des hautes études en sciences sociales (EHESS)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de La Réunion (UR)-Université de la Polynésie Française (UPF)-Université de la Nouvelle-Calédonie (UNC)-Institut d'écologie et environnement-Université des Antilles (UA), Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2019
• Subjects: [SDV.EE]Life Sciences [q-bio]/Ecology; environment; [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; North Atlantic
• Online Access: https://mnhn.hal.science/mnhn-02179314; https://mnhn.hal.science/mnhn-02179314/document; https://mnhn.hal.science/mnhn-02179314/file/Zinke%20etal%202019_Europa%20Porites%20cores.pdf; https://doi.org/10.5194/bg-16-695-2019

International audience Here we report seasonally resolved sea surface temperatures for the southern Mozambique Channel in the SW Indian Ocean based on multi-trace-element temperature proxy records preserved in two Porites sp. coral cores. Particularly, we assess the suitability of both separate and combined Sr/Ca and Li/Mg proxies for improved multi-element SST reconstructions. Overall, geochemical records from Europa Island Porites sp. highlight the potential of Sr/Ca and Li/Mg ratios as high-resolution climate proxies but also show significant differences in their response at this Indian Ocean subtropical reef site. Our reconstruction from 1970 to 2013 using the Sr/Ca SST proxy reveals a warming trend of 0.58 ± 0.1 • C in close agreement with instrumental data (0.47 ± 0.07 • C) over the last 42 years (1970-2013). In contrast, the Li/Mg showed unrealistically large warming trends, most probably caused by uncertainties around different uptake mechanisms of the trace elements Li and Mg and uncertainties in their temperature calibration. In our study, Sr/Ca is superior to Li/Mg to quantify absolute SST and relative changes in SST. However, spatial correlations between the combined detrended Sr/Ca and Li/Mg proxies compared to instrumental SST at Europa revealed robust correlations with local climate variability in the Mozambique Channel and teleconnections to regions in the Indian Ocean and southeastern Pacific where surface wind variability appeared to dominate the underlying pattern of SST variability. The strongest correlation was found between our Europa SST reconstruction and instrumental SST records from the northern tropical Atlantic. Only a weak correlation was found with ENSO, with recent warm anomalies in the geochemical proxies coinciding with strong El Niño or La Niña. We identified the Pacific-North American (PNA) atmospheric pattern , which develops in the Pacific in response to ENSO, and the tropical North Atlantic SST as the most likely causes of the observed teleconnections with the Mozambique ...