The Unresolved Obstacles Source Term (UOST) is a general methodology for parameterizing the dissipative effects of subscale islands, cliffs, and other unresolved features in ocean wave models. Since it separates the dissipation from the energy advection scheme, it can be applied to any numerical scheme or any type of mesh. UOST is now part of the official release of WAVEWATCH III, and the freely available package alphaBetaLab automates the estimation of the parameters needed for the obstructed cells. In this contribution, an assessment of global regular and unstructured (triangular) wave models employing UOST is presented. The results in regular meshes show an improvement in model skill, both in terms of spectrum and of integrated parameters, thanks to the UOST modulation of the dissipation with wave direction, and to considering the cell geometry. The improvement is clear in wide areas characterized by the presence of islands, like the whole central-western Pacific Basin. In unstructured meshes, the use of UOST removes the need of high resolution in proximity of all small features, leading to (a) a simplification in the development process of large scale and global meshes, and (b) a significant decrease of the computational demand of accurate large-scale models.

Drifting Fish Aggregating Devices (dFADs) are small drifting platforms with an attached solar powered buoy that report their position with daily frequency via GPS. We use data of 9,440 drifting objects provided by a buoys manufacturing company, to test the predictions of surface current velocity provided by two of the main models: the NEMO model used by Copernicus Marine Environment Monitoring Service (CMEMS) and the HYCOM model used by the Global Ocean Forecast System (GOFS).

Effects of open shelters on limestone decay: The case-study of the Bishop's Palace archaeological site in Witney (England) 41 C. Cabello Briones Air quality assessment and protection treatments impact on the collection of the Museo Naval (Madrid, Spain) 47

<p>European coasts are often exposed to severe storms that trigger extreme water-level conditions, leading to coastal flooding and erosion. With the objective to provide useful and timely information on coastal flood risk from extreme sea level events at European scale, a proof-of-concept for a European Coastal Flood Awareness System (ECFAS) is being developed as part of a European Union’s Horizon 2020 project. ECFAS could contribute to the evolution of the Copernicus Emergency Management Service.</p><p>ECFAS uses state-of-the-art coastal monitoring and forecasting technologies and datasets suited to regional-to-local scale assessments. For its early-warning component, ECFAS capitalizes on the ocean forecasting systems operated by the Copernicus Marine Service (CMEMS). Such forecasts are combined with a coastal-stretch-specific, pre-computed flood catalog to provide a mapping of the inundation depth and extent. Consecutively, the ECFAS-Rapid and Risk and Recovery Mapping component is activated which allows an operational assessment of the socio-economic impact of marine storms.</p><p>In this presentation, we focus on the skill of the CMEMS ocean hydrodynamic models that provide the marine hazard component to the system. We apply a methodology to detect storm-driven extreme sea level events from tide-gauge records and validate the event peak representation and forecast lead time impact. For best analyses, results show satisfactory results but a general underprediction of peak magnitudes of 10% for water levels and 18% for surges across the detected storm events. In average, the models are capable of independently flagging 76% of the observed events. Forecasts show insignificant lead time impact up to a 4-day lead time, demonstrating the suitability of the systems for early warning applications. Finally, by separating the surge and tidal contributions to the extremes, we identify the source of the prediction misfits and provide recommendations for the evolution of the CMEMS forecasting models for coastal flooding applications.</p><p>The ECFAS (European Coastal Flood Awareness System) project has received funding from the EU H2020 research and innovation programme under Grant Agreement No 101004211.</p>