A coral delta O-18 record of ENSO driven sea surface salinity variability in Fiji (south-western tropical Pacific)

The role of salinity in the dynamics and thermodynamics of El Nino - Southe rn Oscillation (ENSO) events is increasingly being investigated. However, i nstrumental records of salinity are scarce and short in the tropical Pacifi c, and there is a clear need for a reliable salinity proxy to extend our kn owledge of ENSO through time. Here, we present 40 years of delta O-18 data from a Fiji coral(16 degrees 48'S - 177 degrees 27'E). The coral delta O-18 signal integrates both sea surface temperature (SST) and sea surface salin ity (SSS) Variations. On a seasonal timescale, delta O-18 is mainly driven by SST changes whereas on an interannual ENSO timescale, it is almost exclu sively affected by SSS variability. Since interannual fluctuations of SSS a re rather well correlated to the Southern Oscillation Index in Fiji, coral delta O-18 call be used to reconstruct palco-salinity data with some level of confidence. This may help for tracking ENSO influences back in time.