Analysis and comparison of coupled and uncoupled simulations with the COAWST model during the Gloria Storm (January 2020) in the northwestern Mediterranean Sea

Numerical simulations of the ocean and atmosphere provide crucial information for climate policies and socio-economic decisions. A coupled atmosphere-ocean model can potentially improve the representation of processes and forecast fields compared to an uncoupled one. This work aims to assess under which conditions the coupled model performs better than the uncoupled one and evaluate those differences in a high-energy storm in the northwestern Mediterranean area, which was modelled to compare coupled and uncoupled simulations of storm Gloria (January 2020). The model was validated and verified with observations from weather stations, atmospheric soundings, buoys, and the operational models of METEOCAT. Although the coupling of the models does not substantially affect the atmospheric large-scale flows, a significant impact has been found for the small and mesoscale structures. On the ocean, differences between the coupled and uncoupled models arise over the entire spatial and temporal scales, which the coupling exhibits better performance.