Effects of locally generated wind waves on the momentum budget and subtidal exchange in a coastal plain estuary

View/ Open
Date
2019-01-28Author
Pareja‐Roman, L. Fernando
Concept link
Chant, Robert J.
Concept link
Ralston, David K.
Concept link
Metadata
Show full item recordCitable URI
https://hdl.handle.net/1912/24010As published
https://doi.org/10.1029/2018JC014585DOI
10.1029/2018JC014585Keyword
bathymetry; vortex forces; subtidal exchange; wind waves; surface dragAbstract
A numerical model with a vortex force formalism is used to study the role of wind waves in the momentum budget and subtidal exchange of a shallow coastal plain estuary, Delaware Bay. Wave height and age in the bay have a spatial distribution that is controlled by bathymetry and fetch, with implications for the surface drag coefficient in young, underdeveloped seas. Inclusion of waves in the model leads to increases in the surface drag coefficient by up to 30% with respect to parameterizations in which surface drag is only a function of wind speed, in agreement with recent observations of air‐sea fluxes in estuaries. The model was modified to prevent whitecapping wave dissipation from generating breaking forces since that contribution is integrally equivalent to the wind stress. The proposed adjustment is consistent with previous studies of wave‐induced nearshore currents and with additional parameterizations for breaking forces in the model. The mean momentum balance during a simulated wind event was mainly between the pressure gradient force and surface stress, with negligible contributions by vortex, wave breaking (i.e., depth‐induced), and Stokes‐Coriolis forces. Modeled scenarios with realistic Delaware bathymetry suggest that the subtidal bay‐ocean exchange at storm time scales is sensitive to wave‐induced surface drag coefficient, wind direction, and mass transport due to the Stokes drift. Results herein are applicable to shallow coastal systems where the typical wave field is young (i.e., wind seas) and modulated by bathymetry.
Description
Author Posting. © American Geophysical Union, 2019. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research-Oceans 124(2), (2019):1005-1028, doi:10.1029/2018JC014585.
Collections
Suggested Citation
Pareja-Roman, L. F., Chant, R. J., & Ralston, D. K. (2019). Effects of locally generated wind waves on the momentum budget and subtidal exchange in a coastal plain estuary. Journal of Geophysical Research-Oceans, 124(2), 1005-1028.Related items
Showing items related by title, author, creator and subject.
-
Markov chain analysis of succession in a rocky subtidal community
Hill, M. Forrest; Witman, Jon D.; Caswell, Hal (University of Chicago Press, 2004-07-01)We present a Markov chain model of succession in a rocky subtidal community based on a long-term (1986–1994) study of subtidal invertebrates (14 species) at Ammen Rock Pinnacle in the Gulf of Maine. The model describes ... -
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 ... -
Fortnightly tides and subtidal motions in a choked inlet
MacMahan, Jamie; van de Kreeke, Jacobus; Reniers, Ad; Elgar, Steve; Raubenheimer, Britt; Thornton, Ed B.; Weltmer, Micah; Rynne, Patrick; Brown, Jenna (Elsevier, 2014-04-12)Amplitudes of semi-diurnal tidal fluctuations measured at an ocean inlet system decay nearly linearly by 87% between the ocean edge of the offshore ebb-tidal delta and the backbay. A monochromatic, dynamical model for a ...