Validation and Intercomparison Studies Within GODAE

During the Global Ocean Data Assimilation Experiment (GODAE), seven international operational centers participated in a dedicated modeling system intercomparison exercise from February to April 2008. The objectives were: (1) to show GODAE global-ocean and basin-scale forecasting systems of different countries in routine interaction and continuous operation, (2) to assess the quality and perform scientific validation of the ocean analyses and the forecasting performance of each system, and (3) to learn from this exercise in order to increase interoperability and collaboration in real time. The validation methodology has steadily improved through several validation experiments and projects performed within the operational oceanography community. It relies on common approaches and standardization of outputs, with a set of diagnostics based on fully detailed metrics that characterize its strengths and weaknesses, but it also provides error levels for ocean estimates. The ocean forecasting systems provide daily fields of mesoscale water mass distribution and ocean circulation, with an option for sea-ice variations. We present a subset of the intercomparisons performed over different areas, showing general ocean circulation in agreement with known patterns. We also present some accuracy assessments through comparison with observed data.