The influence of lateral advection on the residual estuarine circulation : a numerical modeling study of the Hudson River Estuary
Scully, Malcolm E.
Geyer, W. Rockwell
Lerczak, James A.
MetadataShow full item record
In most estuarine systems it is assumed that the dominant along-channel momentum balance is between the integrated pressure gradient and bed stress. Scaling the amplitude of the estuarine circulation based on this balance has been shown to have predictive skill. However, a number of authors recently highlighted important nonlinear processes that contribute to the subtidal dynamics at leading order. In this study, a previously validated numerical model of the Hudson River estuary is used to examine the forces driving the residual estuarine circulation and to test the predictive skill of two linear scaling relationships. Results demonstrate that the nonlinear advective acceleration terms contribute to the subtidal along-channel momentum balance at leading order. The contribution of these nonlinear terms is driven largely by secondary lateral flows. Under a range of forcing conditions in the model runs, the advective acceleration terms nearly always act in concert with the baroclinic pressure gradient, reinforcing the residual circulation. Despite the strong contribution of the nonlinear advective terms to the subtidal dynamical balance, a linear scaling accurately predicts the strength of the observed residual circulation in the model. However, this result is largely fortuitous, as this scaling does not account for two processes that are fundamental to the estuarine circulation. The skill of this scaling results because of the compensatory relationship between the contribution of the advective acceleration terms and the suppression of turbulence due to density stratification. Both of these processes, neither of which is accounted for in the linear scaling, increase the residual estuarine circulation but have an opposite dependence on tidal amplitude and, consequently, strength of stratification.
Author Posting. © American Meteorological Society, 2009. 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 Physical Oceanography 39 (2009): 107-124, doi:10.1175/2008JPO3952.1.
Suggested CitationJournal of Physical Oceanography 39 (2009): 107-124
Showing items related by title, author, creator and subject.
Comparison of physical to numerical mixing with different tracer advection schemes in estuarine environments Kalra, Tarandeep S.; Li, Xiangyu; Warner, John C.; Geyer, W. Rockwell; Wu, Hui (MDPI, 2019-09-26)The numerical simulation of estuarine dynamics requires accurate prediction for the transport of tracers, such as temperature and salinity. During the simulation of these processes, all the numerical models introduce two ...
Kranenburg, Wouter M.; Geyer, W. Rockwell; Garcia, Adrian Mikhail P.; Ralston, David K. (American Meteorological Society, 2019-06-13)Although the hydrodynamics of river meanders are well studied, the influence of curvature on flow in estuaries, with alternating tidal flow and varying water levels and salinity gradients, is less well understood. This ...
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 ...