Salinity records for the 1997-98 El Nino from Western Pacific corals

[1] Seasonal sea surface salinity (SSS) records can be of great value in reconstructing El Nino/Southern Oscillation (ENSO) variability in the equatorial Western and Central Pacific, a region where ENSO-related evaporation and precipitation (E-P) changes are dramatic. The delta(18)O values of coral skeleton (delta(18)O(coral)) reflect seawater delta(18)O (delta(18)O(seawater)) changes, which in tropical oceans are also generally influenced by E-P changes. Therefore, delta(18)O(coral) is a good indicator of rainfall and ENSO variability. We present biweekly data from Palau, in the northern part of the Western Pacific Warm Pool, for the period 1998-2000, which indicate a strong quantitative relationship between delta(18)O(coral), sea surface temperature, delta(18)O(seawater) and SSS. The coral skeletal delta(18)O values documented the SSS changes after the 1997-98 El Nino; therefore, delta(18)O(coral) can be used to estimate paleosalinity changes. However, the slope of the delta(18)O(seawater) - SSS relationship cannot be assumed to be constant throughout the tropics, making site-specific calibrations is essential.