NOAA/WDS Paleoclimatology - Mayotte Coral Coupled Sr/Ca and d18O Data

We reconstruct the hydrologic history of the tropical western Indian Ocean by calculating the d18Oseawater from coupled coral Sr/Ca and d18O measurements in a massive Porites coral from Mayotte (Comoros) between 1881 and 1994. We found that the precipitation-evaporation balance varies naturally on time scales of 5-6 years and 18-25 years. High (low) SSTs are associated with positive (negative) d18Oseawater implying that atmospheric variability is linked with remote climate modes in the Indian Ocean and the tropical/extratropical Pacific Ocean. Warm El Nino-Southern Oscillation events are associated with a negative freshwater balance at Mayotte. This case study demonstrates that a much denser network of d18Oseawater reconstructions is crucial for understanding the spatial patterns of hydrological conditions.