**6. Conclusions**

#### *6.1. Assessment of the SAMOA Coastal Forecasting Service Upgrades*

The Puertos del Estado SAMOA coastal and port ocean forecast service has delivered operational ocean forecast products to Spanish Port Authorities since 01/2017. The service provides daily forecasts of sea-level, circulation, temperature and salinity fields at horizontal resolution that range from 350 m (Coastal domains) to 70 m (Port domains). The system was successfully implemented at nine ports in the SAMOA-1 project (2014–2017); and it was expanded, improving the model set-up, to 31 ports at the end of SAMOA-2 project (2018–2021).

This contribution has assessed the incremental upgrades that have been developed in the SAMOA system from 2018 to 2021. In chronological order, it has been tested (at different ports) the following three main set-ups:


The protocol proposed to assess these SAMOA model set-up upgrades focuses on evaluating in the Spanish ports the simulation of ocean variables (typically, the sea level, currents, surface temperature and salinity), validating them with available in-situ and remote-sensed observations (from tide gauges, mooring buoys and HF Radar stations). To check model sensitivities, as well as to evaluate the potential added value related to the proposed modifications, each SAMOA model test run is always compared with a control SAMOA run (i.e., the operational version of the SAMOA system at the time of the test), and with the CMEMS IBI\_PHY parent solution.

Applying this protocol, it was demonstrated that:


(iv) Finally, this contribution summarizes the impact of the incremental model upgrades performed in the SAMOA operational circulation system since 2018. Indeed, two of the SAMOA model set-ups here shown (SAM\_INI and SAM\_ADV) have been the base for the last two operational SAMOA releases (launched in October 2018 and October 2019, respectively). The SAM\_ADV model configuration is the current SAMOA operational set-up, but it is expected to be upgraded in 2022 by the also here tested SAM\_H3D one. This contribution demonstrates that the proposed SAM\_H3D configuration enhances the current SAMOA solution, especially in terms of surface currents and SST.

#### *6.2. Recommendations for Coastal Forecasting Services and Future SAMOA Perspectives*

This contribution has presented the SAMOA circulation system as a downstream service that benefits from Copernicus regional products. The authors recommend the use of products that ensure proper nesting between the parent solution and the local application. In this sense, the use of the hourly-3D IBI-MFC forecast dataset has contributed to improve the circulation and sea temperature fields (as shown in the SAM\_H3D set-up). It has been shown, that the error metrics decrease when the boundary conditions have hourly-averaged resolution (be it sea-level, currents, sea temperature and salinity). This product ensures more consistency with the parent solution than the previous SAMOA releases (hourlyaveraged sea-level and barotropic currents; but daily-averaged total currents, temperature and salinity).

High resolution atmospheric forcings and the proper air-sea parameterizations have also proven to be relevant in modelling local processes, such as wind-jets. The COARE 3.5 bulk-formula (implemented in SAM\_H3D) has shown better skill than COARE 3.0. The HSIMT-TVD scheme contributed to improve sharp gradients in the sea surface temperature solution.

This research has also identified the following future perspectives for the development of SAMOA:


The joint action of these synergistic developments will reinforce SAMOA leitmotif: a downstream service, fed by Copernicus regional products, that enhances predictive capabilities on local coastal processes at Spanish Port zones.

**Author Contributions:** Conceptualization, M.G.S., E. Á.F. and M.G.-L.; methodology, M.G.-L., M.G.S.; software, M.G.S., M.G.-L. and M.M.; validation, M.G.-L.; formal analysis, M.G.S., M.G.-L., E. Á.F.; investigation, M.G.S., M.G.-L., M.M.; resources, E. Á.F. and M.G.S.; data curation, M.G.-L. and M.M.; writing—original draft preparation, M.G.-L., M.G.S.; visualization, M.G.-L., M.G.S.; supervision, E. Á.F., M.G.S. and M.E.; project administration, E. Á.F., M.G.S. and M.E.; funding acquisition, E. Á.F. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding. **Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The SAMOA circulation forecast data and the observations used in this contribution can be downloaded from Puertos del Estado OpenDAP catalog: (https://opendap. puertos.es/thredds/catalog.html, accessed on 18 January 2022). The Copernicus Regional IBI-MFC solution can be downloaded at Copernicus Marine Environmental Monitoring Service (CMEMS) (http://marine.copernicus.eu/, accessed on 18 January 2022).

**Acknowledgments:** The authors acknowledge support from the SAMOA-2 initiative (2018–2021), co-financed by Puertos del Estado (Spain) and the Spanish Port Authorities. This contribution has been conducted using E.U. Copernicus Marine Service Information. Specifically, from its NRT forecast products at the IBI area. Likewise, ocean in-situ and HF-radar observations from the Puertos del Estado monitoring network are also duly acknowledged.

**Conflicts of Interest:** The authors declare no conflict of interest. **Abbreviations** The following abbreviations are used in this manuscript: ADCP Acoustic Doppler Current Profiler AEMET Agencia Estatal de Meteorología de España (Spanish Met Office) CMA Cuadro de Mando Ambiental (Environmental Control Panel, see Section 2) CMEMS Copernicus Marine Service COARE Coupled Ocean-Atmosphere Response Experiment COE Coefficient of Efficiency (see Section 3.4, Equation (1)) CORE Coordinated Ocean-Ice Reference Experiment CST Coastal buoy from the REDCOS network (Tables 3–5) CTD Conductivity, Temperature and Depth ECMWF European Centre for Medium-Range Weather Forecasts ECMWF-IFS European Centre for Medium-Range Weather Forecasts—Integrated Forecast System ESEOO Establecimiento de un Sistema Español de Oceanografía Operacional (Project) EXT Deep-water buoy from the REDEXT network (Tables 3–5) EuroGOOS European Global Ocean Observing System EU European Union HARMONIE HIRLAM-ALADIN Research on Mesoscale Operational NWP in Euromed HF-Radar High Frequency Radar HIRLAM High Resolution Limited Area Model HSIMT-TVD High-Order Spatial Interpolation at the Middle Temporal level coupled with a Total Variation Diminishing limiter IBI-MFC Iberian-Biscay-Ireland—Monitoring and Forecasting Centre IBI\_PHY IBI-MFC Circulation Forecasting System IBI-WAV IBI-MFC Wave Forecasting System NARVAL North Atlantic Regional VALidation NRT Near-Real Time OBC Open Boundary Condition PdE Puertos del Estado (Spanish State Ports, public enterprise for port management) REDEXT Deep-water Buoy Monitoring Network from Puertos del Estado REDCOS Coastal Buoy Monitoring Network from Puertos del Estado REDMAR Tidal Station Monitoring Network from Puertos del Estado RMS Root-Mean Square Error ROMS Regional Ocean Modeling System SAM\_INI SAMOA initial set-up (see Section 3.1 and Table 1) SAM\_ADV SAMOA advanced set-up (current release, see Section 3.2 and Table 1) SAM\_H3D SAMOA H3D set-up (forthcoming release, see Section 3.3 and Table 1)

