Mid-late Holocene El Nino variability in the equatorial Pacific from coral microatolls

[1] Oxygen isotope ratios in Porites microatolls from Christmas Island in the central Pacific provide high-resolution proxy records of El Nino-Southern Oscillation (ENSO) variability since 3.8 thousand years ago (ka). Compared with modern microatolls, reconstructions from fossil microatolls imply that interannual variations in ENSO sea-surface temperature and precipitation were less intense 3.8-2.8 ka, but more pronounced at 1.7 ka. Amplification of ENSO at similar to2 ka is consistent with precessional changes in insolation seasonality, but exceeds model predictions and may reflect stronger rainfall teleconnections through enhanced interaction between the Southern Oscillation and the Pacific Intertropical Convergence Zone.