Coastal Langmuir circulations induce phase-locked modulation of bathymetric stress
| Autor: | Kalyan Shrestha, William Anderson |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Langmuir
Buoyancy Langmuir Turbulence engineering.material Physics::Geophysics Physics::Fluid Dynamics Boundary layer Surface wave Downwelling engineering Environmental Chemistry Bathymetry Geomorphology Physics::Atmospheric and Oceanic Physics Geology Water Science and Technology Langmuir circulation |
| Zdroj: | Environmental Fluid Mechanics. 20:873-884 |
| ISSN: | 1573-1510 1567-7419 |
| DOI: | 10.1007/s10652-019-09727-4 |
| Popis: | The ocean boundary layer (OBL) is forced by atmosphere-ocean and sea ice-ocean momentum fluxes, wave dynamics, and buoyancy; in coastal zones, OBL dynamics are further complicated by additional shear from the seafloor. Among numerous other phenomena, coastal mixing affects dispersion of anthropogenic quantities, erosion and turbidity, and benthic sequestration. In the OBL, interaction of wind-induced shear and surface waves manifests so-called Langmuir turbulence and distinctive Langmuir cells under favorable conditions, which have implications for the aforementioned coastal processes. Large-eddy simulation was used to dynamically sample the flow during relative extremes in bathymetric stress and vertical velocity. Probability density functions of vertical velocity are bimodal, the signature of persistent upwelling and downwelling within Langmuir cells, and this attribute manifests itself in the bathymetric stress, revealing a phase-locked modulation. We report modulation between negative vertical velocity (downwelling) and relatively elevated bathymetric stresses, thereby revealing that coastal Langmuir turbulence has direct implications for erosion and turbidity. |
| Databáze: | OpenAIRE |
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