On the unsteady response of an oceanic front to local atmospheric forcing

Abstract

Abstract : The unsteady response of two oceanic density fronts to local atmospheric forcing, using combinations of wind stress and surface heat flux, is investigated with an embedded mixed layer-general circulation model. The adjustment of the frontal structure is dependent upon the wind stress direction and whether there is surface heating or cooling. In cases of an applied wind stress alone where denser water is transported toward less dense water, the frontal structure diffuses, the mixed layer depth deepens, and cross-frontal mixing occurs. In cases where less dense water is transported toward denser water, the frontal structure is preserved, mixed layer depth is preserved and cross-frontal mixing is minimized. The addition of surface heating shallows the mixed layer and inhibits vertical mixing. Inertial oscillations are observed in the across-front velocity field.