scholarly journals Spatial Variation of Diapycnal Diffusivity Estimated From Seismic Imaging of Internal Wave Field, Gulf of Mexico

2017 ◽  
Vol 122 (12) ◽  
pp. 9827-9854 ◽  
Author(s):  
Alex Dickinson ◽  
N. J. White ◽  
C. P. Caulfield
Keyword(s):  
Gulf Of Mexico ◽  
Internal Wave ◽  
Spatial Variation ◽  
Wave Field ◽  
Seismic Imaging ◽  
Internal Wave Field ◽  
Diapycnal Diffusivity

scholarly journals Internal Waves and Turbulence in the Antarctic Circumpolar Current

2013 ◽  
Vol 43 (2) ◽  
pp. 259-282 ◽  
Author(s):  
Stephanie Waterman ◽  
Alberto C. Naveira Garabato ◽  
Kurt L. Polzin
Keyword(s):  
Internal Wave ◽  
Wave Field ◽  
Dissipation Rate ◽  
Antarctic Circumpolar Current ◽  
Wave Radiation ◽  
Turbulent Dissipation ◽  
Internal Wave Field ◽  
Diapycnal Diffusivity ◽  
Circumpolar Current ◽  
The Antarctic

Abstract This study reports on observations of turbulent dissipation and internal wave-scale flow properties in a standing meander of the Antarctic Circumpolar Current (ACC) north of the Kerguelen Plateau. The authors characterize the intensity and spatial distribution of the observed turbulent dissipation and the derived turbulent mixing, and consider underpinning mechanisms in the context of the internal wave field and the processes governing the waves’ generation and evolution. The turbulent dissipation rate and the derived diapycnal diffusivity are highly variable with systematic depth dependence. The dissipation rate is generally enhanced in the upper 1000–1500 m of the water column, and both the dissipation rate and diapycnal diffusivity are enhanced in some places near the seafloor, commonly in regions of rough topography and in the vicinity of strong bottom flows associated with the ACC jets. Turbulent dissipation is high in regions where internal wave energy is high, consistent with the idea that interior dissipation is related to a breaking internal wave field. Elevated turbulence occurs in association with downward-propagating near-inertial waves within 1–2 km of the surface, as well as with upward-propagating, relatively high-frequency waves within 1–2 km of the seafloor. While an interpretation of these near-bottom waves as lee waves generated by ACC jets flowing over small-scale topographic roughness is supported by the qualitative match between the spatial patterns in predicted lee wave radiation and observed near-bottom dissipation, the observed dissipation is found to be only a small percentage of the energy flux predicted by theory. The mismatch suggests an alternative fate to local dissipation for a significant fraction of the radiated energy.

scholarly journals The internal wave field in Sau reservoir: Observation and modeling of a third vertical mode

2005 ◽  
Vol 50 (4) ◽  
pp. 1326-1333 ◽  
Author(s):  
Javier Vidal ◽  
Xavier Casamitjana ◽  
Jordi Colomer ◽  
Teresa Serra
Keyword(s):  
Internal Wave ◽  
Wave Field ◽  
Vertical Mode ◽  
Internal Wave Field

scholarly journals Internal Waves and Mixing near the Kerguelen Plateau

2015 ◽  
Vol 46 (2) ◽  
pp. 417-437 ◽  
Author(s):  
Amelie Meyer ◽  
Kurt L. Polzin ◽  
Bernadette M. Sloyan ◽  
Helen E. Phillips
Keyword(s):  
Internal Wave ◽  
Wave Field ◽  
Internal Waves ◽  
Large Scale ◽  
Polar Front ◽  
Frontal Region ◽  
Small Scale ◽  
Kerguelen Plateau ◽  
Flow Strength ◽  
Internal Wave Field

AbstractIn the stratified ocean, turbulent mixing is primarily attributed to the breaking of internal waves. As such, internal waves provide a link between large-scale forcing and small-scale mixing. The internal wave field north of the Kerguelen Plateau is characterized using 914 high-resolution hydrographic profiles from novel Electromagnetic Autonomous Profiling Explorer (EM-APEX) floats. Altogether, 46 coherent features are identified in the EM-APEX velocity profiles and interpreted in terms of internal wave kinematics. The large number of internal waves analyzed provides a quantitative framework for characterizing spatial variations in the internal wave field and for resolving generation versus propagation dynamics. Internal waves observed near the Kerguelen Plateau have a mean vertical wavelength of 200 m, a mean horizontal wavelength of 15 km, a mean period of 16 h, and a mean horizontal group velocity of 3 cm s−1. The internal wave characteristics are dependent on regional dynamics, suggesting that different generation mechanisms of internal waves dominate in different dynamical zones. The wave fields in the Subantarctic/Subtropical Front and the Polar Front Zone are influenced by the local small-scale topography and flow strength. The eddy-wave field is influenced by the large-scale flow structure, while the internal wave field in the Subantarctic Zone is controlled by atmospheric forcing. More importantly, the local generation of internal waves not only drives large-scale dissipation in the frontal region but also downstream from the plateau. Some internal waves in the frontal region are advected away from the plateau, contributing to mixing and stratification budgets elsewhere.

Sign in / Sign up

Export Citation Format

Share Document