Internal hydraulics and solitary waves in a realistic laboratory model of the Gibraltar Strait

Abstract

We present the first laboratory investigation reproducing realistic internal solitary waves (ISW) in a rotating, tidally forced exchange flow over complex bathymetry, using the Strait of Gibraltar as a dynamically consistent prototype. The experiments reproduce strongly nonlinear ISWs consistent with field observations and resolve their generation, propagation, and hydraulic evolution throughout the tidal cycle. The results reveal fundamentally different generation mechanisms during spring and neap tides. During spring tides, ISWs are generated by the release of an internal hydraulic jump at Camarinal Sill following flow reversal, producing strongly nonlinear bores that may subsequently evolve into solitons. During neap tides, the hydraulic jump remains persistent and weakly nonlinear bores instead arise from nonlinear steepening of the internal tide. Spring-tide internal waves are strongly nonlinear and generate intense Kelvin–Helmholtz instabilities and vigorous mixing, whereas neap-tide internal waves remain weakly nonlinear and are dominated by Holmboe instabilities with substantially weaker mixing. The experiments further demonstrate that maximal exchange in the Strait is maintained during the experiments but does not imply a complete independence from the Mediterranean Sea boundary conditions throughout the Strait. Instead, the spatial extent of the controlled region evolves with the background flow, governing the subsequent evolution of spring-tide internal waves. A simple two-layer hydraulic criterion successfully predicts the bore–soliton transition, identifying local hydraulic criticality as the primary control on wave morphology despite the strongly three-dimensional character of the exchange flow.

An unstructured-grid, nonhydrostatic, GVC ocean model Part I: Model description and application of vertical hybrid coordinates to internal solitary waves
B. J. Pauken, L. Yue, Y. Zhang +2
arXiv4 Nov 2026PreprintarXiv licenceFull textAtmospheric science & meteorology Fluid dynamicsarXiv
Skillful and realistic precipitation forecasting with reinforced diffusion
Ozan Sener, Anand Avati, David Hafner +7
arXiv28 Oct 2026PreprintCC BY 4.0Full textAtmospheric science & meteorologyarXiv
Shallow-to-deep velocity model building via diffusion models-Part II: Realistic scenarios
Shijun Cheng, Randy Harsuko, Tariq Alkhalifah
arXiv22 Sep 2026PreprintCC BY-NC-ND 4.0Full textGeophysics & seismologyarXiv
Towards high-fidelity simulations of coastal submesoscale baroclinic instabilities with MPAS–O (vE3SM3.0.0) – Part 2: Realistic experiments
Dylan R. Schlichting, Katherine M. Smith, Mark R. Petersen +3
Geoscientific Model Development12 Oct 2026Peer-reviewedCC BY 4.0Full textOceanography & cryosphereCrossref
National Soil Carbon Research Programme: Field and Laboratory Methodologies
Jonathan Sanderman, Jeff Baldock, Bruce Hawke +3
CSIRO18 Aug 2026Peer-reviewedLicence not stated62 citedHydrology & soilsOpenAlex

Cite

BibTeX RIS

BibTeX

@article{tassigny2026internal,
  title = {{Internal hydraulics and solitary waves in a realistic laboratory model of the Gibraltar Strait}},
  author = {Axel Tassigny and Lucie Bordois and Xavier J. Carton and Samuel Viboud and Thomas Valran and Maria Eletta Negretti},
  journal = {Deep Sea Research Part I: Oceanographic Research Papers},
  year = {2026},
  month = sep,
  doi = {10.1016/j.dsr.2026.104753},
  url = {https://hal.science/hal-05761694v1},
  note = {CC BY},
}

RIS

TY  - JOUR
TI  - Internal hydraulics and solitary waves in a realistic laboratory model of the Gibraltar Strait
AU  - Axel Tassigny
AU  - Lucie Bordois
AU  - Xavier J. Carton
AU  - Samuel Viboud
AU  - Thomas Valran
AU  - Maria Eletta Negretti
PY  - 2026
DA  - 2026/09/23
JO  - Deep Sea Research Part I: Oceanographic Research Papers
DO  - 10.1016/j.dsr.2026.104753
UR  - https://hal.science/hal-05761694v1
AB  - We present the first laboratory investigation reproducing realistic internal solitary waves (ISW) in a rotating, tidally forced exchange flow over complex bathymetry, using the Strait of Gibraltar as a dynamically consistent prototype. The experiments reproduce strongly nonlinear ISWs consistent with field observations and resolve their generation, propagation, and hydraulic evolution throughout the tidal cycle. The results reveal fundamentally different generation mechanisms during spring and neap tides. During spring tides, ISWs are generated by the release of an internal hydraulic jump at Camarinal Sill following flow reversal, producing strongly nonlinear bores that may subsequently evolve into solitons. During neap tides, the hydraulic jump remains persistent and weakly nonlinear bores instead arise from nonlinear steepening of the internal tide. Spring-tide internal waves are strongly nonlinear and generate intense Kelvin–Helmholtz instabilities and vigorous mixing, whereas neap-tide internal waves remain weakly nonlinear and are dominated by Holmboe instabilities with substantially weaker mixing. The experiments further demonstrate that maximal exchange in the Strait is maintained during the experiments but does not imply a complete independence from the Mediterranean Sea boundary conditions throughout the Strait. Instead, the spatial extent of the controlled region evolves with the background flow, governing the subsequent evolution of spring-tide internal waves. A simple two-layer hydraulic criterion successfully predicts the bore–soliton transition, identifying local hydraulic criticality as the primary control on wave morphology despite the strongly three-dimensional character of the exchange flow.
SN  - 0967-0637
SN  - 1879-0119
ER  -

Abstract

Related

Cite