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Title: Turbulence Measurements from Compliant Moorings. Part II: Motion Correction

Acoustic Doppler velocimeters (ADVs) are a valuable tool for making high-precision measurements of turbulence, and moorings are a convenient and ubiquitous platform for making many kinds of measurements in the ocean. However, because of concerns that mooring motion can contaminate turbulence measurements and that acoustic Doppler profilers make middepth velocity measurements relatively easy, ADVs are not frequently deployed from moorings. This work demonstrates that inertial motion measurements can be used to reduce motion contamination from moored ADV velocity measurements. Three distinct mooring platforms were deployed in a tidal channel with inertial-motion-sensor-equipped ADVs. In each case, motion correction based on the inertial measurements reduces mooring motion contamination of velocity measurements. The spectra from these measurements are consistent with other measurements in tidal channels and have an f –5/3 slope at high frequencies - consistent with Kolmogorov's theory of isotropic turbulence. Motion correction also improves estimates of cross spectra and Reynolds stresses. A comparison of turbulence dissipation with flow speed and turbulence production indicates a bottom boundary layer production-dissipation balance during ebb and flood that is consistent with the strong tidal forcing at the site. Finally, these results indicate that inertial-motion-sensor-equipped ADVs are a valuable new tool for making high-precision turbulence measurementsmore » from moorings.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. Univ. of Washington, Seattle, WA (United States)
  3. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  4. Nortek AS, Rud (Norway)
Publication Date:
Report Number(s):
NREL/JA-5000-67282
Journal ID: ISSN 0739-0572
Grant/Contract Number:
AC36-08GO28308
Type:
Published Article
Journal Name:
Journal of Atmospheric and Oceanic Technology
Additional Journal Information:
Journal Volume: 34; Journal Issue: 6; Journal ID: ISSN 0739-0572
Publisher:
American Meteorological Society
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
Country of Publication:
United States
Language:
English
Subject:
16 TIDAL AND WAVE POWER; turbulence; acoustic measurements/effects; buoy observations; in situ oceanic observations; instrumentation/sensors; renewable energy
OSTI Identifier:
1364677
Alternate Identifier(s):
OSTI ID: 1373672