Towards an ocean salinity error budget estimation within the SMOS mission

The SMOS (Soil Moisture and Ocean Salinity) mission will provide from 2008 onwards global sea surface salinity estimations over the oceans. This work summarizes several insights gathered in the framework of salinity retrieval studies, aimed to address an overall salinity error budget. The paper covers issues ranging from the impact of auxiliary data on SSS error to the potential exploitation of GNSS-R signals as surface’s roughness descriptor, and establishes several guidelines to approach a quasi-realistic post-launch retrieval scenario. Having defined a retrieval setup, an error budget scheme has been built, listing the different contributions to the final retrieved SSS error. On-going activities refer to the fulfillment of the pending issues of the error budget, which are mostly relevant to residual bias mitigation techniques, and Sun and Faraday rotation effect characterization.