Forecasting the Aegean Sea hydrodynamics within the POSEIDON-II operational system

The development and first assessment of a high resolution eddy-resolving forecasting system for the Aegean Sea hydrodynamics, developed as part of the POSEIDON-II European Economic Area (EEA) Grants project and the European Coastal Sea Operational Observing and Forecasting (ECOOP) European Union (EU) project, is presented.The system uses an assimilation scheme based on a localized version of the Singular Evolutive Extended Kalman (SEEK) filter with partial evolution of its correction directions.The filter is used to correct the forecast state of a 1/30o Princeton Ocean Model (POM) of the Aegean Sea on a weekly basis. Data assimilation experiments are performed over a 12-month period to estimate the impact of observations insertion on the forecasting skill of the modelling system.The accuracy of the hydrodynamic state identification is assessed by the relevance of the assimilation system in fitting the data, and in forecasting future variability. The results of the assimilation system are also inter-compar...