Woods Hole Oceanographic Institution

Claudia Cenedese

»Downwelling in Basins Subject to Buoyancy Loss
»Entrainment and mixing dynamics of surface-stress-driven stratifi ed flow in a cylinder
»Laboratory experiments on two coalescing axisymmetric turbulent plumes in a rotating fluid
»Impact of fjord dynamics and glacial runoff on the circulation near Helheim Glacier
»The relationship between flux coefficient and entrainment ratio in density currents
»A new parameterization for entrainment in overflows
»Laboratory experiments on the interaction of a buoyant coastal current with a canyon: application to the East Greenland Current
»Variations in ocean surface temperature due to near surface flow: straining the cool skin layer
»Mixing in a density-driven current flowing down a slope in a rotating fluid
»Laboratory experiments on mesoscale vortices colliding with an island chain
»Laboratory observations of enhanced entrainment in dense overflows in the presence of submarine canyons and ridges
»How entraining density currents influence the stratification in a one-dimensional ocean basin
»Laboratory experiments on eddy generation by a buoyant coastal current flowing over variable bathymetry
»Laboratory experiments on mesoscale vortices interacting with two islands
»Variability of Antarctic bottom water flow into the North Atlantic
»Laboratory experiments on a mesoscale vortex colliding with topography of varying geometry in a rotating fluid
»A laboratory model of thermocline depth and exchange fluxes across circumpolar fronts
»A dense current flowing down a sloping bottom in a rotating fluid
»Laboratory experiments on mesoscale vortices colliding with a seamount
»Stability of a buoyancy-driven coastal current at the shelf break
»Eddy-shedding from a boundary current around a cape over a sloping bottom
»Cyclone and anticyclone asymmetry in a rotating stratified fluid over bottom topography

Shravat A., Cenedese C. and Caulfield C.P., Entrainment and mixing dynamics of surface-stress-driven stratifi ed flow in a cylinder, Submitted to J. Fluid Mech., 2011

We extend previous work of Boyer, Davies & Guo (1997) to consider the evolution of an initially two-layer stratifi ed fluid in a cylindrical tank which is driven by a horizontal rotating disc. The turbulent motions induced by the disc drive entrainment at the interface, and similarly to the results of Boyer et al. (1997), the layer nearer to the disc deepens. Through high-frequency conductivity probe measurements, we establish that the deepening layer is very well-mixed, and the depth of the interface between the two evolving layers appears to be approximately constant. Under certain circumstances, we find that the rate of increase in depth of the deepening layer decreases with time, at variance with the results of Boyer et al., (1997) and implying that the characteristic velocities in the deepening layer decrease as the upper layer deepens. We propose that such time-dependent deepening, and the associated weakening of the upper layer velocities, occurs naturally because of the combined power requirements of entrainment and layer homogenization which inhibit, when the stratification is very strong, the characteristic velocities of the deepening layer approaching the (constant) velocities of the driving disc, as assumed by Boyer et al. (1997).

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