Mooring (oceanography)

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.

A mooring in

Lagrangian drifter
.

Construction principle

The mooring is held up in the water column with various forms of buoyancy such as

acoustic Doppler current profilers or deprecated rotor current meters), and biological sensors to measure various parameters. Long-term moorings can be deployed for durations of two years or more, powered with alkaline or lithium battery packs
.

Components

Top buoy

WHOI moored surface buoy with meteorological sensors and satellite transmitters[1]

Surface buoys

Moorings often include surface buoys that transmit real time data back to shore. The traditional approach is to use the

Argos System. Alternatively, one may use the commercial Iridium satellites
which allow higher data rates.

Syntactic foam sphere used as a subsurface float

Submerged buoys

In deeper waters, areas covered by

concrete block
or small portable anchor.

The buoyancy of the floats, i.e. of the top buoy plus additional packs of glass bulbs of foam, is sufficient to carry the instruments back to the surface. In order to avoid entangled ropes, it has been practical to place additional floats directly above each instrument.

Instrument housing

Prawlers

Prawlers (profiling crawlers) are sensor bodies which climb and descend the cable, to observe multiple depths. The energy to move is "free," harnessed by ratcheting upward via wave energy, then returning downward via gravity.[2]

Depth correction

Similar to a kite in the wind, the mooring line will follow a so-called (half-)catenary. The influence of

km), the instrument position may vary up to 50 m
.

See also

References

  1. ^ Toole, John M.; McCartney, Michael S.; Hogg, Nelson; Weller, Robert A. (2000). "Outposts in the Ocean". Oceanus Magazine. 42 (1). Woods Hole Oceanographic Institution.
  2. ^ "Prawlers, Engineers, and the Future of Oceanography at Sea. Retrieved 27 Jan 2013". 5 October 2012.
  3. ^ Dewey, Richard K. "Mooring Design & Dynamics - A Matlab Package for Designing and Testing Oceanographic Moorings And Towed Bodies". Centre for Earth and Ocean Research, University of Victoria. Archived from the original on 2013-10-12. Retrieved 2012-09-25.
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