Laboratory Modeling on Transformation of Large-Amplitude Internal Waves by Topographic Obstructions

2011 ◽  
pp. 105-191 ◽  
Author(s):  
N. Gorogedtska ◽  
V. Nikishov ◽  
K. Hutter
Keyword(s):  
Internal Waves ◽  
Large Amplitude ◽  
Laboratory Modeling

scholarly journals Benthic Reef Primary Production in Response to Large Amplitude Internal Waves at the Similan Islands (Andaman Sea, Thailand)

PLoS ONE ◽  
2013 ◽  
Vol 8 (11) ◽  
pp. e81834 ◽  
Author(s):  
Carin Jantzen ◽  
Gertraud M. Schmidt ◽  
Christian Wild ◽  
Cornelia Roder ◽  
Somkiat Khokiattiwong ◽  
...  
Keyword(s):  
Primary Production ◽  
Internal Waves ◽  
Large Amplitude ◽  
Andaman Sea

Finite-amplitude internal wavepacket dispersion and breaking

2001 ◽  
Vol 429 ◽  
pp. 343-380 ◽  
Author(s):  
BRUCE R. SUTHERLAND
Keyword(s):  
Numerical Simulations ◽  
Internal Waves ◽  
Large Amplitude ◽  
Finite Amplitude ◽  
Critical Amplitude ◽  
Fully Nonlinear ◽  
Weakly Nonlinear ◽  
The Stability ◽  
The Waves ◽  
Horizontal Wavelength

The evolution and stability of two-dimensional, large-amplitude, non-hydrostatic internal wavepackets are examined analytically and by numerical simulations. The weakly nonlinear dispersion relation for horizontally periodic, vertically compact internal waves is derived and the results are applied to assess the stability of weakly nonlinear wavepackets to vertical modulations. In terms of Θ, the angle that lines of constant phase make with the vertical, the wavepackets are predicted to be unstable if [mid ]Θ[mid ] < Θc, where Θc = cos−1 (2/3)1/2 ≃ 35.3° is the angle corresponding to internal waves with the fastest vertical group velocity. Fully nonlinear numerical simulations of finite-amplitude wavepackets confirm this prediction: the amplitude of wavepackets with [mid ]Θ[mid ] > Θc decreases over time; the amplitude of wavepackets with [mid ]Θ[mid ] < Θc increases initially, but then decreases as the wavepacket subdivides into a wave train, following the well-known Fermi–Pasta–Ulam recurrence phenomenon.If the initial wavepacket is of sufficiently large amplitude, it becomes unstable in the sense that eventually it convectively overturns. Two new analytic conditions for the stability of quasi-plane large-amplitude internal waves are proposed. These are qualitatively and quantitatively different from the parametric instability of plane periodic internal waves. The ‘breaking condition’ requires not only that the wave is statically unstable but that the convective instability growth rate is greater than the frequency of the waves. The critical amplitude for breaking to occur is found to be ACV = cot Θ (1 + cos2 Θ)/2π, where ACV is the ratio of the maximum vertical displacement of the wave to its horizontal wavelength. A second instability condition proposes that a statically stable wavepacket may evolve so that it becomes convectively unstable due to resonant interactions between the waves and the wave-induced mean flow. This hypothesis is based on the assumption that the resonant long wave–short wave interaction, which Grimshaw (1977) has shown amplifies the waves linearly in time, continues to amplify the waves in the fully nonlinear regime. Using linear theory estimates, the critical amplitude for instability is ASA = sin 2Θ/(8π2)1/2. The results of numerical simulations of horizontally periodic, vertically compact wavepackets show excellent agreement with this latter stability condition. However, for wavepackets with horizontal extent comparable with the horizontal wavelength, the wavepacket is found to be stable at larger amplitudes than predicted if Θ [lsim ] 45°. It is proposed that these results may explain why internal waves generated by turbulence in laboratory experiments are often observed to be excited within a narrow frequency band corresponding to Θ less than approximately 45°.

Long Internal Waves of Large Amplitude

1988 ◽  
pp. 399-406 ◽  
Author(s):  
Motoyasu Miyata
Keyword(s):  
Internal Waves ◽  
Large Amplitude

Direct breaking of large-amplitude internal waves in the Urup Strait

2014 ◽  
Vol 126 ◽  
pp. 109-120 ◽  
Author(s):  
Sachihiko Itoh ◽  
Yuki Tanaka ◽  
Satoshi Osafune ◽  
Ichiro Yasuda ◽  
Masahiro Yagi ◽  
...  
Keyword(s):  
Internal Waves ◽  
Large Amplitude

scholarly journals Mass and momentum transfer by solitary internal waves in a shelf zone

2012 ◽  
Vol 19 (2) ◽  
pp. 265-272 ◽  
Author(s):  
N. Gavrilov ◽  
V. Liapidevskii ◽  
K. Gavrilova
Keyword(s):  
Mathematical Model ◽  
Internal Waves ◽  
Solitary Waves ◽  
Large Amplitude ◽  
Shelf Zone ◽  
Swash Zone ◽  
Second Mode ◽  
Before And After ◽  
The Mathematical Model ◽  
Solitary Internal Waves

Abstract. The evolution of large amplitude internal waves propagating towards the shore and more specifically the run up phase over the "swash" zone is considered. The mathematical model describing the generation, interaction, and decaying of solitary internal waves of the second mode in the interlayer is proposed. The exact solution specifying the shape of solitary waves symmetric with respect to the unperturbed interface is constructed. It is shown that, taking into account the friction on interfaces in the mathematical model, it is possible to describe adequately the change in the phase and amplitude characteristics of two solitary waves moving towards each other before and after their interaction. It is demonstrated that propagation of large amplitude solitary internal waves of depression over a shelf could be simulated in laboratory experiments by internal symmetric solitary waves of the second mode.

scholarly journals Resurrecting dead-water phenomenon

2011 ◽  
Vol 18 (2) ◽  
pp. 193-208 ◽  
Author(s):  
M. J. Mercier ◽  
R. Vasseur ◽  
T. Dauxois
Keyword(s):  
Internal Waves ◽  
Large Amplitude ◽  
Experimental Studies ◽  
Nonlinear Effects ◽  
Stratified Fluid ◽  
Nonlinear Internal Waves ◽  
Induced Drag ◽  
Wave Induced ◽  
Dead Water ◽  
Peculiar Phenomenon

Abstract. We revisit experimental studies performed by Ekman on dead-water (Ekman, 1904) using modern techniques in order to present new insights on this peculiar phenomenon. We extend its description to more general situations such as a three-layer fluid or a linearly stratified fluid in presence of a pycnocline, showing the robustness of dead-water phenomenon. We observe large amplitude nonlinear internal waves which are coupled to the boat dynamics, and we emphasize that the modeling of the wave-induced drag requires more analysis, taking into account nonlinear effects. Dedicated to Fridtjöf Nansen born 150 yr ago (10 October 1861).

Long Internal Waves of Large Amplitude in a Two-Layer Fluid

1986 ◽  
Vol 55 (1) ◽  
pp. 128-144 ◽  
Author(s):  
Mitsuaki Funakoshi ◽  
Masayuki Oikawa
Keyword(s):  
Internal Waves ◽  
Large Amplitude

scholarly journals Large-amplitude internal waves observed in the Kruzenshtern Strait of the Kuril Island Chain and possible water transport and mixing

2010 ◽  
Vol 30 (6) ◽  
pp. 598-607 ◽  
Author(s):  
Tomohiro Nakamura ◽  
Yasuhiro Kawasaki ◽  
Tokihiro Kono ◽  
Toshiyuki Awaji
Keyword(s):  
Water Transport ◽  
Internal Waves ◽  
Large Amplitude ◽  
Kuril Island ◽  
Transport And Mixing

scholarly journals Large-amplitude internal waves benefit corals during thermal stress

2015 ◽  
Vol 282 (1799) ◽  
pp. 20140650 ◽  
Author(s):  
M. Wall ◽  
L. Putchim ◽  
G. M. Schmidt ◽  
C. Jantzen ◽  
S. Khokiattiwong ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Internal Waves ◽  
Coral Bleaching ◽  
Large Amplitude ◽  
Regional Scale ◽  
Total Mortality ◽  
Andaman Sea ◽  
Coral Host ◽  
Conservation Areas ◽  
Sst Anomaly

Tropical scleractinian corals are particularly vulnerable to global warming as elevated sea surface temperatures (SSTs) disrupt the delicate balance between the coral host and their algal endosymbionts, leading to symbiont expulsion, mass bleaching and mortality. While satellite sensing of SST has proved a reliable predictor of coral bleaching at the regional scale, there are large deviations in bleaching severity and mortality on the local scale that are poorly understood. Here, we show that internal waves play a major role in explaining local coral bleaching and mortality patterns in the Andaman Sea. Despite a severe region-wide SST anomaly in May 2010, frequent upslope intrusions of cold sub-pycnocline waters due to breaking large-amplitude internal waves (LAIW) mitigated coral bleaching and mortality in shallow waters. In LAIW-sheltered waters, by contrast, bleaching-susceptible species suffered severe bleaching and total mortality. These findings suggest that LAIW benefit coral reefs during thermal stress and provide local refugia for bleaching-susceptible corals. LAIW are ubiquitous in tropical stratified waters and their swash zones may thus be important conservation areas for the maintenance of coral diversity in a warming climate. Taking LAIW into account can significantly improve coral bleaching predictions and provide a valuable tool for coral reef conservation and management.

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