Satellite SST and SSS Observations and Their Role to Constrain Ocean Models

Sea surface temperature (SST) and sea surface salinity (SSS) are important parameters of the ocean that influence ocean circulation, air-sea interactions, and biogeochemistry. In the past few decades, since SST measurements from space have become routine, they have been fundamental to ocean and climate research. In the past several years, satellite measurements of SSS have become available to strengthen research and applications for the oceans and the linkages with other elements of the Earth system. This chapter introduces the key principles and advantages of measuring SST and SSS from space, their complementarity use with other satellite and in situ observations, the past and current missions for these measurements, characteristics of uncertainties for the related data products, and the utility of these measurements in evaluating and constraining ocean model/assimilation systems and improving forecasts.