The Mediterranean outflow splitting—a comparison between theoretical models and CANIGO data

The Mediterranean outflow in the Atlantic is vertically subdivided into two main cores that are identified by temperature and salinity maxima. Hydrological data collected west of the Strait of Gibraltar and off the south and south-west coasts of Portugal in September 1997 have been used in two different models to shed some light on the mechanisms that cause a splitting of the Mediterranean outflow. These models are (i) a steady, one-dimensional streamtube model, and (ii) a local, time-dependent model that includes cross-stream variations. The streamtube model, applied at the northern, respectively, the southern part of the outflow, appears capable of reproducing the observed density difference between the two cores. The vertical separation, however, was underestimated. The results from the local model suggest that a bump in the bottom topography may be a determining factor for the splitting tendency of the flow