scholarly journals Research on the modal intensity fluctuation during the dynamic propagation of internal solitary waves in the shallow water

2022 ◽  
Vol 71 (2) ◽  
pp. 1-13
Author(s):  
Li Qin-Ran ◽  
◽  
Sun Chao ◽  
Xie Lei ◽  
Keyword(s):  
Shallow Water ◽  
Solitary Waves ◽  
Intensity Fluctuation ◽  
Internal Solitary Waves ◽  
Dynamic Propagation

ON THE ADIABATICITY OF ACOUSTIC PROPAGATION THROUGH NONGRADUAL OCEAN STRUCTURES

2001 ◽  
Vol 09 (02) ◽  
pp. 359-365 ◽  
Author(s):  
E. C. SHANG ◽  
Y. Y. WANG ◽  
T. F. GAO
Keyword(s):  
Inverse Problem ◽  
Shallow Water ◽  
Acoustic Field ◽  
Solitary Waves ◽  
Sound Propagation ◽  
Acoustic Propagation ◽  
Forward Problem ◽  
Internal Solitary Waves ◽  
New Criterion

To assess the adiabaticity of sound propagation in the ocean is very important for acoustic field calculating (forward problem) and tomographic retrieving(inverse problem). Most of the criterion in the literature is too restrictive, specially for the nongradual ocean structures. A new criterion of adiabaticity is suggested in this paper. It works for nongradual ocean structures such as front and internal solitary waves in shallow-water.

Acoustic scintillation due to shallow‐water internal solitary waves: Theory and experiment

1997 ◽  
Vol 101 (5) ◽  
pp. 3017-3017
Author(s):  
V. R. Djachenko ◽  
K. V. Konyaev ◽  
D. E. Leikin ◽  
K. D. Sabinin ◽  
Yu. I. Tuzhilkin
Keyword(s):  
Shallow Water ◽  
Solitary Waves ◽  
Internal Solitary Waves ◽  
Theory And Experiment

scholarly journals Internal Solitary Waves Observed on the Continental Shelf in the Northern South China Sea From Acoustic Backscatter Data

2021 ◽  
Vol 8 ◽  
Author(s):  
Yingci Feng ◽  
Qunshu Tang ◽  
Jian Li ◽  
Jie Sun ◽  
Wenhuan Zhan
Keyword(s):  
South China Sea ◽  
Shallow Water ◽  
Solitary Waves ◽  
South China ◽  
Satellite Data ◽  
Northern South China Sea ◽  
Acoustic Backscatter ◽  
Internal Solitary Waves ◽  
Study Region ◽  
China Sea

Internal solitary waves (ISWs) are investigated offshore of Guangdong in the northern South China Sea (SCS) using high-frequency acoustic backscatter data of 100 kHz acquired in July 2020. Simultaneous XBT profiles and satellite images are incorporated to understand their propagation, evolution, and dissipation processes in shallow water at depths less than 50 m. The water column structures revealed by acoustic backscatter data and XBT profiles are consistent with a small difference of less than 3 m. A soliton train with apparent vertical and horizontal scales of ∼7 and 100 m, respectively, is captured three times in 20 h in the repeated acoustic sections, which provides spatiotemporal constraints to the solitons. The characteristics of ISW phase speeds are estimated from acoustic backscatter data and satellite data and using theoretical two-layer Korteweg-de Vries (KdV) and extended KdV (eKdV) models. The acoustically observed phase speed of ISWs is approximately 0.4–0.5 m/s, in agreement with the estimates from both satellite data and model results. The shallow solar-heated water in summer (∼10–20 m) lying on the bottom cold water is responsible for the extensive occurrence of ISWs in the study region. ISWs are dissipated at the transition zone between the heated surface water and the upwelled water, forming a wide ISW dissipation zone in the coastal area, as observed from satellites. The acoustic backscatter method could be an effective way to observe ISWs with high resolution in shallow water and thus a potential compensatory technique for imaging the shallow blind zone of so-called seismic oceanography.

Observations of fine structure changes in shoaling internal solitary waves based on seismic oceanography method

2021 ◽  
Author(s):  
Haibin Song ◽  
Yi Gong ◽  
Yongxian Guan ◽  
Wenhao Fan ◽  
Yunyan Kuang
Keyword(s):  
Fine Structure ◽  
Solitary Wave ◽  
Phase Velocity ◽  
Shallow Water ◽  
Solitary Waves ◽  
Internal Solitary Wave ◽  
Internal Solitary Waves ◽  
Seismic Events ◽  
Velocity Amplitude ◽  
Seismic Oceanography

<p>In the study of shoaling internal solitary waves, the observation and research on the internal fine structure and the effect of the topography are still insufficient. We try to make up for such insufficiency by seismic oceanography method. A first-mode depression internal solitary wave was observed propagating on the continental slope in the northeast South China Sea near Dongsha Atoll. We used common offset gathers (COGs) to obtain a series of images of this internal solitary wave that evolved over time, and studied the changes in internal fine structure by analyzing the seismic events in COG migrated sections. We found that the seismic events were broken during the shoaling, which was caused by the instability induced by internal solitary wave. We picked six events which represent six waveform and analyzed their evolution. It was found that the change in shape of waveform at different depths is different. The waveform in deep water deforms before that in shallow water, and the waveform in shallow water deforms to a greater degree. In addition, we also counted four parameters of phase velocity, amplitude, wavelength, and slopes of front and rear during the shoaling. The results show that the phase velocity and amplitude of waveform in shallow water increases, the wavelength decreases, and the slope of rear gradually becomes larger than that of the front. We have compared the observed changes with previous study made by numerical simulation.</p>

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