NOAA/WDS Paleoclimatology - Palau 215 Year Coral Stable Isotope Data

The West Pacific Warm Pool (WPWP) is a critical region of the global climate system that is closely linked with the El Nino-Southern Oscillation (ENSO). We have generated two monthly resolved coral d18O (d18OCRL) records from a key region of the WPWP, the Republic of Palau (7N, 135E). The isotopic time series span the years 1793-2008 and 1899-2008. During the period of overlap, the two records are well correlated at interannual and annual periods. Multiple lines of evidence demonstrate a strong ENSO signal in Palau d18OCRL. Our records are consistent with previous investigations of twentieth-century tropical Pacific climate variability. We identify a regionally coherent bi-decadal cycle in the WPWP following the termination of the Little Ice Age. The Palau d18OCRL records show long-term trends towards warming/freshening, suggesting a century scale increase in the strength of the hydrologic cycle associated with the WPWP. Our study represents an important addition to the network of tropical paleo-archives.