SIOPACT - Developing a ~250 year climate record for the Southeastern Indian Ocean sector of the Indo-PACific warm pool and its global climate Teleconnections
Final Report Abstract
We investigated long-term climate variability and its underlying drivers in the tropical southeast Indian Ocean (SEIO), a region critical to the global climate system and strongly influenced by the Indo-Pacific Warm Pool and the Indonesian Throughflow (ITF). Using sub-seasonally resolved coral Sr/Ca and δ18O records from Browse Island spanning 1753–2011, this work provides new insights into sea surface temperature (SST) and salinity variability over interannual to multidecadal timescales. The Sr/Ca record reveals robust correlations with instrumental SST, capturing key interannual variability linked to the El Niño– Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), as well as long-term industrial era warming starting at the end of the Little Ice Age (LIA) and accelerating trends since the early 20th century, indicative of anthropogenic forcing. The δ18Oseawater(sw) record, reconstructed from paired Sr/Ca and δ18O data, highlights hydrological variability driven by precipitation-evaporation dynamics, closely tied to the Australian monsoon, and ITF transport. Long-term trends in δ18Osw indicate centennial variability, reflecting complex interactions between monsoon-driven freshwater fluxes and ITF circulation. Freshening since the 1950s is likely caused by the intensified hydrological cycle due to anthropogenic warming. The findings underscore the influence of interannual and decadal variability, particularly the IOD, ENSO, and the Interdecadal Pacific Oscillation (IPO), on SST and salinity, mediated by the combined effects of monsoon dynamics and ITF transport. Discrepancies between δ18Osw and Sr/Ca- SST trends emphasize the need for further investigation into the driving mechanisms of longterm climate variability. This includes synthesizing temperature and salinity proxies, expanding seawater δ18O monitoring, and integrating additional paleoclimate records, such as tree rings and speleothems, to better resolve the interactions between hydrological processes, ocean circulation, and climate variability in the SEIO. These results contribute to improving our understanding of the region’s role in past and future climate dynamics.
Publications
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Cross-validation of high-resolution Sr/Ca and δ18O of Porites corals from Browse Island, North Western Australia. Poster at 13th International Conference on Paleoceanography (ICP13) in Sydney Sep. 2019
Krawczyk, H., Zinke, J., Lough, J., Struck, U. & Garbe-Schönberg, D.
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Best Practices for Coral Proxy-SST Calibration for 20th Century δ18Οsw Reconstruction – Initial Results from CoralHydro2k presented at AGU 2020 Fall Meeting
Walter, R. & the PAGES CoralHydro2k
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High-resolution climate data reconstruction from Porites corals from Browse Island, North Western Australia. Lightning talk at RCUK2020 (Reef Conservation UK)
Krawczyk, H., Zinke, J., Lough, J., Garbe-Schönberg, D. & Hambach, B.
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Assessing the impact of Sr/Ca-SST calibrations on coral-based seawater δ18O reconstructions - First results from PAGES CoralHydro2k. Copernicus GmbH.
Walter, Rachel
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High-resolution 20th century record of coral Sr/Ca and δ18O from Browse Island, NW Australia. Accepted for virtual ICRS2021 (14th International Coral Reef Symposium) July 2021
Krawczyk, H.; Zinke, J., Lough, J.; Cantin, N., Garbe-Schönberg, D.; Hambach, B., Wilson, P. & Boom, A.
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North West Australian coral record of seasonal sea surface temperatures and hydroclimate associated with Australian monsoon and Indonesian Throughflow dynamics since the 1750s. AGU (American Geophysical Union) Fall Meeting 2021, Washington D.C., USA
H. Krawczyk, J. Zinke, J. Lough, D. Garbe-Schönberg, B. Hambach, N. E. Cantin, P. A. Wilson & A. Boom
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Reconstructing regional hydrology from coral archives: First results from the PAGES CoralHydro2k project. Accepted for virtual ICRS2021 (14th International Coral Reef Symposium) July 2021
Sayani, H. R., Abram, N. J., Cobb, K. M., Felis, T., Walter, R., Hargreaves, J., Atwood, A., Brenner, L., DeLong, K., Ellis,B., Fischer, M., Goodkin, N., Hitt, N., Kilbourne, K.H., Krawczyk, H., Maupin, C., Murty, S., Pfeiffer, M., Ramos, R., Reed, E.V., Samanta, D., Sanchez, S.C., Zinke, J. & Zhu, F.
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Subseasonal sea surface temperature and salinity reconstructions from Northwest Australian corals recording Indonesian Throughflow and Indo-Pacific warm pool dynamics. Poster and Lightning talk at WCRP- CLIVAR Workshop on Climate Interactions among the Tropical Basins Feb. 2021
Krawczyk, H., Zinke, J., Lough, J.; Cantin, N., Garbe-Schönberg, D., Hambach, B. & Wilson, P.
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200 year high resolution proxy record from NW Australian corals capturing Indo-Pacific hydroclimate variability. (Oral) PAGES OSM 2022 (Open Science Meeting)
H. Krawczyk, J. Zinke, J. Lough, D. Garbe-Schönberg, B. Hambach, N. Cantin, P. Wilson & A. Boom
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The CoralHydro2k Database: a global, actively curated compilation of coral δ 18 O and Sr / Ca proxy records of tropical ocean hydrology and temperature for the Common Era. Copernicus GmbH.
Walter, Rachel M.; Sayani, Hussein R.; Felis, Thomas; Cobb, Kim M.; Abram, Nerilie J.; Arzey, Ariella K.; Atwood, Alyssa R.; Brenner, Logan D.; Dassié, Émilie P.; DeLong, Kristine L.; Ellis, Bethany; Fischer, Matthew J.; Goodkin, Nathalie F.; Hargreaves, Jessica A.; Kilbourne, K. Halimeda; Krawczyk, Hedwig; McKay, Nicholas P.; Murty, Sujata A.; Ramos, Riovie D. ... & Zinke, Jens
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250 year high resolution proxy record from NW Australian corals capturing Indo-Pacific hydroclimate variability. (invited speaker) First thematic focus meeting of the DFG Priority Programme “Tropical Climate Variability & Coral Reefs”, Bremen, Germany, 2023
H. Krawczyk, J. Zinke, J. Lough, D. Garbe-Schönberg, B. Hambach, N. E. Cantin, P. A. Wilson & A. Boom
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Inconsistent Coral Bleaching Risk Indicators Between Temperature Data Sources. Earth and Space Science, 10(7).
Neo, V. H. F.; Zinke, J.; Fung, T.; Merchant, C. J.; Zawada, K. J. A.; Krawczyk, H. & Maina, J. M.
