quadrupolar – Douglas Dommermuth, ScD.

Breaking waves generate meandering currents and winds in the oceanic and atmospheric boundary layers (Dommermuth et al., 2014). Meandering flows are revisited here for five types of breaking waves. Streaming flows are mean flows that include Eulerian and Lagrangian contributions. Meandering flows include both difference (streaming) and sum frequency interactions. Meandering flows, like streaming flows, have Eulerian and Lagrangian contributions. Normal to the free surface, the meandering flows exponentially attenuate away from the free surface with an oscillatory behavior. The magnitudes of the meandering flows agree with Langmuir’s original observations (Langmuir, 1938). The good agreement suggests that the formation of Langmuir circulations is due to meandering flows.… Read more

January 4, 2021

Magnetic Induction due to the Effects of Breaking Ocean Waves

https://www.researchgate.net/publication/344482876

Breaking waves generate meandering currents and winds in the oceanic and atmospheric boundary layers. The length scales and frequencies of the meandering currents and winds are respectively longer and higher than those of the underlying ocean waves. The difference in spatial and temporal scales makes it possible to indirectly measure the meandering current in the oceanic boundary layer using the principles of magnetic induction that would otherwise be difficult using more direct methods. Such measurements are desirable to quantify mixing in the oceanic and atmospheric boundary layers due to meandering flows.

January 4, 2021

The Generation of Electric Fields by Meandering Flows

https://www.researchgate.net/publication/344787449

Meandering flows are wave driven much like streaming flows. The interaction of the wavy portion of the flow with the vortical portion of the flow gives rise to meandering flows. Meandering flows, like streaming flows, are not turbulent. The nonlinear wave interactions give sum and difference frequencies in meandering flows. The difference frequencies have long been associated with streaming flows in the ocean (Longuet-Higgins, 1953). Meandering flows occur in the atmosphere as well as the ocean. Streaming flows are a subset of meandering flows. Meandering flows are expected to vary over long distances due to nonlinear wave interactions, variations in currents and winds, etc. In the upper ocean, (Dommermuth, 2020d) shows that slow variations of the meandering wind-drift interacting with the earth’s magnetic field induces a magnetic disturbance in the upper ocean and lower atmosphere. Dommermuth (2018b,c,d,e) show how the wind drift affects wave breaking. Here, the effects of variations in the meandering wind drift and meandering wind on the surface charge density are considered. Blanchard (1963); Gathman (1986) show that the surface charge density is due to the electrification of the atmosphere by (1) bubbles bursting on the ocean surface due to the effects of wave breaking and (2) sea spray torn off the crests of waves by wind shear. The variations in surface charge density are expected due to variations in wave breaking and wind shear occurring over long spatial scales due to meandering flows. This paper along with Dommermuth (2020d) provide experimentalists with bases for measuring effects of meandering flows on the magnetic and electric fields in the ocean and atmosphere. Experiments can be performed to confirm the existence of meandering flows and to quantify the mixing of the upper ocean and lower atmosphere. During fair weather the electric field that is generated by the effect of meandering flows on the surface charge density is about 10% of the potential gradient at altitudes 3km above the ocean surface. The effects of the electric disturbance attenuate slowly with altitude at a rate that is very similar to the potential gradient. The frequencies of oscillations are about 0.2-1Hz due to nonlinear sum-frequency wave interactions. During a storm the electric field that is generated by the meandering flows would become increasingly violent with significant energy being radiated within specific frequency bands in an organized manner.

January 2, 2021January 22, 2021

Spilling Breaking Ocean Waves and Inverse Energy Cascades

https://www.researchgate.net/publication/348136300

The Ocean’s Heartbeat (OH) is an inverse energy cascade that occurs through interactions between surface gravity waves and organized vortical structures in the atmosphere and the ocean. The vortical wake of spilling breaking waves can generate the inverse energy cascade even in the absence of wind and current shear. Standing waves are generated as the vortical portions of the flow modulate the generation and evolution of surface gravity waves and vice versa. Resonances occur between the standing waves and coherent structures in the ocean. Monopolar, dipolar, tripolar, and quadrupolar vortical structures (OH structures) are shed out the back of spilling breaking waves. Intense OH structures generate knots in the free-surface elevation in the wake of spilling breaking waves. OH structures surf the crests of spilling breaking waves slightly behind the whitecaps. The results of numerical simulations give credence to two conjectures: 1) OH standing waves can generate microseisms even when opposing wave groups are not present and 2) The OH inverse energy cascade is present in satellite altimetry of sea surface height measurements.

December 6, 2020July 15, 2024

Research Papers and Reports

Langmuir Circulations and Meandering Flows

Dommermuth, D. G., Rhymes, L. E., and Rottman, J. W., “Direct Simulations of Breaking Ocean Waves with Data Assimilation,” OCEANS, 2013, San Diego, California, USA, 2013. https://www.researchgate.net/publication/269573554
Dommermuth, D. G., Lewis, C. D., Tran, V. H., and Valenciano, M. A., “Direct Simulations of Wind- Driven Breaking Ocean Waves with Data Assimilation,” Proceedings of the 30th Symposium on Naval Hydrodynamics, Hobart, Tasmania, Australia, 2014. https://www.researchgate.net/publication/266396605
Dommermuth, D. G., “Meandering Flows in the Oceanic and Atmospheric Boundary Layers due to Breaking Ocean Waves,” ResearchGate preprint, Oct 2020. https://www.researchgate.net/publication/344482927

Windrows

Dommermuth, D. G., “Further Observations on how Wave Breaking Affects the Formation of Windrows,” ResearchGate preprint, Oct 2020. https://www.researchgate.net/publication/344482865
Dommermuth, D. G., “Windrows,” ResearchGate preprint, Oct 2020. https://www.researchgate.net/publication/344943225

The Ocean’s Heartbeat

Dommermuth, D.G., “The Ocean’s Heartbeat,” ResearchGate preprint, Dec 2020. https://www.researchgate.net/publication/347514163
Dommermuth, D.G., “Spilling Breaking Ocean Waves and Inverse Energy Cascades,” ResearchGate preprint, Jan 2021. https://www.researchgate.net/publication/348136300
Dommermuth, D.G., “Frequency Downshifting and Inverse Energy Cascades,” ResearchGate preprint, Jan 2021. https://www.researchgate.net/publication/348419601
Dommermuth, D.G., “Knots and Streaks – Where to Find Them,” ResearchGate preprint, Jan 2021. https://www.researchgate.net/publication/348578523
Dommermuth, D.G., “Whitecaps, Inverse Energy Cascades, and Energy Budgets,” ResearchGate preprint, April 2021. https://www.researchgate.net/publication/350874498
Dommermuth, D.G., “An Annotated Bibliography of the Ocean’s Heartbeat,” ResearchGate preprint, April 2021. https://www.researchgate.net/publication/351234250
Dommermuth, D.G., “Modeling the Ocean’s Heartbeat,” ResearchGate preprint, April 2021. https://www.researchgate.net/publication/352410045
Dommermuth, D.G., “The Ocean’s Heartbeat,” 27th WISE Meeting, Bergen, Norway, September 5-9, 2021. https://www.researchgate.net/publication/354152802
Dommermuth, D.G., “The Ocean’s Heartbeat,” Poster presentation, 27th WISE Meeting, Bergen, Norway, September 5-9, 2021. https://www.researchgate.net/publication/354151421
Dommermuth, D.G., “The Ocean’s Heartbeat: An Inverse Energy Cascade that Mixes the Lower Atmosphere and Upper Ocean,” PowerPoint presentation, Air-Sea Interactions and Implications for Offshore Wind Energy, virtual event, February 10-11, 2022. https://www.researchgate.net/publication/358510653
Dommermuth, D.G., “An Overview of the Ocean’s Heartbeat,” WISE 2022 Meeting, Brest, France, May 29-June 2, 2022. https://www.researchgate.net/publication/358228366
Dommermuth, D.G., “An Overview of the Ocean’s Heartbeat,” PowerPoint presentation, WISE 2022 Meeting, Brest, France, May 29-June 2, 2022. https://www.researchgate.net/publication/360978580
Dommermuth, D.G., “The Ocean’s Heartbeat: An Inverse Energy Cascade that Mixes the Lower Atmosphere and Upper Ocean,” 34th Symposium on Naval Hydrodynamics, Washington, D.C., USA, June 26 – July 1, 2022. https://www.researchgate.net/publication/361556689
Dommermuth, D.G., “Frameworks for Studying the Ocean’s Heartbeat,” 35th Symposium on Naval Hydrodynamics, Nantes, France, July 8-12, 2024. https://www.researchgate.net/publication/381128147
Dommermuth, D.G., “Frameworks for Studying the Ocean’s Heartbeat,” PowerPoint presentation, 35th Symposium on Naval Hydrodynamics, Nantes, France, July 8-12, 2024. https://www.researchgate.net/publication/382268957

Electric and Magnetic Fields of Meandering Flows

Dommermuth, D. G., “Magnetic Induction due to the Effects of Breaking Ocean Waves,” ResearchGate preprint, Oct 2020.
https://www.researchgate.net/publication/344482876
Dommermuth, D. G., “The Generation of Electric Fields by Meandering Flows,” ResearchGate preprint, Oct 2020. https://www.researchgate.net/publication/344787449 (Please see more recent technical reports on the electric field that is induced by the transport of space charge density by the meandering wind.)
Dommermuth, D. G., “The Electric and Magnetic Fields due to the Transport of Space Charge Density by the Meandering Wind over the Ocean Surface,” ResearchGate preprint, Sep 2021. https://www.researchgate.net/publication/354665883 (Please see more recent technical reports on the electric field that is induced by the transport of space charge density by the meandering wind.)
Dommermuth, D.G., “The Electric and Magnetic Fields due to the Transport of Space Charge Density by the Meandering Wind over the Ocean Surface: New Evidence of an Inverse Energy Cascade in the Lower Atmosphere,” ResearchGate preprint, Sep 2021. https://www.researchgate.net/publication/354935485
Dommermuth, D.G., “The Electric and Magnetic Fields due to Magnetic Induction by Meandering Flows in the Oceanic and Atmospheric Boundary Layers: New Evidence of an Inverse Energy Cascade in the Upper Ocean,” ResearchGate preprint, Oct 2021. https://www.researchgate.net/publication/355215804
Dommermuth, D.G., “The Magnetic Fields due to Magnetic Induction by Meandering Drift Currents,” ResearchGate preprint, Oct 2021. https://www.researchgate.net/publication/355651651
Dommermuth, D.G., “A Parametric Study of the Electric Field in the Atmosphere due to the Transport of Space Charge Density by the Meandering Wind over the Ocean Surface,” ResearchGate preprint, Nov 2021. https://www.researchgate.net/publication/356002487

Maxima Scripts for Meandering Flows

Dommermuth, D.G., “Maxima Coding for Solving the Electric and Magnetic Fields due to the Transport of Space Charge Density over the Ocean Surface: New Evidence of an Inverse Energy Cascade in the Lower Atmosphere,” ResearchGate code, Sep 2021. https://www.researchgate.net/publication/354935522
Dommermuth, D.G., “A Maxima Script for Solving the Electric and Magnetic Fields due to Magnetic Induction by Meandering Flows in the Oceanic and Atmospheric Boundary Layers: New Evidence of an Inverse Energy Cascade in the Upper Ocean,” ResearchGate code, Oct 2021. https://www.researchgate.net/publication/355209396

Fortran Codes for Meandering Flows

Dommermuth, D.G., “A Fortran Code for Calculating Electric and Magnetic Fields due to the Transport of Space Charge Density by the Meandering Wind over the Ocean Surface: New Evidence of an Inverse Energy Cascade in the Lower Atmosphere,” ResearchGate code, Sep 2021. https://www.researchgate.net/publication/354935467
Dommermuth, D.G., “A Fortran Code for Calculating the Electric and Magnetic Fields due to Magnetic Induction by Meandering Flows in the Oceanic and Atmospheric Boundary Layers: New Evidence of an Inverse Energy Cascade in the Upper Ocean,” ResearchGate code, Oct 2021. https://www.researchgate.net/publication/355209298
Dommermuth, D.G., “F90 Coding for Calculating the Magnetic Fields due to Magnetic Induction by Meandering Drift Currents,” ResearchGate code, Oct 2021. https://www.researchgate.net/publication/355651566
Dommermuth, D.G., “F90 Coding for a Parametric Study of the Electric Field in the Atmosphere due to the Transport of Space Charge Density by the Meandering Wind over the Ocean Surface,” ResearchGate code, Nov 2021. https://www.researchgate.net/publication/356002311

The Effect of the Wind Drift on Wave Growth, Wave Breaking, and the Production of Turbulence

Dommermuth, D. G., “Comments on the Wave Energy Cascade, Part 3,” ResearchGate preprint, 2018. https://www.researchgate.net/publication/325036393
Dommermuth, D. G., “The Effect of Wind-Drift Currents on the Production of Turbulent Kinetic Energy During Wave Breaking,” ResearchGate preprint, 2018.
https://www.researchgate.net/publication/325139479
Dommermuth, D. G., “The Effect of Wind-Drift Currents on Near-Breaking Waves,” ResearchGate preprint, 2018. https://www.researchgate.net/publication/325273964
Dommermuth, D. G., “Breaking Waves and Wind in Equilibrium,” ResearchGate preprint, 2018. https://www.researchgate.net/publication/325883021

The Effect of Standing Waves on the Wave Energy Cascade

Dommermuth, D. G., “Comments on the Wave Energy Cascade,” arXiv:1710.09361v2[physics.ao-ph], 2017. https://arxiv.org/abs/1710.09361v2
Dommermuth, D. G., “Comments on the Wave Energy Cascade, Part 2,” ResearchGate preprint, 2018. https://www.researchgate.net/publication/324994196

Helmholtz Decompositions into Wavy and Vortical Portions

Dommermuth, D. G., “The laminar interactions of a pair of vortex tubes with a free surface,” J. Fluid Mech., Vol. 246, 1993, pp. 91–115. https://doi.org/10.1017/S0022112093000059
Mui, R. C. and Dommermuth, D. G., “The vortical structure of a near-breaking gravity-capillary wave,” Journal of Fluids Engineering, Vol. 117, 1994,355–361. https://doi.org/10.1115/1.2817269
Dommermuth, D. G., Novikov, E.A., and Mui, C.Y., “The Interaction of Surface Waves with Turbulence,” The Proceedings of the Symposium on Free-Surface Turbulence, ASME Fluids Engineering Division Summer Meeting, Lake Tahoe, California, USA, 1994. https://www.researchgate.net/publication/271527603

Entrainment and Mixing due to Plunging Breaking Waves

Brucker, K. A., O’Shea, T. T., Dommermuth, D. G., and Adams, P., “Three-dimensional simulations of deep-water breaking waves,” Proceedings of the 28th Symposium on Naval Hydrodynamics, Pasadena, California, USA, 2010. https://www.researchgate.net/publication/266619197
Dommermuth, D. G., “The Entrainment and Mixing of Air due to a Rectilinear Vortex Moving Parallel to a Free Surface,” ResearchGate preprint, Jun 2020. https://www.researchgate.net/publication/342247893

Numerical Methods

Dommermuth, D. G., “PID control of numerical simulations of breaking ocean waves,” ResearchGate preprint, Jan 2023. https://www.researchgate.net/publication/367569374