Validation of Satellite-Derived Salinity in the Equatorial Pacific With Specific Emphasis on the 2014–15 ENSO Event

Abstract

This letter compares satellite and in situ sea surface salinity (SSS) measurements in the tropical Pacific Ocean and validates the performance of satellite products during the 2014–15 El Nino-Southern Oscillation (ENSO) event. SSS measurements from NASA’s Aquarius salinity mission and the European Space Agency’s Soil Moisture and Ocean Salinity (SMOS) are compared with Argo float data. This comparison shows that the Aquarius and SMOS satellites are generally able to resolve the SSS in the tropical Pacific, despite some discrepancies in regions of upwelling and high precipitation. The two satellites perform better with respect to Argo in Nino 4 than in Nino 3 and Nino 1+2. However, in each region, Aquarius and SMOS are highly correlated with each other. During the 2014–15 ENSO event, each data set observes similar SSS, although some discrepancies exist. Analysis of anomalous evaporation minus precipitation during this event demonstrates that the differences between each data set are not fully explained by precipitation patterns.