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2 edition of Dynamics of Langmuir circulation in oceanic surface layers found in the catalog.

Dynamics of Langmuir circulation in oceanic surface layers

Anand Gnanadesikan

Dynamics of Langmuir circulation in oceanic surface layers

by Anand Gnanadesikan

  • 294 Want to read
  • 27 Currently reading

Published by Woods Hole Oceanographic Institution in Woods Hole, Mass .
Written in English

    Subjects:
  • Ocean circulation.,
  • Oceanic mixing.

  • Edition Notes

    Statementby Anand Gnanadesikan.
    SeriesWHOI / Woods Hole Oceanographic Institution -- 94-23., WHOI (Series) -- 94-23.
    The Physical Object
    Pagination350 p. :
    Number of Pages350
    ID Numbers
    Open LibraryOL15400734M

    tect. Hence wave dynamics, not viscous and diffusive pro-cesses, can determine the surface boundary fluxes of mo-mentum, energy, andscalars, andultimatelythe vertical mix-ing of the oceanic boundary layer (OBL). The considerable complexity exhibited in Figure 1 is replaced, by conven-tion and presumed necessity, in most 1-D oceanicboundary-. affected by Langmuir circulation. These results are in agreement with a conclusion inferred from a recent analysis of the near-surface turbulence measurements at the CBLAST site. Citation: Li, S., M. Li, G. P. Gerbi, and J.-B. Song (), Roles of breaking waves and Langmuir circulation in the surface boundary layer of a coastal ocean, J.

    Langmuir Circulation One final type of wind-driven surface current occurs on a smaller scale when the winds blow in a consistent direction at relatively high speeds. Underneath these strong winds, water flows in a series of parallel corkscrew patterns called Langmuir cells (Figure top). Each of the cells may be several meters wide and.   POM-gcs (Ezer and Mellor, ), a branch of the Princeton Ocean Model (POM; Blumberg and Mellor, ), is utilized to simulate the circulation in Bohai version of POM adopts a generalized sigma-coordinate system and in the hierarchy of free surface and 3D primitive equation. The level Mellor-Yamada turbulence closure scheme is included in POM-gcs to .

    Partial contents: Structures and fluxes in a deep convecting mixed layer; Equatorial turbulence--Mixed layer and thermocline; Zonal momentum balance at the equator; The mixed layer of the western equatorial Pacific Ocean; Observations of ocean waves and Langmuir circulation with Doppler sonars; Unsteady shallowing mixed layer; Some effects of heating on the wind-driven velocity in the upper. The clumps of floating algae are often concentrated by the strong winds and wave action associated with the Gulf Stream. In physical oceanography, Langmuir circulation consists of a series of shallow, slow, counter-rotating vortices at the ocean's surface aligned with the wind.


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Dynamics of Langmuir circulation in oceanic surface layers by Anand Gnanadesikan Download PDF EPUB FB2

(PDF) Dynamics of Langmuir Circulation in Oceanic Surface Layers. | Anand Gnanadesikan - Abstract: This work investigates whether large-scale coherent vortex structures driven by wave-current interaction (Langmuir circulation) are responsible for maintaining the oceanic mixed layer.

Langmuir circulations dominate the near-surface. Langmuir circulations dominate the near-surface vertical transport of momentum and density when the characteristic scale for forcing (defined as the Craik-Leibovich instability parameter gamma_{rm CLS }) is stronger than the characteristic scale for diffusive decay gamma_{rm diff}.Cited by: 4.

The vertical structure of the oceanic surface boundary layer and the role of Langmuir circulation in its evolution have been elucidated by analysis of field observations from the Surface Waves. Enter the password to open this PDF file: Cancel OK.

File name:. Until the s, a tacit agreement among many physical oceanographers was that nothing deserving attention could be found in the upper few meters of the ocean. The lack of adequete knowledge about the near-surface layer of the ocean was mainly due to the fact that the widely used oceanographic instruments (such as bathythermographs, CTDs, current meters, etc.) were practically useless in the 4/5(1).

Leibovich and S. Paolucci, The Langmuir circulation instability as a mixing mechanism in the upper ocean. Phys. Ocean. 10, (). CrossRef Google Scholar. Langmuir circulation within the oceanic mixed layer near-surface layer of the ocean, LANGMUIR () carried out a series of flow visualiza- in the mixed layer and thus whether or not it played a significant role in upper ocean dynamics.

More widely accepted was the notion that small scale turbulence was the. Langmuir circulations are coherent structures within the mixed layer that produce counter rotating vortices with axes aligned parallel to the wind. Their surface signature is familiar as windrows: lines of bubbles and surface debris aligned with the wind that mark the convergence zones between the vortices.

Abstract Large-eddy simulation of the oceanic mixed layer showed that Langmuir circulation (LC) is weakened under the surface heating and is ultimately broken down if the intensity of the surface heating becomes sufficiently strong. III. Potential Importance of Langmuir Circulation The ocean surface acts as a filter on ocean-atmosphere communication of momentum, energy, and chemical tracers (e.g., C02) and is the region where phytoplankton can grow.

As a result, it is important to accurately model and parameterize unresolved scales in this turbulent region. It is. The oceanic surface mixed layer is a crucial link in coupling the air and sea.

The of these dynamics, and one which dominates the observed kinematics, is a pattern Woodcock suggested that oceanic Langmuir circulation may be asymmetric (Woodcock ). Some evidence for the validity of the parameterization is found, thus drawing attention to Langmuir's assertion that Langmuir circulation is one of the key physical processes in the oceanic boundary layer.

The third aspect of surface boundary layer dynamics explored is the mean effect on mixed layer entrainment of periodic vertical movement of isopycnals in the thermocline due to non-breaking internal waves (referred to as heaving).

Since the Langmuir circulation is a characteristic phenomenon with a zonal and a circulation cell structure in the sea surface layer (Leibovich ; Thorpe ), Langmuir circulation could. The interaction between wind-driven Langmuir circulation and preexisting stratification is examined in order to elucidate its role in the deepening of the ocean surface mixed layer.

For linear stratification, a numerical model suggests that Langmuir cells initially engulf water and create a homogeneous surface layer. Dynamics of Langmuir circulation in oceanic surface layers  Gnanadesikan, Anand (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, ) This work investigates whether large-scale coherent vortex structures driven by wave-current interaction (Langmuir circulation) are responsible for maintaining the.

Progress in modeling the oceanic circulation has been achieved in the last few years by increasing the speed of computers and by refining modeling techniques. The dynamics of major current systems such as the Gulfstream-North Atlantic Current and their corresponding eddy variability is reasonably well understood [58, 32].

Some reports of Langmuir circulations describe windrows at systematic angles to the local wind direction. Other observers find windrows in close alignment to the wind direction, but with a systemat.

In physical oceanography, Langmuir circulation consists of a series of shallow, slow, counter-rotating vortices at the ocean's surface aligned with the wind.

These circulations are developed when wind blows steadily over the sea surface. Irving Langmuir discovered this phenomenon after observing windrows of seaweed in the Sargasso Sea in When E [Lt ] 1, the Langmuir mode dominates.

When E [Gt ] 1, inertial motion results. The classical Ekman drift current is a special case even under the restriction E ≃ 1. On the basis of these results, a new model of the surface-layer movements for future large-scale ocean circulation studies is presented.

Noh, Yign Ok, Hyejin Lee, Eunjeong Toyoda, Takahiro and Hirose, Naoki Parameterization of Langmuir Circulation in the Ocean Mixed Layer Model Using LES and Its Application to the OGCM. Journal of Physical Oceanography, Vol. 46, Issue. 1, p. CrossRef; Google Scholar.

Where would Ekman layers be contained within the winter surface mixed layer and where would they extend below it? 4. Compare the timescales of surface waves, Langmuir circulation, inertial circulation and a fully-developed Ekman layer.

Study calculation A steady wind field is blowing on a rectangular ocean basin km wide.Initiative (DRI) on “Waves, Langmuir Cells, and the Upper Ocean Boundary Layer” is to un­ cover the fundamental dynamics that connect motions on scales ranging from 1 m to 10 km in the upper ocean.

OBJECTIVES. Our primary objective is to understand how surface boundary layer .LC (5) The Langmuir circulations must have maximum downwelling speeds comparable to the mean wind-directed surface drift.

These still constitute a minimal checklist against which to compare a theory. Figure 1 b Aerial photograph of oil bands in the Gulf Mexico collected by Langmuir­ circulation sweeping of the surface.