The SURVOSTRAL program is a long term study of upper ocean temperature and salinity changes in the Southern Ocean between Tasmania and Antarctica.  The program uses data collected from the regular ASTROLABE voyages between Hobart and Antarctica, and is a co-operation between the IPEV (France),  CSIRO (Australia) and the Scripps Institution of Oceanography (USA).

The main objectives are to study:

• the seasonal, interannual and decadal variability of the upper ocean heat content and heat balance in the Southern Ocean;
• the different thermal and haline fronts;
• the variations in transport and structure of the Antarctic Circumpolar Current;
• the surface salinity variations, and their relation to the freshwater budget of the Southern Ocean;
• the variations of surface eddy heat, salt and momentum fluxes across the ACC.

This programme, based on high density XBT and XCTD measurements and continuous surface thermosalinograph data started in 1992-93, a nd provides the longest in-situ time series of seasonal temperature variations in the Southern Ocean. It is an integral part of CLIVAR. The scientific studies based on the SURVOSTRAL data are financed by the French TOSCA program.