SMOS: Measuring Sea Surface Salinity from Space

In May 1999, the European Space Agency (ESA) selected SMOS as an Earth Explorer Opportunity mission. One of its goals is the generation of global Sea Surface Salinity (SSS) maps. The sensor embarked is an L-band interferometric radiometer with full-polarimetric capability called MIRAS. The retrieval of SSS from microwave measurements is based on the fact that the brightness temperature (TB) of seawater is a function of the dielectric constant, temperature and sea surface state (roughness, foam,...). The sensitivity of T B BB to SSS is maximum at L-band, but it is necessary to quantify the other effects to have a reliable SSS retrieval. In order to improve the present understanding of these effects on TB, ESA sponsored the WISE (Wind and Salinity Experiment) 2000 and 2001 and EuroSTARRS field campaigns. These experimental results are of great importance for the development of sea surface emissivity models that will be used in the future SMOS SSS retrieval algorithms. This paper presents an overview of campaigns performed as well as the activities there has