Calculating Reynolds stresses from ADCP measurements in the presence of surface gravity waves using the cospectra-fit method
Kirincich, Anthony R.
Lentz, Steven J.
Gerbi, Gregory P.
MetadataShow full item record
Recently, the velocity observations of acoustic Doppler current profilers (ADCPs) have been successfully used to estimate turbulent Reynolds stresses in estuaries and tidal channels. However, the presence of surface gravity waves can significantly bias stress estimates, limiting application of the technique in the coastal ocean. This work describes a new approach to estimate Reynolds stresses from ADCP velocities obtained in the presence of waves. The method fits an established semiempirical model of boundary layer turbulence to the measured turbulent cospectra at frequencies below those of surface gravity waves to estimate the stress. Applied to ADCP observations made in weakly stratified waters and variable significant wave heights, estimated near-bottom and near-surface stresses using this method compared well with independent estimates of the boundary stresses in contrast to previous methods. Additionally, the vertical structure of tidal stress estimated using the new approach matched that inferred from a linear momentum balance at stress levels below the estimated stress uncertainties. Because the method makes an estimate of the horizontal turbulent length scales present as part of the model fit, these results can also enable a direct correction for the mean bias errors resulting from instrument tilt, if these scales are long relative to the beam separation.
Author Posting. © American Meteorological Society, 2010. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Atmospheric and Oceanic Technology 27 (2010): 889-907, doi:10.1175/2009JTECHO682.1.
Showing items related by title, author, creator and subject.
Measurements and models of fine-structure, internal gravity waves and wave breaking in the deep ocean Eriksen, Charles C. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1976-09)Measurements of horizontal and vertical current by propeller cluster current meters and temperature by thermistors mounted on a rigid array 8 m high and 20 m long moored in the oceanic main thermocline near Bermuda are ...
Joyce, Terrence M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1972-06)A laboratory study has been undertaken to measure the momentum transfer from surface to internal gravity waves in a nonlinear, resonant interaction. The interacting waves form triads for which σ1s - σ2s ± σI = 0 and κ1s - ...
Three-dimensional acoustic propagation through shallow water internal, surface gravity and bottom sediment waves Shmelev, Alexey A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2011-09)This thesis describes the physics of fully three-dimensional low frequency acoustic interaction with internal waves, bottom sediment waves and surface swell waves that are often observed in shallow waters and on continental ...