Langmuir circulation

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The Langmuir circulation - named after Irving Langmuir  - is a form of wind-driven circulation of water.

Langmuir circulation with strips of flotsam
The light stripes on the water surface result from the roller movement of the water.

Constant wind causes cylindrical currents of 5 to 50 meters in width and depth to form parallel to the direction of the wind . Individual water particles describe a helical path in these rollers , which effectively transports them in the direction of the wind.

Between the counter-rotating currents, there are zones in which water flows together on the surface perpendicular to the wind direction (convergence) or is pushed apart (divergence).

In the convergences, organic particles and immobile organisms accumulate with positive static buoyancy . These are mainly zooplankton , nekton and pleuston . Tange , Pleuston and floating debris are gathered here on the surface of the sea. Clearly visible wind rows are formed .

Where there are divergences on the surface, i.e. the roller currents diverge, they run together again on the bottom and collect phytoplankton and organisms there that tend to sink due to downforce (negative buoyancy) in calm water.

literature

  • Jörg Ott , Sigrid Neulinger (illustrations): Oceanography . Introduction to the geography and biology of the oceans. 2nd, revised edition. UTB - Uni Taschenbuch 1450, Stuttgart 1996, ISBN 3-8252-1450-8 (first edition: 1988).
  • Jeremy Blanchard: Numerical investigations of Langmuir circulation and internal waves . Thesis, University of New Hampshire, 2008, limited preview in Google Book Search.

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