Vertical Momentum Transfer Due to Internal Waves

A. A. Slepyshev, A. V. Nosova

Marine Hydrophysical Institute of RAS, Sevastopol, Russian Federation

e-mail: slep55@mail.ru

Abstract

Purpose. The work aims to study the vertical momentum transfer by internal waves at the exit of the Strait of Gibraltar into the Mediterranean Sea, accounting for turbulent viscosity and diffusion.

Methods and Results. In contrast to the traditional approach relating vertical momentum transfer to small-scale turbulence, the present study examines the wave transport mechanism. The wave field is described using classical hydrodynamic equations for a stratified incompressible fluid with shear flow, incorporating turbulent viscosity and diffusion. The boundary value problem for the vertical velocity amplitude of internal waves, which conditions the mode structure, is solved numerically. In the linear approximation, the complex nature of the coefficients results in a complex solution, leading to a non-zero vertical wave momentum flux. The impact of horizontal turbulent viscosity and diffusion on this flux is investigated. Three models are compared: the first one – with constant exchange coefficients (basic case), the second – with exchange coefficients depending on phenomenon scale according to the “4/3” law, and the third – with coefficients of horizontal exchange taking into account stratification. It is shown that when the dependence of exchange coefficients on the phenomenon scale according to the “4/3” law is taken into account, the momentum flux is higher in magnitude than that with constant coefficients, but lower than the fluxes taking into account stratification. The same pattern holds for the vertical component of the Stokes drift velocity. The choice of exchange coefficients has virtually no effect on the horizontal component of the Stokes drift velocity.

Conclusions. The dispersion curves of internal waves are independent of the choice of exchange coefficients. However, the wave attenuation decrement is sensitive to this choice: it is higher in magnitude when the exchange coefficients depend on the phenomenon scale according to the “4/3” law compared to the case of constant exchange coefficients, and even higher in absolute value when stratification is taken into account. The same pattern holds true for the vertical wave momentum flux.

Keywords

internal waves, wave momentum flux, Stokes drift, turbulent viscosity, turbulent diffusion

Acknowledgements

This study was conducted under the state assignment of FSBSI FRC MHI (FNNN-2021-0004), titled “Fundamental research of oceanographic processes which determine the state and evolution of marine environment under the impact of natural and anthropogenic factors based on the observation and modeling methods”.

Original russian text

Original Russian Text © A. A. Slepyshev, A. V. Nosova, 2025, published in MORSKOY GIDROFIZICHESKIY ZHURNAL, Vol. 41, Iss. 5, pp. 573-585 (2025)

For citation

Slepyshev, A.A. and Nosova, A.V., 2025. Vertical Momentum Transfer Due to Internal Waves. Physical Oceanography, 32(5), pp. 589-600.

References

  1. Ozmidov, R.V., 1965. [On Turbulent Exchange in a Stably Stratified Ocean]. Izvestiya AN SSSR, Fizika Atmosfery i Okeana, 1(8), pp. 853-860 (in Russian).
  2. Wunsch, C. and Ferrari, R., 2004. Vertical Mixing, Energy, and the General Circulation of the Oceans. Annual Review of Fluid Mechanics, 36(1), pp. 281-314. https://doi.org/10.1146/annurev.fluid.36.050802.122121
  3. Holford, J.M. and Linden, P.F., 1999. Turbulent Mixing in a Stratified Fluid. Dynamics of Atmosphere and Oceans, 30(2-4), pp. 173-198. https://doi.org/10.1016/S0377-0265(99)00025-1
  4. Samodurov, A.S., Lubitsky, A.A. and Panteleev, N.A., 1995. Contribution of Breaking Internal Waves to Structure Formation, Energy Dissipation, and Vertical Diffusion in the Ocean. Physical Oceanography, 6(3), pp. 177-190. https://doi.org/10.1007/BF02197516
  5. Podymov, O.I., Zatsepin, A.G. and Ostrovsky, A.G., 2017. Vertical Turbulent Exchange in the Black Sea Pycnocline and Its Relation to Water Dynamics. Oceanology, 57(4), pp. 492-504. https://doi.org/10.1134/S0001437017040142
  6. Okhotnikov, I.N. and Panteleev, N.A., 1985. Shear Instability of Internal Waves and Vertical Exchange in the Ocean. Morskoy Gidrofizicheskiy Zhurnal, (3), pp. 13-20 (in Russian).
  7. Desabies, Y. and Smith, W.K., 1982. Statistics of Richardson Number and Instability in Oceanic Internal Waves. Journal of Physical Oceanography, 12(11), pp. 1245-1269. https://doi.org/10.1175/1520-0485(1982)012%3C1245:SORNAI%3E2.0.CO;2
  8. Zatsepin, A.G., Golenko, N.N., Korzh, A.O., Kremenetskii, V.V., Paka, V.T., Poyarkov, S.G. and Stunzhas, P.A., 2007. Influence of the Dynamics of Currents on the Hydrophysical Structure of the Waters and the Vertical Exchange in the Active Layer of the Black Sea. Oceanology, 47(3), pp. 301-312. https://doi.org/10.1134/S0001437007030022
  9. Ivanov, A.V., Ostrovsky, L.A., Soustova, I.A. and Tsimring, L.S., 1983. Interaction of Internal Waves and Turbulenсe in the Ocean. Dynamics of Atmosheres and Ocean, 7(4), pp. 221-232. https://doi.org/10.1016/0377-0265(83)90006-4
  10. Soustova, I.A., Troitskaya, Yu.I., Gladskikh, D.S., Mortikov, E.V. and Sergeev, D.A., 2020. A Simple Description of the Turbulent Transport in a Stratified Shear Flow as Applied to the Description of Thermohydrodynamics of Inland Water Bodies. Izvestiya, Atmospheric and Oceanic Physics, 56(6), pp. 603-612. https://doi.org/10.1134/S0001433820060109
  11. Itsweire, E.C., Helland, K.N. and Van Atta, C.W., 1986. The Evolution of Grid-Generated Turbulence in a Stably Stratified Fluid. Journal of Fluid Mechanics, 162(2), pp. 299-338. https://doi.org/10.1017/S0022112086002069
  12. Puig, P., Palanques, A., Guillén, J. and El Khatab, M., 2004. Role of Internal Waves in the Generation of Nepheloid Layers on the Northwestern Alboran Slope: Implications for Continental Margin Shaping. Journal of Geophysical Research: Oceans, 109(C9), C09011. https://doi.org/10.1029/2004JC002394
  13. Kelly, R.E. and Maslowe, S.A., 1970. The Non-Linear Critical Layer in a Slightly Stratified Shear Flow. Studies in Applied Mathematics, 49(4), pp. 301-326.
  14. Robinson, J.L., 1974. The Inviscid Nonlinear Instability of Parallel Shear Flows. Journal of Fluid Mechanics, 63(4), pp. 723-752.
  15. Ostrovsky, L.A. and Zaborskikh, D.V., 1996. Damping of Internal Gravity Waves by Small-Scale Turbulence. Journal of Physical Oceanography, 26(3), pp. 388-397.
  16. Druzhinin, O.A. and Ostrovsky, L.A., 2015. Dynamics of Turbulence under the Effect of Stratification and Internal Waves. Nonlinear Processes in Geophysics, 22(3), pp. 337-348. https://doi.org/10.5194/npg-22-337-2015
  17. Badulin, S.I., Tsymring, L.Sh. and Shrira, V.A., 1983. [Capture and Vertical Focusing of Internal Waves in the Pycnocline by Horizontal Density Field and Current Heterogeneities]. Doklady Akademii Nauk SSSR, 273(2), pp. 459-463 (in Russian).
  18. Bulatov, V.V. and Vladimirov, Yu.V., 2015. Waves in Stratified Media. Moscow: Nauka, 735 p. (in Russian).
  19. Ivanov, V.A., Shul’ga, T.Ya., Bagaev, A.V., Medvedeva, A.V., Plastun, T.V., Verzhevskaia, L.V. and Svishcheva, I.A., 2019. Internal Waves on the Black Sea Shelf near the Heracles Peninsula: Modeling and Observation. Physical Oceanography, 26(4), pp. 288-304. https://doi.org/10.22449/1573-160X-2019-4-288-304
  20. Borisenko, Yu.D., Voronovich, A.G., Leonov, A.I. and Miropolsky, Yu.Z., 1976. On the Theory of Nonstationary Weak Nonlinear Internal Waves in Stratified Fluid. Izvestiya AN SSSR, Fizika Atmosfery i Okeana, 12(3), pp. 293-301 (in Russian).
  21. Grimshaw, R.H.J., 1977. The Modulation of an Internal Gravity-Wave Packet, and the Resonance with the Mean Motion. Studies in Applied Mathematics, 56(3), pp. 241-266. https://doi.org/10.1002/sapm1977563241
  22. LeBlond, P.H. and Mysak, L.A., 1978. Waves in the Ocean. Elsevier Oceanography Series. 20Amsterdam – Oxford – New York: Elsevier Scientific Publishing Company, 602 p.
  23. LeBlond, P.H., 1966. On the Damping of Internal Gravity Waves in a Continuously Stratified Ocean. Journal of Fluid Mechanics, 25(1), pp. 121-142. https://doi.org/10.1017/S0022112066000089
  24. Ostrovsky, L.A. and Soustova, I.A., 1979. The Upper Mixed Layer of the Ocean as an Energy Sink of Internal Waves. Okeanologiya, 19(6), pp. 973-981 (in Russian).
  25. Slepyshev, A.A., 2016. Vertical Momentum Transfer by Internal Waves When Eddy Viscosity and Diffusion Are Taken into Account. Izvestiya, Atmospheric and Oceanic Physics, 52(3), pp. 301-308. https://doi.org/10.1134/S0001433816030117
  26. Slepyshev, A.A., 2022. Vertical Momentum Transfer by Internal Waves in a Shear Flow Taking into Account Turbulent Viscosity and Diffusion. Izvestiya, Atmospheric and Oceanic Physics, 58(5), pp. 433-439. https://doi.org/10.1134/S0001433822050115
  27. Slepyshev, A.A. and Nosova, A.V., 2022. Vertical Transfer of Momentum by Internal Waves in the Western Part of the Mediterranean Sea. Physical Oceanography, 29(4), pp. 334-346. https://doi.org/10.22449/1573-160X-2022-4-334-346
  28. Slepyshev, A.A., 2023. Generation of a Vertical Fine Structure by Internal Waves on the Sea Shelf. Fluid Dynamics, 58(3), pp. 413-426. https://doi.org/10.1134/S0015462822602200
  29. Slepyshev, A.A., 2022. Vertical Momentum Transfer Induced by Internal Inertial-Gravity Waves in Flow with Account of Turbulent Viscosity and Diffusion. Fluid Dynamics, 57(2), pp. 183-192. https://doi.org/10.1134/S0015462822020094
  30. Slepyshev, A.A. and Nosova, A.V., 2020. Generation of Vertical Fine Structure by the Internal Waves with the Regard for Turbulent Viscosity and Diffusion. Physical Oceanography, 27(1), pp. 3-17. https://doi.org/10.22449/1573-160X-2020-1-3-17
  31. Slepyshev, A.A., 2015. Vertical Fluxes Induced by Weak-Nonlinear Internal Waves in a Baroclinic Flow. Physical Oceanography, (1), pp. 59-72. https://doi.org/10.22449/1573-160X-2015-1-59-72
  32. Slepyshev, A.A. and Laktionova, N.V., 2019. Vertical Transport of Momentum by Internal Waves in a Shear Current. Izvestiya, Atmospheric and Oceanic Physics, 55(6), pp. 662-668. https://doi.org/10.1134/S0001433819060148
  33. Slepyshev, A.A. and Schadt, M.A., 2024. Influence of the Nontraditional Approximation on Momentum Transfer by Internal Waves in a Shear Flow. Izvestiya, Atmospheric and Oceanic Physics, 60(5), pp. 515-522. https://doi.org/10.1134/S000143382470052X
  34. Slepyshev, A.A., 2021. Vertical Transfer of Momentum by Inertia-Gravity Internal Waves on a Two-Dimensional Shear Flow. Physical Oceanography, 28(4), pp. 363-375. https://doi.org/10.22449/1573-160X-2021-4-363-375
  35. Ankudinov, N.O. and Slepyshev, A.A., 2021. Vertical Momentum Transfer Induced by Internal Waves in a Two-Dimensional Flow. Fluid Dynamics, 56(3), pp. 343-352. https://doi.org/10.1134/S0015462821030022
  36. Slepyshev, A.A. and Vorotnikov, D.I., 2017. Vertical Heat and Salt Fluxes Induced by Inertia-Gravity Internal Waves on Sea Shelf. Izvestiya, Atmospheric and Oceanic Physics, 53(4), pp. 467-475. https://doi.org/10.1134/S0001433817040119
  37. Bagatinskii, V.A. and Slepyshev, A.A., 2016. Vertical Momentum Transfer by Weakly Nonlinear Inertia-Gravity Internal Waves. Fluid Dynamics, 51(5), pp. 595-605. https://doi.org/10.1134/S0015462816050033
  38. Slepyshev, A.A. and Ankudinov, N.O., 2024. Generation of Vertical Fine Structure by Internal Waves on a Shear Flow. Physical Oceanography, 31(2), pp. 161-177.
  39. Slepyshev, A.A. and Vorotnikov, D.I., 2019. Generation of Vertical Fine Structure by Internal Waves in a Shear Flow. Open Journal of Fluid Dynamics, 9, pp. 140-157. https://doi.org/10.4236/ojfd.201992010
  40. Zhurbas, V. and Oh, I.S., 2003. Lateral Diffusivity and Lagrangian Scales in the Pacific Ocean as Derived from Drifter Data. Journal of Geophysical Research: Oceans, 108(C5), 3141. https://doi.org/10.1029/2002JC001596
  41. Zhurbas, V.M., Zatsepin, A.G., Grigor’eva, Yu.V., Poyarkov, S.G., Eremeev, V.N., Kremenetsky, V.V., Motyzhev, S.V., Stanichny, S.V., Soloviev, D.M. [et al.], 2004. Water Circulation and Characteristics of Currents of Different Scales in the Upper Layer of the Black Sea from Drifter Data. Oceanology, 44(1), pp. 30-43.
  42. Longuet-Higgins, M.S., 1969. On the Transport of Mass by Time-Varying Ocean Currents. Deep Sea Research and Oceanographic Abstracts, 16(5), pp. 431-447. https://doi.org/10.1016/0011-7471(69)90031-X
  43. Watson, G., 1994. Internal Waves in a Stratified Shear Flow: The Strait of Gibraltar. Journal of Physical Oceanography, 24(2), pp. 509-517. https://doi.org/10.1175/1520-0485(1994)024%3C0509:IWIASS%3E2.0.CO;2
  44. Riley, G., 1951. Parameters of Turbulence in the Sea. Journal of Marine Research, 10(3), pp. 267-287.
  45. Permyakov, M.S., Tarkhova, T.I. and Sergienko, A.S., 2005. [Assessment of Horizontal Coefficients of Turbulent Exchange in the Northwestern Pacific Ocean]. Researched in Russia, 8, pp. 860-869 (in Russian).
  46. Nemchenko, V.I., 1964. [Study of Horizontal Turbulent Diffusion in the Atlantic Ocean]. Okeanologiya, 4(5), pp. 805-808 (in Russian).

Download the article (PDF)