Studying breaking waves with ambient noise oceanography

2016 ◽  
Vol 140 (4) ◽  
pp. 2977-2977
Author(s):  
Grant B. Deane
Keyword(s):  
Ambient Noise ◽  
Breaking Waves

Shallow‐water ambient noise caused by breaking waves in the surf zone.

1996 ◽  
Vol 99 (4) ◽  
pp. 2453-2457
Author(s):  
Oscar B. Wilson ◽  
Marc S. Stewart ◽  
James H. Wilson ◽  
Robert H. Bourke
Keyword(s):  
Shallow Water ◽  
Ambient Noise ◽  
Surf Zone ◽  
Breaking Waves

Bulk drag coefficient of a subaquatic vegetation subjected to irregular waves: Influence of Reynolds and Keulegan-Carpenter numbers

2020 ◽  
pp. 34-42
Author(s):  
Thibault Chastel ◽  
Kevin Botten ◽  
Nathalie Durand ◽  
Nicole Goutal
Keyword(s):  
Drag Coefficient ◽  
Wave Height ◽  
Wave Attenuation ◽  
Empirical Relationship ◽  
Breaking Waves ◽  
Irregular Waves ◽  
Geometrical Parameters ◽  
Flume Experiments ◽  
Seagrass Meadows ◽  
Artificial Vegetation

Seagrass meadows are essential for protection of coastal erosion by damping wave and stabilizing the seabed. Seagrass are considered as a source of water resistance which modifies strongly the wave dynamics. As a part of EDF R & D seagrass restoration project in the Berre lagoon, we quantify the wave attenuation due to artificial vegetation distributed in a flume. Experiments have been conducted at Saint-Venant Hydraulics Laboratory wave flume (Chatou, France). We measure the wave damping with 13 resistive waves gauges along a distance L = 22.5 m for the “low” density and L = 12.15 m for the “high” density of vegetation mimics. A JONSWAP spectrum is used for the generation of irregular waves with significant wave height Hs ranging from 0.10 to 0.23 m and peak period Tp ranging from 1 to 3 s. Artificial vegetation is a model of Posidonia oceanica seagrass species represented by slightly flexible polypropylene shoots with 8 artificial leaves of 0.28 and 0.16 m height. Different hydrodynamics conditions (Hs, Tp, water depth hw) and geometrical parameters (submergence ratio α, shoot density N) have been tested to see their influence on wave attenuation. For a high submergence ratio (typically 0.7), the wave attenuation can reach 67% of the incident wave height whereas for a low submergence ratio (< 0.2) the wave attenuation is negligible. From each experiment, a bulk drag coefficient has been extracted following the energy dissipation model for irregular non-breaking waves developed by Mendez and Losada (2004). This model, based on the assumption that the energy loss over the species meadow is essentially due to the drag force, takes into account both wave and vegetation parameter. Finally, we found an empirical relationship for Cd depending on 2 dimensionless parameters: the Reynolds and Keulegan-Carpenter numbers. These relationships are compared with other similar studies.

Analysis and Modeling of Ambient Noise in Shallow Water of Arabian Sea

2012 ◽  
Vol 2 (6) ◽  
pp. 271-272
Author(s):  
Sudhir Pal Singh Rawat ◽  
◽  
Dr. Arnab Das ◽  
Dr. H.G.Virani Dr. H.G.Virani ◽  
Dr. Y.K.Somayajulu Dr. Y.K.Somayajulu
Keyword(s):  
Shallow Water ◽  
Arabian Sea ◽  
Ambient Noise

Particularities of tinnitus in children and adolescents

ORL ro ◽  
2016 ◽  
Vol 4 (1) ◽  
pp. 40-42
Author(s):  
Alexandra Boloș ◽  
Sebastian Cozma ◽  
Andreea Silvana Szalontay
Keyword(s):  
Quality Of Life ◽  
Young Adults ◽  
Children And Adolescents ◽  
Psychological Factors ◽  
Ambient Noise ◽  
Psychological Consequences ◽  
Therapeutic Approaches

Tinnitus is a common otologic symptom and probably the most troublesome. Tinnitus causes a number of physical and psychological consequences, that interfere with the quality of life of the patient. Many authors believe that the presence of tinnitus in children is a matter of lesser importance than in adults because it is met less frequently and would be a fleeting symptom, inoffensive for them (Graham, 1981). In addition, the prevalence of tinnitus during adolescence and even in young adults is increasing, possibly as a consequence of the increased ambient noise (Bulbul SF, Shargorodsky J). Various therapeutic approaches have generated different results, which led us to consider the role of psychological factors, hence the need to underline the particularities of this symptom in childhood.  

PHYSICAL INTERPRETATION OF WAVE BREAKING CRITERIA

2017 ◽  
Author(s):  
Sergey Kuznetsov ◽  
Sergey Kuznetsov ◽  
Yana Saprykina ◽  
Yana Saprykina ◽  
Boris Divinskiy ◽  
...  
Keyword(s):  
Nonlinear Wave ◽  
Wave Breaking ◽  
Second Harmonic ◽  
Vertical Axis ◽  
Breaking Waves ◽  
Wave Transformation ◽  
Spectral Structure ◽  
Similarity Parameter ◽  
Nonlinear Harmonics ◽  
The Waves

On the base of experimental data it was revealed that type of wave breaking depends on wave asymmetry against the vertical axis at wave breaking point. The asymmetry of waves is defined by spectral structure of waves: by the ratio between amplitudes of first and second nonlinear harmonics and by phase shift between them. The relative position of nonlinear harmonics is defined by a stage of nonlinear wave transformation and the direction of energy transfer between the first and second harmonics. The value of amplitude of the second nonlinear harmonic in comparing with first harmonic is significantly more in waves, breaking by spilling type, than in waves breaking by plunging type. The waves, breaking by plunging type, have the crest of second harmonic shifted forward to one of the first harmonic, so the waves have "saw-tooth" shape asymmetrical to vertical axis. In the waves, breaking by spilling type, the crests of harmonic coincides and these waves are symmetric against the vertical axis. It was found that limit height of breaking waves in empirical criteria depends on type of wave breaking, spectral peak period and a relation between wave energy of main and second nonlinear wave harmonics. It also depends on surf similarity parameter defining conditions of nonlinear wave transformations above inclined bottom.

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