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Tidal Asymmetry in an Estuarine Pycnocline: Depth and Thickness
Journal of Geophysical Research
  • Cynthia N. Cudaback, Marine Science Institute
  • David A. Jay, Portland State University
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Publication Date
  • Columbia River Estuary (Or. and Wash.) -- Internal waves,
  • Columbia River Estuary (Or. and Wash.) -- Tides -- Analysis
Tidal variations in estuarine stratification are revealed by the depth and thickness of the density interface. The depth of the interface may be predicted using an inviscid two-layer model that combines baroclinic estuarine circulation with barotropic tidal currents [Helfrich, 1995]. Here we present results from a two-layer model modified to include the effects of bottom friction and interfacial mixing. Modeled layer thickness and speed compare favorably with prior analytic studies [Farmer and Armi, 1986; Pratt, 1986]. We use a bulk Richardson number criterion to estimate the thickness of the pycnocline from two-layer model results; the predicted pycnocline depth and thickness compare remarkably well with observations. We also investigate the effects of changing bottom friction and barotropic currents on the pycnocline thickness.

This is the publisher's final PDF. Copyright 2000 American Geophysical Union

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Citation Information
Cudaback, C. N., and D. A. Jay (2000), Tidal asymmetry in an estuarine pycnocline: Depth and thickness, J. Geophys. Res., 105(C11), 26,237–26, 251.