DOI: 10.1002/2016JC012623
Scopus记录号: 2-s2.0-85042621073
论文题名: Secondary Circulation Asymmetry in a Meandering, Partially Stratified Estuary
作者: Pein J. ; Valle-Levinson A. ; Stanev E.V.
刊名: Journal of Geophysical Research: Oceans
ISSN: 21699275
出版年: 2018
卷: 123, 期: 3 起始页码: 1670
结束页码: 1683
语种: 英语
英文关键词: partially stratified estuary
; secondary circulation
; tidal asymmetry
Scopus关键词: asymmetry
; coastal circulation
; density front
; estuarine dynamics
; estuarine environment
; flood
; internal tide
; meander
; pressure gradient
; saline intrusion
; stratification
; turbulence
; water column
英文摘要: Numerical model experiments are used to study the effects of multiple channel bends on estuarine dynamics and, in particular, on secondary flows. These effects are demonstrated by comparing experiments with two different idealized trumpet-shaped estuaries, one straight and another one with a ∼8 km meandering section in the middle of the estuary. Meanders complicate the flow field by introducing secondary processes. For instance, meanders increase turbulence and associated mixing locally within the water column, as well as outside the meandering portion. Furthermore, meanders transform up to 30% of the along-channel momentum into secondary circulation. Production of turbulence and secondary currents is different at flood and ebb tidal phases. At flood, meanders lead to unstable stratification and increased turbulence. At ebb, the flow develops a helical pattern and adjusts to the channel curvature with minimal decrease in density stability. The secondary circulation asymmetry is caused by an interplay between the across-channel baroclinic pressure gradient force and the centrifugal force. During ebb both forces enhance each other, whereas they oppose during flood. As a consequence of this interaction between baroclinic forcing and curving morphology, ebb flows and horizontal buoyancy fluxes increase relative to flood. The enhanced ebb dominance shifts a density front toward the mouth of the estuary, thus reducing salt intrusion. © 2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114397
Appears in Collections: 气候减缓与适应
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作者单位: Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany; Department of Civil and Coastal Engineering, University of Florida, Gainesville, FL, United States
Recommended Citation:
Pein J.,Valle-Levinson A.,Stanev E.V.. Secondary Circulation Asymmetry in a Meandering, Partially Stratified Estuary[J]. Journal of Geophysical Research: Oceans,2018-01-01,123(3)