Curvature‐ and wind‐driven cross‐channel flows at an unstratified tidal bend
Date
2018-04-19Metadata
Show full item recordCitable URI
https://hdl.handle.net/1912/10461As published
https://doi.org/10.1029/2017JC013722DOI
10.1029/2017JC013722Keyword
Cross‐channel flows; Curvature; Wind; Tidal inlet; Channel bendAbstract
Observations of currents, water levels, winds, and bathymetry collected for a month at an unstratified, narrow (150 m), shallow (8 m), 90° tidal inlet bend are used to evaluate an analytical model for curvature‐driven flow and the effects of local wind on the cross‐channel circulation. Along‐channel flows ranged from −1.0 to 1.4 m/s (positive is inland), and the magnitudes of cross‐channel flows were roughly 0.1–0.2 m/s near the outer bank of the bend. Cross‐channel observations suggest the lateral sea‐surface gradients and along‐channel flows are tidally asymmetric and spatially variable. The depth‐averaged along‐channel dynamics are consistent with a balance between the surface tilt and centrifugal acceleration. The vertical structure and magnitude of cross‐channel flows during weak winds are consistent with a one‐dimensional depth‐varying balance between centrifugal acceleration, bottom stress, and diffusion. Low‐passed (to remove tides) surface and bottom cross‐channel flows are correlated (r2 = 0.5–0.7) with cross‐channel wind velocity, suggesting that winds can enhance or degrade the local‐curvature‐induced, two‐layer flow and can drive three‐layer flow. The observed flow response to the wind is larger than that expected from a one‐dimensional balance, suggesting that two‐dimensional and three‐dimensional processes may be important.
Description
Author Posting. © American Geophysical Union, 2018. 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 123 (2018): 3832-3843, doi:10.1029/2017JC013722.
Collections
Suggested Citation
Journal of Geophysical Research: Oceans 123 (2018): 3832-3843Related items
Showing items related by title, author, creator and subject.
-
Inferring tidal wetland stability from channel sediment fluxes : observations and a conceptual model
Ganju, Neil K.; Nidzieko, Nicholas J.; Kirwan, Matthew L. (John Wiley & Sons, 2013-10-07)Anthropogenic and climatic forces have modified the geomorphology of tidal wetlands over a range of timescales. Changes in land use, sediment supply, river flow, storminess, and sea level alter the layout of tidal channels, ... -
Stage-discharge relationship in tidal channels
Kearney, William S.; Mariotti, Giulio; Deegan, Linda A.; Fagherazzi, Sergio (2016-12)Long-term records of the flow of water through tidal channels are essential to constrain the budgets of sediments and biogeochemical compounds in salt marshes. Statistical models which relate discharge to water level ... -
Hydrodynamics and morphodynamics of shallow tidal channels and intertidal flats
Friedrichs, Carl T. (Woods Hole Oceanographic Institution, 1993-02)In this thesis, mechanisms which control morphodynamics of shallow tidal embayments are investigated analytically. In the process of exploring these mechanisms (specifically asymmetries in bottom stress, τ), basis momentum ...