Sensitivity analysis of a robust diagnostic general circulation model of the Ross Sea

The work aims to explore the sensitivity response of a robust-diagnostic model of the Ross Sea area to different forcings and boundary conditions. Numerical experiments using different open boundary velocities, wind stress fields, constraints for sea surface elevation, objectively analyzed or constant ad hoc thermohaline fields with different relaxation coefficients are proposed. Results show that realistic patterns and velocities in the basin are induced mainly by the wind forcing, while its variability can explain part of the modulation of the current field observed but does not affect significantly the Ross island recirculation, mainly controlled by the thermohaline field. The in–out flow below the Ross Ice Shelf (RIS) is influenced by the assumptions adopted for the Sea Surface Elevation along the shelf itself, while the wind variability can explain the exchange between the RIS cavity and the sea. Even if the model has to be improved, especially for what concerns the sea–ice interactions that are not present in this version, comparisons between current meters moorings data averages and reconstructed fields show that features can be explained by wind stress variability, while circulation patterns are in good agreement with experimental observations and other theoretical studies.