The SURVOSTRAL thermosalinograph data has allowed us to determine the seasonal and interannual structure of the surface salinity and temperature fields (Chaigneau et Morrow, 2003). A seasonal climatology has been constructed from SURVOSTRAL data. The seasonal temperature cycle is well represented in the Levitus climatology, but the Levitus salinity is too smooth in the frontal regions, and too variable in the Antarctic Zone south of 54°S.
The SURVOSTRAL data show a good correlation between the summer salinity south of 61°S and the variations in sea-ice cover the previous winter : large sea-ice cover in winter is followed by a reduction in SSS south of 61°S.
In summer, the surface frontal position is often 50-100 km north of its subsurface position, since the summer heating decouples the warmer surface layer from the deeper layers and the surface layer is then driven north by the wind-driven Ekman transport.
We have also identified that SSS is a clearer indicator of the surface polar frontal position than SST (see Figure).
SURVOSTRAL will be used as a high-latitude validation site for the future SMOS and Aquarius satellite sea surface salinity missions.