Index Catalog // ScholarsArchive@OSU

Creator:: Smyth, W. D., Nash, J. D., and Moum, J. N.
Abstract:: Direct numerical simulations are used to compare turbulent diffusivities of heat and salt during the growth and collapse of Kelvin–Helmholtz billows. The ratio of diffusivities is obtained as a function of buoyancy Reynolds number Re[subscript]b and of the density ratio R[subscript]ρ (the ratio of the contributions of heat and salt...
Resource Type:: Article

Creator:: Smyth, W. D., Moum, J. N., and Caldwell, D. R.
Abstract:: The time evolution of mixing in turbulent overturns is investigated using a combination of direct numerical simulations (DNS) and microstructure profiles obtained during two field experiments. The focus is on the flux coefficient Γ, the ratio of the turbulent buoyancy flux to the turbulent kinetic energy dissipation rate ϵ. In...
Resource Type:: Article

Creator:: Smyth, W. D., Moum, J. N., and Nash, J. D.
Abstract:: Narrowband oscillations observed in the upper equatorial Pacific are interpreted in terms of a random ensemble of shear instability events. Linear perturbation analysis is applied to hourly averaged profiles of velocity and density over a 54-day interval, yielding a total of 337 unstable modes. Composite profiles of mean states and...
Resource Type:: Article

Creator:: Moum, J. N., Klymak, J. M., Nash, J. D., Perlin, A., and Smyth, W. D.
Abstract:: Winter stratification on Oregon’s continental shelf often produces a near-bottom layer of dense fluid that acts as an internal waveguide upon which nonlinear internal waves propagate. Shipboard profiling and bottom lander observations capture disturbances that exhibit properties of internal solitary waves, bores, and gravity currents. Wavelike pulses are highly turbulent...
Resource Type:: Article

Creator:: Moum, J. N., Farmer, D. M., Shroyer, E. L., Smyth, W. D., and Armi, L.
Abstract:: A single nonlinear internal wave tracked more than 100 wavelengths across Oregon’s continental shelf over a 12-h period exhibited nearly constant wave speed, c = 0.75 m s⁻¹, and amplitude, a = 15 m. The wavelength L gradually decreased from 220 m in 170-m water depth to 60 m in...
Resource Type:: Article

Creator:: Smyth, W. D. and Moum, J. N.
Abstract:: Deep cycle mixing in the cold tongue of the equatorial Pacific Ocean is associated with a mean flow regime in which the gradient Richardson number Ri (a ratio of stratification to shear that affects the evolution of turbulence) fluctuates about a critical value near 1/4. This is the state of...

Creator:: Smyth, W. D. and Moum, J. N.
Abstract:: Deep cycle mixing in the cold tongue of the equatorial Pacific Ocean is associated with a mean flow regime in which the gradient Richardson number Ri (a ratio of stratification to shear that affects the evolution of turbulence) fluctuates about a critical value near 1/4. This is the state of...

Creator:: Smyth, W. D., Durland, T. S., and Moum, J. N.
Abstract:: Shipboard current measurements in the equatorial Indian Ocean in October and November of 2011 revealed oscillations in the meridional velocity with amplitude ~0.10 m/s. These were clearest in a layer extending from ~300 to 600 m depth and had periods near 3 weeks. Phase propagation was upward. Measurements from two...
Resource Type:: Article

Creator:: Smyth, W. D. and Moum, J. N.
Abstract:: Deep cycle mixing in the cold tongue of the equatorial Pacific Ocean is associated with a mean flow regime in which the gradient Richardson number Ri (a ratio of stratification to shear that affects the evolution of turbulence) fluctuates about a critical value near 1/4. This is the state of...
Resource Type:: Article

Creator:: Smyth, W. D., Moum, J. N., Li, L., and Thorpe, S. A.
Abstract:: A new theory of shear instability in a turbulent environment is applied to eight days of velocity and density profiles from the upper-equatorial Pacific. This period featured a regular diurnal cycle of surface forcing, together with a clear response in upper-ocean mixing. During the day, a layer of stable stratification...
Resource Type:: Article

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