*Article* **Improving Operational Ocean Models for the Spanish Port Authorities: Assessment of the SAMOA Coastal Forecasting Service Upgrades**

**Manuel García-León 1,2,\*, Marcos G. Sotillo 2,3, Marc Mestres 4, Manuel Espino 4 and Enrique Álvarez Fanjul 2**

	- marcos@puertos.es (M.G.S.); enrique@puertos.es (E.Á.F.)
	- Laboratori d'Enginyeria Marítima, Universitat Politècnica de Catalunya BarcelonaTech, Jordi Girona 1-3, Mòdul D1, Campus Nord, 08034 Barcelona, Spain; marc.mestres@upc.edu (M.M.); manuel.espino@upc.edu(M.E.)

**Abstract:** The Puertos del Estado SAMOA coastal and port ocean forecast service delivers operational ocean forecasts to the Spanish Port Authorities since 01/2017 (originally set-up for 9 ports). In its second development phase (2019–2021), the SAMOA service has been extended to 31 ports (practically, the whole Spanish Port System). Besides, the next generation of the SAMOA service is being developed. Research is being focused on (1) updating atmospheric forcing (by combining the AEMET HARMONIE 2.5 Km forecasts and the IFS-ECMWF ones), (2) upgrading the circulation model (ROMS), and (3) testing new methodologies to nest SAMOA systems in the Copernicus IBI-MFC regional solution (with emphasis on its 3D hourly dataset). Evaluation of specific model upgrades is here presented. Model sensitivity tests have been assessed using the available in-situ and remoted sensed (i.e., RadarHF) observations. The results show that SAMOA outperforms IBI-MFC in sea level forecasting at meso- and macro-tidal environments. Improvements by the herein proposed upgrades are incremental: some of these set-ups were used in the last SAMOA operational releases (i.e., the SAM\_INI and the SAM\_ADV ones; the later currently in operations), whereas the latest test (SAM\_H3D) ensures more nesting consistency with the IBI-MFC and improves significantly surface currents and sea-surface temperature simulations.

**Keywords:** SAMOA; coastal models; operational forecasting; port circulation; dynamical downscaling; nesting techniques in operational applications; ocean model validation
