Impacts of storm surge barriers on drag, mixing, and exchange flow in a partially mixed estuary
Ralston, David K.
MetadataShow full item record
Storm surge barriers are increasingly being considered as risk mitigation measures for coastal population centers. During non-storm periods, permanent barrier infrastructure reduces the flow cross-sectional area and affects tidal exchange. Effects of barrier structures on estuarine tidal and salinity dynamics have not been extensively examined, particularly for partially mixed estuaries. A nested, high-resolution model is used to characterize impacts of a potential storm surge barrier near the mouth of the Hudson River estuary. Maximum tidal velocities through barrier openings are more than double those in the base case. Landward of the barrier, tidal amplitude decreases on average by about 6% due to increased drag. The drag coefficient with the barrier is about 5 times greater than the base case due primarily to form drag from flow separation at barrier structures rather than increased bottom friction. The form drag scales with barrier geometry similar to previous studies of flow around headlands. Tidal water levels are reduced particularly during spring tides, such that marsh inundation frequency is reduced up to 25%. Strong tidal velocities through barrier openings enhance salinity mixing locally, but overall mixing in the estuary decreases due to reduced tidal velocities. Correspondingly, stratification decreases near the barrier and increases landward in the estuary. The salinity intrusion length increases by 5%–15% depending on discharge due to the decreased mixing and increased exchange flow. Exchange flow increases near the barrier due reflux into the lower layer with the increased mixing, which has the potential to increase estuarine residence times.
Author Posting. © American Geophysical Union, 2022. 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 127(4), (2022): e2021JC018246, https://doi.org/10.1029/2021jc018246.
Suggested CitationRalston, D. (2022). Impacts of storm surge barriers on drag, mixing, and exchange flow in a partially mixed estuary. Journal of Geophysical Research: Oceans, 127(4), e2021JC018246.
Showing items related by title, author, creator and subject.
Housego, Rachel M. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2021-06)Nearly 1.5 million people inhabit barrier islands along the U.S. Atlantic and Gulf Coasts and coastal groundwater dynamics influence the availability of freshwater, ecosystem health, pollutant transport, and flooding in ...
Ocean–atmosphere dynamics during Hurricane Ida and Nor’Ida : an application of the coupled ocean–atmosphere–wave–sediment transport (COAWST) modeling system Olabarrieta, Maitane; Warner, John C.; Armstrong, Brandy; Zambon, Joseph B.; He, Ruoying (Elsevier B.V., 2011-12-30)The coupled ocean–atmosphere–wave–sediment transport (COAWST) modeling system was used to investigate atmosphere–ocean–wave interactions in November 2009 during Hurricane Ida and its subsequent evolution to Nor’Ida, which ...
Atmospheric forcing during active convection in the Labrador Sea and its impact on mixed-layer depth Schulze, Lena M.; Pickart, Robert S.; Moore, G. W. K. (John Wiley & Sons, 2016-09-22)Hydrographic data from the Labrador Sea collected in February–March 1997, together with atmospheric reanalysis fields, are used to explore relationships between the air-sea fluxes and the observed mixed-layer depths. The ...