FY 1995

Stress on the Mediterranean outflow plume: Part II. Turbulent dissipation and shear measurements

Johnson, G.C., R.G. Lueck, and T.B. Sanford

J. Phys. Oceanogr., 24(10), 2084–2092, doi: 10.1175/1520-0485(1994)024<2084:SOTMOP>2.0.CO;2 (1994)

Bottom and interfacial stresses on the Mediterranean outflow plume are estimated using vertical profiles of turbulent dissipation and velocity collected in the Gulf of Cadiz. Turbulent dissipation is high throughout the plume, with a local minimum often present near the plume nose (depth of maximum downstream velocity). Bottom stresses are estimated by applying a log-layer model to the dissipation measurements. The dissipation measurements are also divided by plume-scale vertical shear from the horizontal velocity profiles to construct profiles of stress within the plume. The mean stress estimates in the bottom layer agree well with those calculated in the log layer from the dissipation measurements alone. The bottom-layer means are slightly larger than those of the interfacial layer. The maximum stresses in each layer are uncertain, since they depend on the ill-defined shape of the stress profiles within the plume. Dissipation-derived stress estimates in the log layer and those from dissipation measurements combined with the plume-scale vertical shear of horizontal velocity are roughly one-third the magnitude of those made in the log layer from velocity measurements and those made in the interfacial layer from the residuals of bulk mass and volume budgets (Part I). Possible reasons for this discrepancy are advanced.