An high resolution coupled ocean-atmosphere numerical simulation for the Adriatic Sea

The role of Sea Surface Temperature in the weather forecast has been investigated in the past years and its role in modulating local circulation has been assessed. In this context, a coupled ocean-atmosphere numerical simulation has been developed. The three models WRF, ROMS and SWAN are coupled together within the Coupled Ocean-Atmosphere-Wave-Sediment Transport modeling system (COAWST) for the Adriatic Sea. For what concerns the atmospheric component the WRF-ARW model is used. Two domains run independently: a low resolution domain (15 km) initialized using NCEP analyses at 0.25 degrees and a high resolution domain (3 km) covering the Adriatic regions, initialized using the WRP low- resolution output. For what concern the oceanographic component, the circulation model ROMS and the wave driver SWAN run on the same high horizontal resolution grid (1km). The vertical discretization of ROMS is performed using 30 sigma layers while the river inputs consist of 67 sources of fresh water (Po river included). The exchange of data between models it is set to happen every 1O minutes of model time. The exchange is two-ways, therefore each component of the system influences the dynamics of the other components. In order to resolve the coastal dynamics, the oceanographic component above described was also used as parent grid for a one-way nested grid covering the area of sea facing the Marche rigion (child grid) with an horizontal resolution of 200 m. In this effort, the model system validation and results from a case study will be presented. The impact of the ocean-atmosphere coupling will be briefly addressed by comparing results with the ones obtained by a weather forecast (no coupled) and an ocean forecast (only ROMS+SWAN coupling). While the capability of the system in resolving the coastal dynamics is it assessed comparing results from the parent grid and results from the child grid with observed data.