SST estimation using collocation: method refinements and seasonal variability

The collocation method can be fruitfully applied in SST estimation on repeated mission tracks. Some applications have been carried out in the western Mediterranean Sea using ERS1-ERM and TOPEX/POSEIDON data. In this work some refinements of the method are analyzed to obtain improvements in the estimates of the stationary component of the SST in the area mentioned above. Moreover, seasonal variability is investigated, on the basis of the previous stationary SST estimate, using ERS 1 repeats. Some comparisons are made with the circulation model obtained in the whole Mediterranean Sea from a different elaboration of the TOPEX/POSEIDON data. They prove that altimetric-derived seasonal variability is in quite good agreement with such circulation patterns, although they are extremely weak and display irregular features.