DOI: 10.1002/grl.50322
论文题名: Observations of enhanced nonlinear instability in the surface reflection of internal tides
作者: Xie X. ; Shang X. ; Van Haren H. ; Chen G.
刊名: Geophysical Research Letters
ISSN: 0094-9141
EISSN: 1944-8872
出版年: 2013
卷: 40, 期: 8 起始页码: 1580
结束页码: 1586
语种: 英语
英文关键词: internal tides
; mean flow
; nonlinear instability
; parametric subharmonic instability
; reflection
Scopus关键词: Internal tides
; Mean flow
; Nonlinear instability
; Nonlinear interactions
; Propagation direction
; Spectral decomposition
; Subharmonic instability
; Vertically-standing waves
; Reflection
; Stability
; Tides
; harmonic analysis
; instability
; internal tide
; nonlinearity
; parameterization
; spectral analysis
; standing wave
; timescale
; wave velocity
; Pacific Ocean
; South China Sea
英文摘要: Enhanced vertically standing waves formed by the superposition of two upward and downward going near-diurnal (D1) waves are observed during one semidiurnal (D2) spring tide in an approximately 75 day long velocity record from the northeastern South China Sea. Bicoherence estimates suggest that the enhanced D1 waves are likely due to nonlinear parametric subharmonic instability of D2 internal tides. The timescale for energy growth by an order of magnitude is about 2.5 days for these waves. In addition to subharmonics, higher harmonics D4 (=D 2 + D2) and a mean flow are generated by a different nonlinear interaction during the same D2 spring tide. The separation of coherent from incoherent internal tidal signals and a rotary spectral decomposition in the vertical direction reveal that D2 waves with opposite vertical propagation directions in the region of internal tide reflection from the surface may be responsible for the pronounced nonlinear instability. Key Points Internal tides reflect from the sea-surface in the South China Sea Internal tide subharmonic instability is rapidly enhanced in the reflection area A mean flow is generated by nonlinear interaction between internal tides. ©2013. American Geophysical Union. All Rights Reserved. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84877944612&doi=10.1002%2fgrl.50322&partnerID=40&md5=9594efd24166a68dec739b7155ccaaa3
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/6405
Appears in Collections: 气候减缓与适应
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作者单位: State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
Recommended Citation:
Xie X.,Shang X.,Van Haren H.,et al. Observations of enhanced nonlinear instability in the surface reflection of internal tides[J]. Geophysical Research Letters,2013-01-01,40(8).