Influence of high-resolution wind forcing on hydrodynamic modeling of the Gulf of Lions

Abstract

The impact of the choice of high-resolution atmospheric forcing on ocean summertime circulation in the Gulf of Lions (GoL; Mediterranean Sea) is evaluated using three different datasets: AROME (2.5 km, 1 h), ALADIN (9.5 km, 3 h), and MM5 (9 km, 3 h). A short-term ocean simulation covering a 3-month summer period was performed on a 400-m configuration of the GoL. The main regional features of both wind and oceanic dynamics were well-reproduced by all three atmospheric models. Yet, at smaller scales and for specific hydrodynamic processes, some differences became apparent. Inertial oscillations and mesoscale variability were accentuated when high-resolution forcing was used. Sensitivity tests suggest a predominant role for spatial rather than temporal resolution of wind. The determinant influence of wind stress curl was evidenced, both in the representation of a mesoscale eddy structure and in the generation of a specific upwelling cell in the north-western part of the gulf.