SMOS Mission Reveals the Salinity Structure of the Indian Ocean Dipole

This letter reports the European Space Agency's Soil Moisture and Ocean Salinity (SMOS) observations of the sea surface salinity (SSS) structure during an Indian Ocean Dipole (IOD) event. Comparisons with Argo data show that the SMOS satellite is able to resolve the observed SSS pattern in the Indian Ocean despite some challenges in the northern Indian Ocean. Results of box averages for the Java Sumatra Coast (JSC) and South Central Indian Ocean (SCIO) regions show low SSS anomalies in the former and high SSS anomalies in the latter during the 2010 negative IOD event. Analyses of salt flux and salt budget terms suggest that, in the JSC region, salt tendency is an interplay between freshwater forcing and horizontal advection terms, with increased precipitation having a higher impact in driving SSS anomalies than advection. In the SCIO region, advection seems to be more important than the freshwater forcing term.