Trapping of a coastal density front by the bottom boundary layer

Abstract

The dynamics of a surface-to-bottom density front on a uniformly sloping continental shelf and the role of density advection in the bottom boundary layer are examined using a three-dimensional, primitive equation numerical model. The front is formed by prescribing a localized freshwater inflow through the coastal boundary. The location of the trapped front is consistent with simple thermal wind dynamics. The basic frontal-trapping mechanism dominates the dynamics for a wide range of inflow velocities and densities (including very weak density anomalies), indicating that the advection of density in the bottom boundary layer may play a major role in the circulation on many continental shelves, even when the bottom boundary layer is thin compared to the total water depth. -from Authors