Sponsor
Funding was provided by the U.S. Army Corps of Engineers (Award W1927N‐14‐2‐0015) and the National Science Foundation, Awards 1854946 and 1455350.
Published In
Journal of Geophysical Research: Oceans
Document Type
Article
Publication Date
2020
Subjects
Storm surges -- Mathematical models, Storm surges -- Effect of channel deepening on, Tides
Abstract
We develop idealized analytical and numerical models to study how storm surge amplitudes vary within frictional, weakly convergent, nonreflective estuaries. Friction is treated using Chebyshev polynomials. Storm surge is represented as the sum of two sinusoidal components, and a third constituent represents the semidiurnal tide (D2). An empirical fit of storm surge shows that two sinusoidal components adequately represent storm surge above a baseline value (R2 = 0.97). We find that the spatial transformation of surge amplitudes depends on the depth of the estuary, and characteristics of the surge wave including time scale, amplitude, asymmetry, and surge‐tide relative phase. Analytical model results indicate that surge amplitude decays more slowly (larger e‐folding) in a deeper channel for all surge time scales (12–72 hr). Deepening of an estuary results in larger surge amplitudes. Sensitivity studies show that surges with larger primary amplitudes (or shorter time scales) damp faster than those with smaller amplitudes (or larger time scales). Moreover, results imply that there is a location with maximum sensitivity to altered depth, offshore surge amplitude, and time scale and that the location of observed maximum change in surge amplitude along an estuary of simple form moves upstream when depth is increased. Further, the relative phase of surge to tide and surge asymmetry can change the spatial location of maximum change in surge. The largest change due to increased depth occurs for a large surge with a short time scale. The results suggest that both sea level rise and channel deepening may also alter surge amplitudes.
Rights
©2020. American Geophysical Union. All Rights Reserved
Locate the Document
DOI
10.1029/2019JC015286
Persistent Identifier
https://archives.pdx.edu/ds/psu/34926
Citation Details
Familkhalili, R., Talke, S. A., & Jay, D. A. (2020). Tide‐storm surge interactions in highly altered estuaries: How channel deepening increases surge vulnerability. Journal of Geophysical Research: Oceans, 125, e2019JC015286.
Description
The data used in this study can be obtained from NOAA's Center for Operational Oceanographic Products and Services website (https:// tidesandcurrents.noaa.gov).