Satellite-based T-S diagrams derived from SMOS, Aquarius and OSTIA data

Abstract

Temperature Salinity (T-S) diagrams emphasize the relationship between observed values of temperature and salinity in the ocean and connect them to density. Specific T-S curves characterize water masses and can be used to identify them in regions other than their formation area. The SMOS and Aquarius/SAC-D satellite missions provide a means to study the temporal variation of the surface T-S signature for the first time on a global scale. The present study derives experimental satellite based T-S diagrams. The main objectives are to characterize the (co-) variability of Sea Surface Temperature (SST) and Sea Surface Salinity (SSS) and to understand the unique information that SMOS and Aquarius are providing with respect to existing climatology or in-situ data as well as the processes governing the distribution and variability of SSS. The T-S diagrams are produced from SMOS and Aquarius Optimal Interpolated SSS and OSTIA SST. They are compared with T-S diagrams derived from an ARGO Optimal Interpolated product and the World Ocean Atlas 2009 climatology, respectively. The temporal variability is studied for each ocean basin. Comparison with the ARGO based T-S diagrams might provide evidence of SSS biases and errors currently experienced by the satellites. A method is under investigation to separate the retrieval errors from the additional information that the satellite data may contain with respect to the ARGO data. Linking the information from the horizontal T-S diagrams with vertical profiles can hopefully provide insight into water mass formation and help to identify potential formation areas