Evaluation of Ocean Syntheses: studying the evolution of the ocean state over the last decades with COST Action ES1402

The COST Action ES1402 “Evaluation of Ocean Syntheses” (EOS) was initiated in 2014 in order to establish and consolidate a network of European scientists working on the generation and evaluation of ocean syntheses and reanalyses. Ocean syntheses are comprehensive estimations of the ocean state over the last decades (mainly temperature, salinity, sea level and currents) calculated by merging hydrodynamic ocean models and all available observations using data assimilation. Ocean reanalyses are used in operational estimations of the ocean state, for short-term predictions aiming at studying specific processes, for seasonal and decadal predictions, and for climate-related activities.