DOI: 10.1002/2017JC013388
Scopus记录号: 2-s2.0-85044758950
论文题名: Generation and Propagation of Nonlinear Internal Waves in Sheared Currents Over the Washington Continental Shelf
作者: Hamann M.M. ; Alford M.H. ; Mickett J.B.
刊名: Journal of Geophysical Research: Oceans
ISSN: 21699275
出版年: 2018
卷: 123, 期: 4 起始页码: 2381
结束页码: 2400
语种: 英语
英文关键词: generation
; nonlinear internal wave
; propagation
; shear
; turbulence
Scopus关键词: continental shelf
; energy dissipation
; energy flux
; internal tide
; internal wave
; mooring system
; shear
; shoaling wave
; turbulence
; wave generation
; wave propagation
; United States
; Washington [United States]
英文摘要: The generation, propagation, and dissipation of nonlinear internal waves (NLIW) in sheared background currents is examined using 7 days of shipboard microstructure surveys and two moorings on the continental shelf offshore of Washington state. Surveys near the hypothesized generation region show semi-diurnal (D2) energy flux is onshore and that the ratio of energy flux to group speed times energy ((F/cgE)) increases sharply at the shelf break, suggesting that the incident D2 internal tide is partially reflected and partially transmitted. NLIW appear at an inshore mooring at the leading edge of the onshore phase of the baroclinic tide, consistent with nonlinear transformation of the shoaling internal tide as their generation mechanism. Of the D2 energy flux observed at the eastern extent of the generation region (133 ± 18 Wm−1), approximately 30% goes into the NLIW observed inshore (36 ± 11 Wm−1). Inshore of the moorings, 7 waves are tracked into shallow (30-40 m) water, where a vertically sheared, southward current becomes strong. As train-like waves propagate onshore, wave amplitudes of 25-30 m and energies of 5 MJ decrease to 12 m and 10 kJ, respectively. The observed direction of propagation rotates from 30° N of E to ˜30° S of E in the strongly sheared region. Linear ray tracing using the Taylor-Goldstein equation to incorporate parallel shear effects accounts for only a small portion of the observed rotation, suggesting that three-dimensionality of the wave crests and the background currents is important here. © 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/114134
Appears in Collections: 气候减缓与适应
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作者单位: Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, United States; Applied Physics Laboratory, University of Washington, Seattle, WA, United States
Recommended Citation:
Hamann M.M.,Alford M.H.,Mickett J.B.. Generation and Propagation of Nonlinear Internal Waves in Sheared Currents Over the Washington Continental Shelf[J]. Journal of Geophysical Research: Oceans,2018-01-01,123(4)