El Niño Southern Oscillation (ENSO) and decadal‐scale climate variability at 10°N in the eastern Pacific from 1893 to 1994: A coral‐based reconstruction from Clipperton Atoll

We have developed a 101 year (1893–1994) subseasonal oxygen (δ18O) and carbon (δ13C) isotopic time series from Clipperton Atoll in the eastern Pacific using the coral Porites lobata. In agreement with Linsley et al. [1999] we find that seasonal and interannual coral δ18O variability at Clipperton results from variability in both water temperature and salinity. Three new coral time series demonstrate the reproducibility of a secular coral δ18O trend of −0.35‰ since 1910 but show varying δ13C trends. Strong decadal‐scale variability in the δ18O record appears related to the Pacific Decadal Oscillation (PDO) through postulated changes in the strengths of the Equatorial Counter Current and North Equatorial Current. Interannual variability in this coral δ18O record is directly related to the El Niño Southern Oscillation (ENSO) and isolation of this frequency band indicates reduced ENSO variability in the eastern equatorial Pacific in the period 1925 to ∼1940, in agreement with instrumental and other Pacific coral records.