Generating SMOS Sea Surface Salinity Maps with the Help of Data Assimilation

Abstract

Since its launch in November 2009, the Soil Moisture Ocean Salinity (SMOS) satellite has been sending measures of the brightness temperature emitted by the earth surface at the microwave L-band. This information is being used to retrieve values of the sea surface salinity (SSS) and soil moisture. A hierarchy of SSS products has been defined in the SMOS data processing chain. This work focuses on the so called Level 3 (binned maps of SSS) and Level 4 (products combining SMOS data with any other source of information). In this work it is proved that a simple, but robust, data assimilation technique may be used to produce Level 4 maps of SSS by assimilating Level 3 SSS data. The numerical ocean model used here is a regional simulation of the North-Atlantic ocean. The resulting SSS is closer to in-situ (independent) SSS estimates, and the geophysical distribution of the singularity exponents has similar features that to the ones present in the singularity maps of sea surface temperature