CoralHydro2k - Tropical ocean hydroclimate and temperature from coral archives

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CoralHydro2k timeline

 Launch
     Synthesis
       
 May 2017  2018  2019  2020

 

Overview

The PAGES Ocean2k project has 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.

coralhydro 2k 3 web
 Coral reef in the northern Red Sea. Credit: MARUM, T. Felis

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 scientific goals

> CoralHydro2k people

 

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