Coral monitors of El Nino/Southern Oscillation dynamics across the equatorial Pacific

ENSO variability produces distinct thermal and chemical signals in the surface ocean. Shallow-growing corals from sensitive Pacific sites incorporate these anomalies in the isotopic and trace metal chemistry of their aragonite skeletons. Short (~20 yr) coral records provide independent monitors of the ENSO system at three sites across the Pacific basin: the Galapagos (1°S, 91°W), Tarawa Atoll (1°N, 173°E), and Bali (8°S, 115°E). Galapagos Cd/Ca, Ba/Ca, and δ¹⁸O records reflect the degree of regional upwelling in the eastern Pacific, which is suppressed during warm ENSO conditions. Oxygen isotopic data from Tarawa Atoll corals record the intense precipitation that the eastward displacement of the Indonesian Low brings to this region during warm ENSO periods. An independent record of Mn/Ca from one of these corals reflects the weakening and reversal of the trade winds that may trigger the onset of warm ENSO conditions basinwide. Finally, δ¹⁸O from a Bali coral reflects the weakening of the Indonesian monsoon associated with warm ENSO periods. -from Authors