Modelling the marine circulation of the Campania coastal system (Tyrrhenian Sea) for the year 2016: Analysis of the dynamics.

The Campania coastal system (CCS), located in the Tyrrhenian Sea, is characterized by an interesting and complex morphology, being made by a sequence of three gulfs (Gaeta, Naples and Salerno, GG, GN, GS) of different sizes, shapes, and bathymetries. Until now, most of the oceanographic studies in the area have focused on the GN, whereas little is known about the circulation in the GG and GS. Here, for the first time, a high-resolution modelling study of the whole CCS has been carried out, which covers a whole year (2016), allowing for a detailed description of the seasonal variability throughout this year. For each season, the dynamics in the three gulfs have been characterized, assessing the relative roles of the wind forcing, the topographic constraints and the remote large-scale Tyrrhenian Sea circulation. As a first step, the surface circulation patterns in the CCS have been compared with altimeter observations and with the atmospheric forcing. A detailed analysis of the monthly mean surface and intermediate circulation within each gulf has then been performed. Besides, a more quantitative insight into the mechanisms controlling the circulation has been obtained using an integrated vorticity diagnostic, which allows one to separate different contributions to the total barotropic vorticity equation. The results show a strong seasonality of the circulation in the three gulfs, which is mainly controlled by the wind stress input during autumn and winter, whereas in spring and summer the main contribution comes from the combined effect of baroclinicity and topographic gradient (the JBAR term). The exchanges between the gulfs and the Tyrrhenian waters have also been quantified, through the analysis of the transport across specific sections. These transports are found to be highly correlated with the offshore large-scale circulation in the GG, whereas in the GS there is strong correlation with the local wind forcing. Finally, lower correlations are found for the more geometrically complex and semi-enclosed GN. • The marine circulation of the Campania Coastal System is simulated for the year 2016. • This is done with a local high-resolution model nested with a Mediterranean NEMO. • Dynamical investigation based on a vorticity and transport diagnostics is performed. • The relative role of the atmospheric and remote Tyrrhenian forcings is assessed. [ABSTRACT FROM AUTHOR]