• Businger, J. A., J. C. Wyngaard, Y. Izumi, and E. F. Bradley, 1971: Flux profile relationships in the atmospheric surface layer. J. Atmos. Sci., 28 , 181189.

    • Search Google Scholar
    • Export Citation
  • Chatwin, P. C., 1976: Some remarks on the maintenance of the salinity distribution in estuaries. Estuarine Coastal Mar. Sci., 4 , 555566.

    • Search Google Scholar
    • Export Citation
  • Cheng, P., and A. Valle-Levinson, 2009: Influence of lateral advection on residual currents in microtidal estuaries. J. Phys. Oceanogr., 39 , 31773190.

    • Search Google Scholar
    • Export Citation
  • Cheng, P., R. E. Wilson, R. J. Chant, D. C. Fugate, and R. D. Flood, 2009: Modeling influence of stratification on lateral circulation in a stratified estuary. J. Phys. Oceanogr., 39 , 23242337.

    • Search Google Scholar
    • Export Citation
  • Fram, J. P., M. Martin, and M. T. Stacey, 2007: Exchange between the coastal ocean and a semi-enclosed estuarine basin: Dispersive fluxes. J. Phys. Oceanogr., 37 , 16451660.

    • Search Google Scholar
    • Export Citation
  • Fugate, D. C., C. T. Friedrichs, and L. P. Sanford, 2007: Lateral dynamics and associated transport of sediment in the upper reaches of a partially mixed estuary, Chesapeake Bay, USA. Cont. Shelf Res., 27 , 679698.

    • Search Google Scholar
    • Export Citation
  • Haidvogel, D. B., H. G. Arango, K. Hedstrom, A. Beckmann, P. Malanotte-Rizzoli, and A. F. Shchepetkin, 2000: Model evaluation experiments in the North Atlantic basin: Simulations in nonlinear terrain-following coordinates. Dyn. Atmos. Oceans, 32 , 239281.

    • Search Google Scholar
    • Export Citation
  • Hansen, D. V., and M. Rattray, 1965: Gravitational circulation in straits and estuaries. J. Mar. Res., 23 , 104122.

  • Hetland, R. D., and W. R. Geyer, 2004: An idealized study of the structure of long, partially mixed estuaries. J. Phys. Oceanogr., 34 , 26772691.

    • Search Google Scholar
    • Export Citation
  • Huijts, K. M. H., H. M. Schuttelaars, H. E. de Swart, and C. T. Friedrichs, 2009: Analytical study of the transverse distribution of along-channel and transverse residual flows in tidal estuaries. Cont. Shelf Res., 29 , 89100.

    • Search Google Scholar
    • Export Citation
  • Ianniello, J. P., 1977: Tidally induced residual currents in estuaries of constant breadth and depth. J. Mar. Res., 35 , 755786.

  • Ianniello, J. P., 1981: Comments on tidally induced residual currents in estuaries: Dynamics and near bottom flow characteristics. J. Phys. Oceanogr., 11 , 126134.

    • Search Google Scholar
    • Export Citation
  • Jay, D. A., and J. D. Smith, 1990: Residual circulation in shallow estuaries. 2. Weakly stratified and partially mixed, narrow estuaries. J. Geophys. Res., 95 , 733748.

    • Search Google Scholar
    • Export Citation
  • Jay, D. A., and J. M. Musiak, 1996: Internal tidal asymmetry in channel flows: Origins and consequences. Mixing in Estuaries and Coastal Seas, Geophys. Monogr., Vol. 50, Amer. Geophys. Union, 211–249.

    • Search Google Scholar
    • Export Citation
  • Lacy, J. R., M. T. Stacey, J. R. Burau, and S. G. Monismith, 2003: The interaction of lateral baroclinic forcing and turbulence in an estuary. J. Geophys. Res., 108 , 3089. doi:10.1029/2002JC001392.

    • Search Google Scholar
    • Export Citation
  • Li, M., J. Trowbridge, and R. Geyer, 2008: Asymmetric tidal mixing due to the horizontal density gradient. J. Phys. Oceanogr., 38 , 418434.

    • Search Google Scholar
    • Export Citation
  • MacCready, P., 2004: Toward a unified theory of tidally-averaged estuarine salinity structure. Estuaries, 27 , 561570.

  • MacCready, P., 2007: Estuarine adjustment. J. Phys. Oceanogr., 37 , 21332145.

  • McCarthy, R. K., 1993: Residual currents in tidally dominated, well-mixed estuaries. Tellus, 45A , 325340.

  • Nepf, H. M., and W. R. Geyer, 1996: Intratidal variations in stratification and mixing in the Hudson estuary. J. Geophys. Res., 101 , (C5). 1207912086.

    • Search Google Scholar
    • Export Citation
  • Officer, C. B., 1976: Physical Oceanography of Estuaries (and Associated Coastal Waters). John Wiley, 465 pp.

  • Pritchard, D. W., 1952: Salinity distribution and circulation in the Chesapeake Bay estuarine system. J. Mar. Res., 11 , 106123.

  • Pritchard, D. W., 1956: The dynamic structure of a coastal plain estuary. J. Mar. Res., 15 , 3342.

  • Ralston, D. K., W. R. Geyer, and J. A. Lerczak, 2008: Subtidal salinity and velocity in the Hudson River estuary: Observations and modeling. J. Phys. Oceanogr., 38 , 753770.

    • Search Google Scholar
    • Export Citation
  • Scully, M. E., and C. T. Friedrichs, 2007: The importance of tidal and lateral symmetries in stratification to residual circulation in partially mixed estuaries. J. Phys. Oceanogr., 37 , 14961511.

    • Search Google Scholar
    • Export Citation
  • Scully, M. E., W. R. Geyer, and J. A. Lerczak, 2009: The influence of lateral advection on the residual estuarine circulation: A numerical modeling study of the Hudson River estuary. J. Phys. Oceanogr., 39 , 107124.

    • Search Google Scholar
    • Export Citation
  • Simpson, J. H., J. Brown, J. Matthews, and G. Allen, 1990: Tidal straining, density currents, and stirring in the control of estuarine stratification. Estuaries, 13 , 125132.

    • Search Google Scholar
    • Export Citation
  • Simpson, J. H., H. Burchard, N. R. Fisher, and T. P. Rippeth, 2002: The semi-diurnal cycle of dissipation in a ROFI: Model-measurement comparisons. Cont. Shelf Res., 22 , 16151628.

    • Search Google Scholar
    • Export Citation
  • Simpson, J. H., E. Williamsa, L. H. Brasseurb, and J. M. Brubakerb, 2005: The impact of tidal straining on the cycle of turbulence in a partially stratified estuary. Cont. Shelf Res., 25 , 5164.

    • Search Google Scholar
    • Export Citation
  • Stacey, M. T., and D. K. Ralston, 2005: The scaling and structure of the estuarine bottom boundary layer. J. Phys. Oceanogr., 35 , 5571.

    • Search Google Scholar
    • Export Citation
  • Stacey, M. T., J. R. Burau, and S. G. Monismith, 2001: Creation of residual flows in a partially stratified estuary. J. Geophys. Res., 106 , 1701317037.

    • Search Google Scholar
    • Export Citation
  • Stacey, M. T., J. P. Fram, and F. K. Chow, 2008: Role of tidally periodic density stratification in the creation of estuarine subtidal circulation. J. Geophys. Res., 113 , C08016. doi:10.1029/2007JC004581.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 168 103 8
PDF Downloads 149 74 6

Residual Currents Induced by Asymmetric Tidal Mixing in Weakly Stratified Narrow Estuaries

View More View Less
  • 1 Department of Civil and Coastal Engineering, University of Florida, Gainesville, Florida
  • | 2 Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht, Netherlands
Restricted access

Abstract

Residual currents induced by asymmetric tidal mixing were examined for weakly stratified, narrow estuaries using analytical and numerical models. The analytical model is an extension of the work of R. K. McCarthy, with the addition of tidal variations of the vertical eddy viscosity in the longitudinal momentum equation. The longitudinal distribution of residual flows driven by asymmetric tidal mixing is determined by the tidal current amplitude and by asymmetries in tidal mixing between flood and ebb. In a long channel, the magnitude of the residual flow induced by asymmetric tidal mixing is maximum at the estuary mouth and decreases upstream following the longitudinal distribution of tidal current amplitude. Larger asymmetry in tidal mixing between flood and ebb produces stronger residual currents. For typical tidal asymmetry, mixing is stronger during flood than during ebb and results in two-layer residual currents with seaward flow near the surface and landward flow near the bottom. For reverse tidal asymmetry, mixing is weaker during flood than during ebb and the resulting residual flow is landward near the surface and seaward near the bottom. Also, the residual flow induced by tidal asymmetry has the same order of magnitude as the density-driven flow and therefore is important to estuarine dynamics. Numerical experiments with a primitive-equation numerical model [the Regional Ocean Modeling System (ROMS)] generally support the pattern of residual currents driven by tidal asymmetry suggested by the analytical model.

* Current affiliation: Large Lakes Observatory, University of Minnesota, Duluth, Minnesota

Corresponding author address: Peng Cheng, Department of Civil and Coastal Engineering, University of Florida, Gainesville, FL 32611. Email: chengp@d.umn.edu

Abstract

Residual currents induced by asymmetric tidal mixing were examined for weakly stratified, narrow estuaries using analytical and numerical models. The analytical model is an extension of the work of R. K. McCarthy, with the addition of tidal variations of the vertical eddy viscosity in the longitudinal momentum equation. The longitudinal distribution of residual flows driven by asymmetric tidal mixing is determined by the tidal current amplitude and by asymmetries in tidal mixing between flood and ebb. In a long channel, the magnitude of the residual flow induced by asymmetric tidal mixing is maximum at the estuary mouth and decreases upstream following the longitudinal distribution of tidal current amplitude. Larger asymmetry in tidal mixing between flood and ebb produces stronger residual currents. For typical tidal asymmetry, mixing is stronger during flood than during ebb and results in two-layer residual currents with seaward flow near the surface and landward flow near the bottom. For reverse tidal asymmetry, mixing is weaker during flood than during ebb and the resulting residual flow is landward near the surface and seaward near the bottom. Also, the residual flow induced by tidal asymmetry has the same order of magnitude as the density-driven flow and therefore is important to estuarine dynamics. Numerical experiments with a primitive-equation numerical model [the Regional Ocean Modeling System (ROMS)] generally support the pattern of residual currents driven by tidal asymmetry suggested by the analytical model.

* Current affiliation: Large Lakes Observatory, University of Minnesota, Duluth, Minnesota

Corresponding author address: Peng Cheng, Department of Civil and Coastal Engineering, University of Florida, Gainesville, FL 32611. Email: chengp@d.umn.edu

Save