Enhanced Nearshore Forecasting in Barcelona, Spain: A Next-Generation, High-Resolution Wave-Current Modelling Tool.

Effective management of urban coastlines and port areas relies heavily on accurate prediction and understanding of local coastal processes, particularly in regions where nearshore morphology and bathymetry have a significant influence on ocean circulation and wave transformation. This work presents a state-of-the-art three-dimensional modelling tool designed to improve the prediction of ocean and wave conditions in the Barcelona coastal zone. The tool uses the Coupled Ocean-Atmosphere-Wave-Sediment Transport Modelling System (COAWST) [1], which uses the Model Coupling Toolkit to synchronise the Regional Ocean Modeling System (ROMS) with the Simulating Waves Nearshore (SWAN) model. By exchanging relevant predictor variables between the models, the system more accurately captures wave-current interactions, a key mechanism governing nearshore dynamics [2].

A nested grid strategy supports the model framework, with horizontal resolutions ranging from 350 m in the outer domain to 70 m and then 14 m in progressively refined subdomains covering the Port of Barcelona and adjacent beaches. This nesting approach enables fine-scale predictions of hydrodynamic and wave processes, including spatial variations in wave height, period and direction. Bathymetric inputs are derived from EMODnet [3] and improved with site-specific high-resolution datasets, while boundary conditions are driven by Copernicus Marine Service data [4].

Rigorous validation against in-situ observations - in particular during the severe storm Celia in March 2022 - demonstrates the system's ability to provide reliable predictions of coastal hydrodynamics. By integrating wave-current processes, the model provides valuable insights for day-to-day coastal operations, long-term resource management and assessment of climate-related hazards.

Planned future work includes the assimilation of improved ocean observations and the refinement of atmospheric forcing to improve model accuracy and predictive capability. Ultimately, these efforts will inform sustainable management strategies, promote the resilience of coastal communities and support the harmonious coexistence of human activities with marine and coastal ecosystems along the Barcelona coast. This research will provide key insights for policy makers and stakeholders, promoting the sustainable integration of human activities with marine ecosystems and increasing the resilience of Barcelona's coastal communities through accurate, predictive data.

 

Funding: This research is supported by funding from the European Union’s Horizon 2020 Research and Innovation Action, under Grant Agreement No. 101037097 for the REST-COAST project.

Acknowledgments: This research is supported by the ECCO_TS project, financed by the Spanish Ministerio de Ciencia, Innovación y Universidades (contract no. PID2023-152363OB-I00). As a group, we would like to thank the  Departament de Recerca i Universitats de la Generalitat de Catalunya. Convocatòria d'ajuts a  Grups de Recerca de  Catalunya (SGR-Cat 2021) 2021SGR00600.

References: 
[1] Warner, J.C., Armstrong, B., He, R., and Zambon, J.B. (2010).  Development of a Coupled Ocean Atmosphere-Wave-Sediment Transport (COAWST) modeling system: Ocean Modeling, v. 35, no. 3, p. 230-244.
[2] Kumar, N., Warner, J.C., et al. (2011). Wave-current interaction in Willapa Bay. Journal of Geophysical Research. Retrieved from https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2011JC007387.
[3] EMODnet data base (https://www.emodnet-bathymetry.eu/).
[4] Copernicus data (https://marine.copernicus.eu/).