Frontogenesis, Mixing, and Stratification in Estuarine Channels with Curvature
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phoc-JPO-D-21-0298.1.pdf
Size
3.28 MB
Format
Adobe PDF
Checksum (MD5)
ce0218afb5006e8803ccaf749939f7d8
Author(s)
Bo, Tong
Ralston, David
Date Issued
June 9, 2022
Journal
Journal of Physical Oceanography
Publisher
American Meteorological Society
Citation
Bo, T., and D. K. Ralston, 2022: Frontogenesis, Mixing, and Stratification in Estuarine Channels with Curvature. J. Phys. Oceanogr., 52, 1333–1350.
Version
Final published version
Abstract
Idealized numerical simulations were conducted to investigate the influence of channel curvature on estuarine stratification and mixing. Stratification is decreased and tidal energy dissipation is increased in sinuous estuaries compared to straight channel estuaries. We applied a vertical salinity variance budget to quantify the influence of straining and mixing on stratification. Secondary circulation due to the channel curvature is found to affect stratification in sinuous channels through both lateral straining and enhanced vertical mixing. Alternating negative and positive lateral straining occur in meanders upstream and downstream of the bend apex, respectively, corresponding to the normal and reversed secondary circulation with curvature. The vertical mixing is locally enhanced in curved channels with the maximum mixing located upstream of the bend apex. Bend-scale bottom salinity fronts are generated near the inner bank upstream of the bend apex as a result of interaction between the secondary flow and stratification. Shear mixing at bottom fronts, instead of overturning mixing by the secondary circulation, provides the dominant mechanism for destruction of stratification. Channel curvature can also lead to increased drag, and using a Simpson number with this increased drag coefficient can relate the decrease in stratification with curvature to the broader estuarine parameter space.
Subjects
Estuaries
Mixing
Secondary circulation
Fronts
Tides
Numerical analysis/modeling
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1175/JPO-D-21-0298.1
