Now showing items 1-15 of 15

  • Bathymetric controls on sediment transport in the Hudson River estuary : lateral asymmetry and frontal trapping 

    Ralston, David K.; Geyer, W. Rockwell; Warner, John C. (American Geophysical Union, 2012-10-17)
    Analyses of field observations and numerical model results have identified that sediment transport in the Hudson River estuary is laterally segregated between channel and shoals, features frontal trapping at multiple ...
  • Climate change, precipitation and impacts on an estuarine refuge from disease 

    Levinton, Jeffrey; Doall, Michael; Ralston, David K.; Starke, Adam; Allam, Bassem (Public Library of Science, 2011-04-28)
    Oysters play important roles in estuarine ecosystems but have suffered recently due to overfishing, pollution, and habitat loss. A tradeoff between growth rate and disease prevalence as a function of salinity makes the ...
  • Effects of estuarine and fluvial processes on sediment transport over deltaic tidal flats 

    Ralston, David K.; Geyer, W. Rockwell; Traykovski, Peter A.; Nidzieko, Nicholas J. (2012-01-25)
    Tidal flats at a river mouth feature estuarine and fluvial processes that distinguish them from tidal flats without river discharge. We combine field observations and a numerical model to investigate hydrodynamics and ...
  • Estuarine exchange flow quantified with isohaline coordinates : contrasting long and short estuaries 

    Chen, Shih-Nan; Geyer, W. Rockwell; Ralston, David K.; Lerczak, James A. (American Meteorological Society, 2012-05)
    Isohaline coordinate analysis is used to compare the exchange flow in two contrasting estuaries, the long (with respect to tidal excursion) Hudson River and the short Merrimack River, using validated numerical models. The ...
  • Estuarine frontogenesis 

    Geyer, W. Rockwell; Ralston, David K. (American Meteorological Society, 2015-02)
    Model studies and observations in the Hudson River estuary indicate that frontogenesis occurs as a result of topographic forcing. Bottom fronts form just downstream of lateral constrictions, where the width of the estuary ...
  • Lateral circulation and sediment transport driven by axial winds in an idealized, partially mixed estuary 

    Chen, Shih-Nan; Sanford, Lawrence P.; Ralston, David K. (American Geophysical Union, 2009-12-03)
    A 3D hydrodynamic model (ROMS) is used to investigate lateral circulation in a partially mixed estuary driven by axial wind events and to explore the associated transport of sediments. The channel is straight with a ...
  • Quantifying vertical mixing in estuaries 

    Geyer, W. Rockwell; Scully, Malcolm E.; Ralston, David K. (Springer, 2008-10-21)
    Estuarine turbulence is notable in that both the dissipation rate and the buoyancy frequency extend to much higher values than in other natural environments. The high dissipation rates lead to a distinct inertial subrange ...
  • Sediment transport and deposition on a river-dominated tidal flat : an idealized model study 

    Chen, Shih-Nan; Geyer, W. Rockwell; Sherwood, Christopher R.; Ralston, David K. (American Geophysical Union, 2010-10-16)
    A 3-D hydrodynamic model is used to investigate how different size classes of river-derived sediment are transported, exported and trapped on an idealized, river-dominated tidal flat. The model is composed of a river channel ...
  • Sediment transport due to extreme events : the Hudson River estuary after tropical storms Irene and Lee 

    Ralston, David K.; Warner, John C.; Geyer, W. Rockwell; Wall, Gary R. (John Wiley & Sons, 2013-10-18)
    Tropical Storms Irene and Lee in 2011 produced intense precipitation and flooding in the U.S. Northeast, including the Hudson River watershed. Sediment input to the Hudson River was approximately 2.7 megaton, about 5 times ...
  • Shear and turbulence production across subtidal channels 

    Ralston, David K.; Stacey, Mark T. (Sears Foundation for Marine Research, 2006-01)
    In intertidal regions with subtidal channels, effects of bathymetry on overlying flow vary greatly with tidal stage. Around low water when mudflats and marsh are exposed, flow is constrained to channels, but when water ...
  • Subtidal salinity and velocity in the Hudson River estuary : observations and modeling 

    Ralston, David K.; Geyer, W. Rockwell; Lerczak, James A. (American Meteorological Society, 2008-04)
    A tidally and cross-sectionally averaged model based on the temporal evolution of the quasi-steady Hansen and Rattray equations is applied to simulate the salinity distribution and vertical exchange flow along the Hudson ...
  • The temporal response of the length of a partially stratified estuary to changes in river flow and tidal amplitude 

    Lerczak, James A.; Geyer, W. Rockwell; Ralston, David K. (American Meteorological Society, 2009-04)
    The temporal response of the length of a partially mixed estuary to changes in freshwater discharge Qf and tidal amplitude UT is studied using a 108-day time series collected along the length of the Hudson River estuary ...
  • Tidal and meteorological forcing of sediment transport in tributary mudflat channels 

    Ralston, David K.; Stacey, Mark T. (2006-01-31)
    Field observations of flow and sediment transport in a tributary channel through intertidal mudflats indicate that suspended sediment was closely linked to advection and dispersion of a tidal salinity front. During calm ...
  • Turbulent mixing in a strongly forced salt wedge estuary 

    Ralston, David K.; Geyer, W. Rockwell; Lerczak, James A.; Scully, Malcolm E. (American Geophysical Union, 2010-12-09)
    Turbulent mixing of salt is examined in a shallow salt wedge estuary with strong fluvial and tidal forcing. A numerical model of the Merrimack River estuary is used to quantify turbulent stress, shear production, and ...
  • Waves in the Red Sea : response to monsoonal and mountain gap winds 

    Ralston, David K.; Jiang, Houshuo; Farrar, J. Thomas (2013-05-30)
    An unstructured grid, phase-averaged wave model forced with winds from a high resolution atmospheric model is used to evaluate wind wave conditions in the Red Sea over an approximately 2-year period. The Red Sea lies in a ...