Development of an atmosphere-ocean coupled model and its application over the Adriatic Sea during a severe weather event of Bora wind

This study presents the results of an application to a Bora severe weather episode (January 1995) in the northern Adriatic Sea of the regional two-way atmosphere-ocean coupled model (RAMS-DieCAST), developed jointly by the Università di Torino and the Istituto Sperimentale Talassografico del CNR, Trieste. RAMS-DieCAST showed significantly better ability to predict the sea surface temperature (SST) and its time evolution during the above mentioned episode using a full two-way coupling as opposed to simpler one-way forcing of the ocean. In this context, we found out that even in the high-frequency variability conditions that are typical of Bora events, heat fluxes from the sea must be taken into account for a better description of air-sea interaction processes in a dynamical framework. The SST evolution has been chosen as a validation parameter, owing to its availability and relevance for the characterization of the marine environment and local weather and climate studies. The simulations carried out with RAMS-DieCAST present a small systematic error in calculating the SST evolution; however, a sensitivity analysis of the model to the preparation of initial conditions of the simulation suggested that climatological initialization could be partly responsible for this error, which might be reduced by assimilating satellite-derived SSTs into the preparation of the initial conditions of the model.