DOI: 10.1002/2017JC013252
Scopus记录号: 2-s2.0-85044938745
论文题名: Direct Measurements of Mean Reynolds Stress and Ripple Roughness in the Presence of Energetic Forcing by Surface Waves
作者: Scully M.E. ; Trowbridge J.H. ; Sherwood C.R. ; Jones K.R. ; Traykovski P.
刊名: Journal of Geophysical Research: Oceans
ISSN: 21699275
出版年: 2018
卷: 123, 期: 4 起始页码: 2494
结束页码: 2512
语种: 英语
英文关键词: drag
; Reynolds stress
; ripples
Scopus关键词: bed roughness
; boundary layer
; continental shelf
; covariance analysis
; drag
; Reynolds number
; ripple
; seafloor
; sonar
; spatiotemporal analysis
; surface wave
; wave-current interaction
; wavelength
英文摘要: Direct covariance observations of the mean flow Reynolds stress and sonar images of the seafloor collected on a wave-exposed inner continental shelf demonstrate that the drag exerted by the seabed on the overlying flow is consistent with boundary layer models for wave-current interaction, provided that the orientation and anisotropy of the bed roughness are appropriately quantified. Large spatial and temporal variations in drag result from nonequilibrium ripple dynamics, ripple anisotropy, and the orientation of the ripples relative to the current. At a location in coarse sand characterized by large two-dimensional orbital ripples, the observed drag shows a strong dependence on the relative orientation of the mean current to the ripple crests. At a contrasting location in fine sand, where more isotropic sub-orbital ripples are observed, the sensitivity of the current to the orientation of the ripples is reduced. Further, at the coarse site under conditions when the currents are parallel to the ripple crests and the wave orbital diameter is smaller than the wavelength of the relic orbital ripples, the flow becomes hydraulically smooth. This transition is not observed at the fine site, where the observed wave orbital diameter is always greater than the wavelength of the observed sub-orbital ripples. Paradoxically, the dominant along-shelf flows often experience lower drag at the coarse site than at the fine site, despite the larger ripples, highlighting the complex dynamics controlling drag in wave-exposed environments with heterogeneous roughness. © 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/114117
Appears in Collections: 气候减缓与适应
There are no files associated with this item.
作者单位: Applied Ocean Physics and Engineering Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, United States; Coastal and Marine Geology, U.S Geological Survey, Woods Hole, MA, United States
Recommended Citation:
Scully M.E.,Trowbridge J.H.,Sherwood C.R.,et al. Direct Measurements of Mean Reynolds Stress and Ripple Roughness in the Presence of Energetic Forcing by Surface Waves[J]. Journal of Geophysical Research: Oceans,2018-01-01,123(4)