The PAGES Ocean2k project used available coral δ18O and Sr/Ca records to reconstruct regional tropical sea surface temperature for the past centuries at annual resolution. Most of these records were based on δ18O analysed in coral skeletons, a variable that reflects a combination of both the temperature and the δ18O of the seawater (δ18Osw) near the ocean surface. The coral Sr/Ca temperature proxy has the potential to decouple the temperature and δ18Osw signals from coral δ18O records in order to deliver reconstructions of δ18Osw, but only a handful of centuries-long δ18Osw reconstructions currently exist.
We intend to foster the generation of new paired coral Sr/Ca and δ18O records as well as the dynamical interpretation of available records, in order to reconstruct the spatiotemporal δ18Osw changes of the tropical to subtropical surface ocean on seasonal, interannual, and decadal to multidecadal time scales during the observational period back into the Little Ice Age.
We aim to identify the dynamical drivers of changes in δ18Osw on these timescales, including atmospheric processes such as the precipitation-evaporation balance at the sea surface and the isotopic signature of precipitation, as well as oceanic processes such as the advection of surface currents and the upwelling of deeper water masses.
While some changes in the coral-based δ18Osw reconstructions can be linked to changes in the surface freshwater balance related to ENSO extremes, the dynamical drivers of inferred lower-frequency changes in δ18Osw remain unclear in most cases. In addition, we intend to move forward the careful assessment of the errors associated with the calculation of coral-based δ18Osw reconstructions.
CoralHydro2k seawater δ18O database - July 2021
Have you collected seawater δ18O data, but have nowhere to store it? Would you like to make your data publicly accessible (facilitating open science while making program managers and journal editors happy)? Are you interested in helping members of the modeling, observational, and paleo oceanographic communities better leverage your datasets in the study of climate variability and change?
If you don’t have data of your own, but know of a dataset that should be included in the database, please feel free to submit the DOI or citation via our Google Form: https://forms.gle/M263p7SM7mteQbrf9
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New Science to Policy paper - July 2021
Project leader Thomas Felis was involved in the Science to Policy paper "Rebuilding Coral Reefs: A Decadal Grand Challenge" released during the 14th International Coral Reef Symposium in July 2021. This paper is from the International Coral Reef Society (ICRS) and Future Earth Coasts, with Thomas as a contributing author. > Access the paper here