A linear primitive equations model is used to simulate spin-up of a two-layer ocean bisected by a meridional ridge. The ocean is forced with steady zonal winds east of the ridge. When wind-driven barotropic planetary Rossby waves propagate across the ridge, barotropic and baroclinic anomalies are generated as the barotropic flow adjusts. These ridge-generated anomalies propagate westward from the ridge as planetary Rossby waves and their arrival along the basin's western boundary modulates the western boundary current (WBC) transport and vertical structure. Model results suggest that at short (<1 year) and long (>10 years) delay relative to a change in wind stress curl, net WBC transport, TWBC, is that predicted by the Sverdrup balance for a flat ocean, TSv, but at intermediate delay this balance is disrupted by arrival of the additional barotropic ridge-generated anomalies. The magnitude of the anomalous transport, TWBC, depends on the meridional deflection of the flow at the ridge relative to the length-scale over which wind stress curl varies. The timescale, tBT, associated with adjustment at the ridge is a function of latitude, density contrast between layers and ridge width.
Andres, Magdalena, Jiayan Yang, and Young-Oh Kwon. 2012. "Adjustment of a wind-driven two-layer system with mid-basin topography." Journal of Marine Research 70, (6). https://elischolar.library.yale.edu/journal_of_marine_research/362