Langmuir circulation

Figures 6 and 7 show a modem Langmuir film balance and its arrangement inside a Puffer-Hubbard temperature-controlled cabinet (63). Inside the cabinet, the film balance is protected further from circulating air currents by a Plexiglass case. At the bottom of the Teflon trough lies a serpentine glass coil through which water from a thermoregulator is circulated to help control subphase temperature.

Ledbetter, M., Langmuir circulations and plankton patchiness , Ecol. Modeling, 7,289-310 (1979). 

Scott, J.T., Myer, G.E., Stewart, R. and Walther, E.G. On the mechanism of Langmuir circulations and their role in epilimnion mixing. Limnol. Oceanogr. 14, 493-503 (1969). 

Langmuir circulations that produce the lines are thought to extend that deep into the sea. The little-understood coupling between the sea and the air can produce circulations that transport organic material to the surface and compress it into visible slicks that form lines parallel to the wind. A detailed review of the dynamics of Langmuir circulations can be found in a paper by Faller (48). 

Relations between Wind Speed, Langmuir Circulation and Particle Circulation in the Ocean, Deep-Sea Res. (1971) 18, 639-643. 

An alternative perspective is the assumption that the Reynolds stress is an external function of time and depth described as a volume force independent of the mean current (Pollard, 1970). Such a conceptual model is valid if the turbulence generating the Reynolds stress in the surface mixed layer is caused by physical mechanisms that are independent of the mean current. Pollard (1977) suggested that Langmuir circulation might by a very effective mechanism to distribute Reynolds stress downward in the surface mixed layer from the sea surface where all the momentum is received from the wind stress. 

A refined one-dimensional numerical ocean model of the southern Baltic Sea was used by Axell (2002) to investigate suitable parameterizations of unresolved turbulence and compared it with available observations. The turbulence model is a k- model that includes extra source terms of turbulent kinetic energy production by internal waves and Langmuir circulation due to unresolved, breaking internal waves and Langmuir... 

Axell, L. B., 2002. Wind-driven internal waves and Langmuir circulations in a numerical ocean model of the southern Baltic Sea. Journal of Geophysical Research, 107 (Cl 1), 3204, doi 10.1029/ 2001JC000922. 

Figure 5. Results of a model for inhibition of photosynthesis in the surface layer of the Weddell-Scotia Confluence of the Southern Ocean (modified from Neale et al. [70]). (a) Interactive effects of mixing depth and mixing time scale on daily water column productivity relative to the uninhibited rate (curves labeled with t ,ix = time scale of mixing). Langmuir circulation can mix the upper water column rapidly, so mixing times < 1 h are modeled for mixing depths <42 m. (b) Interactive effects of O3 depletion (150 DU vs 300 DU) and mixing time as a function of mixing depth proportional change in Pj for the same curves as in (a).

M. Li, C. Garrett (1997). Mixed layer deepening due to Langmuir circulation. J. Phys. 

Melville WK, Shear R, Veron F (1998) Laboratory measurements of the generation and evolution of Langmuir circulations. J Fluid Mech 364 31-58... 

When a reaction takes place by a redox mechanism, other reactions may take place at the same time by Langmuir-Hinshelwood or Eley-Rideal mechanisms or by homogeneous reactions. These other reactions could be eliminated or minimized by using two reactors, one fed with air or oxygen and the other fed with reactant A. The catalyst would be circulated between the two units using moving-bed or fluidized-bed technology. 

Fig. 1. Processes that influence transfer of gases across the natural air-water interface. Some of these include wind shear, waves, Langmuir circulation, turbulent mixing, and bubbles injected by breaking waves. In addition, films of organic surface active materials reduce direct gas transfer through the air water interface and through bubble surfaces...

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