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Scalar Transport by Propagation of an Internal Solitary Wave over a Slope-Shelf

  • Jin Xu (徐津)
  • Ling-ling Wang (王玲玲)
  • Hong-wu Tang (唐洪武)
  • Zhu Hai (朱海)
  • John James Reginald Williams
Article
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Abstract

Internal solitary waves (ISWs) of depression are common features of the coastal environment and are believed to resuspend sediments in coastal regions where the waves break. In this research, direct numerical simulation is used to study the scalar transport induced by ISWs of depression propagating over a slope–shelf topography. The scalar in this paper is considered to represent concentrations of very fine suspended solids or pollutants. Vortices were observed from the numerical results at the bottom boundary layer on the slope during the ISW shoaling process, resulting in scalar transport. All of the incident ISWs of depression were observed to produce waveform inversion on the shelf. Scalar transport from slope to shelf is the consequence of combined vortices at the bottom boundary layer and overturning of ISWs of depression, and the latter has been commonly ignored in previous study. This study shows that the ISW-induced scalar transport consists of the following four stages: slip transport, wash transport, vortex transport, and secondary transport. A dimensionless time scale for the four stages is calculated, and the beginning time of wash transport and secondary transport is found to be uncorrelated with slope gradients, remaining at 1.26 and 4, respectively.

Key words

Internal solitary waves slope–shelf scalar transport wave inversion dimensionless time scale 

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Copyright information

© China Ship Scientific Research Center 2018

Authors and Affiliations

  • Jin Xu (徐津)
    • 1
    • 2
  • Ling-ling Wang (王玲玲)
    • 1
    • 2
  • Hong-wu Tang (唐洪武)
    • 1
  • Zhu Hai (朱海)
    • 1
    • 2
  • John James Reginald Williams
    • 3
  1. 1.State Key Laboratory of Hydrology-Water Resources and Hydraulic EngineeringNanjingChina
  2. 2.College of Water Conservancy and Hydropower EngineeringHohai UniversityNanjingChina
  3. 3.School of Engineering and Materials ScienceQueen Mary University of LondonLodonUnited Kingdom

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