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Powerpoint Files

I provide here links to PowerPoint files that are stored on iCloud.

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Free-Surface Curvature and Vorticity

Dommermuth, D. G., “The Entrainment and Mixing of Air due to a Rectilinear Vortex Moving Parallel to a Free Surface,” ResearchGate preprint, 5 Jun. 2020a. https://www.researchgate.net/publication/342247893.
Dommermuth, D. G., “The Ocean’s Heartbeat,” ResearchGate preprint, 20 Dec. 2020g. https://www.researchgate.net/publication/347514163.
Dommermuth, D. G., “Spilling Breaking Ocean Waves and Inverse Energy Cascades,” ResearchGate preprint, 1 Jan. 2021a. https://www.researchgate.net/publication/348136300.
Dommermuth, D. G., “Frequency Downshifting and Inverse Energy Cascades,” ResearchGate preprint, 12 Jan. 2021b. https://www.researchgate.net/publication/348419601.
Dommermuth, D. G., “Knots and Streaks – Where to Find Them,” ResearchGate preprint, 18 Jan. 2021c. https://www.researchgate.net/publication/348578523.
Dommermuth, D. G., “Whitecaps, Inverse Energy Cascades, and Energy Budgets,” ResearchGate preprint, 14 Apr. 2021d. https://www.researchgate.net/publication/350874498.
Dommermuth, D. G., “Modeling the Ocean’s Heartbeat,” ResearchGate preprint, 15 Jun. 2021f. https://www.researchgate.net/publication/352410045.
Dommermuth, D.G., “The Ocean’s Heartbeat,” Proceedings of WISE Workshop, Bergen, Norway, 2 Sep. 2021q. https://www.researchgate.net/publication/354152802.
Dommermuth, D.G., “The Ocean’s Heartbeat: An Inverse Energy Cascade that Mixes the Lower Atmosphere and Upper Ocean,” Proceedings of 34th Symposium on Naval Hydrodynamics Washington, D.C., June 26 – July 1, 2022. https://www.researchgate.net/publication/361643897.
Xuan, A. and Shen, L., “Analyses of wave-phase variation of reynolds shear stress underneath surface wave using streamline coordinates,” Journal of Fluid Mechanics, Vol. 931, 2022, p. A32. https://www.researchgate.net/publication/356704502

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Linear Growth of Energy

  1. Dommermuth, D. G., “The Ocean’s Heartbeat,” ResearchGate preprint, 20 Dec. 2020g. https://www.researchgate.net/publication/347514163.
  2. Dommermuth, D.G., “The Ocean’s Heartbeat,” Proceedings of WISE Workshop, Bergen, Norway, 2 Sep. 2021q. https://www.researchgate.net/publication/354152802.
  3. Dommermuth, D.G., “The Ocean’s Heartbeat: An Inverse Energy Cascade that Mixes the Lower Atmosphere and Upper Ocean,” Proceedings of 34th Symposium on Naval Hydrodynamics Washington, D.C., June 26 – July 1, 2022. https://www.researchgate.net/publication/361643897.
  4. Li, T. and Shen, L., “The principal stage in wind-wave generation,” Journal of Fluid Mechanics, Vol. 934, 2022, p. A41. https://www.researchgate.net/publication/357942664.

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PowerPoint Presentations on the Ocean’s Heartbeat

Large PowerPoint files are difficult to upload to ResearchGate. I provide here links to PowerPoint files that are stored on iCloud.

  1. Dommermuth, D. G., “The Ocean’s Heartbeat: An Inverse Energy Cascade that Mixes the Lower Atmosphere and Upper Ocean,” Powerpoint Presentation at Air-Sea Interactions and Implications for Offshore Wind Energy, February 10-11, 2022. DOI: 10.13140/RG.2.2.19506.07369. (1.9GB) https://www.icloud.com/iclouddrive/077831JwSj0nUAZ3rOTW-aJwA#dommermuth_airsea_10Feb22
  2. Dommermuth, D. G., “An Overview of the Ocean’s Heartbeat,” PowerPoint Presentation at The 28th Wind waves in the Earth System (WISE) Meeting, Brest, France, May 29 – June 2, 2022. DOI: 10.13140/RG.2.2.30526.36164. (526MB) https://www.icloud.com/iclouddrive/0adCmXBGtwob8ZlSZN_M3WaNQ#dommermuth_wise_2Jun22
  3. Dommermuth, D. G., “The Ocean’s Heartbeat: An Inverse Energy Cascade that Mixes the Lower Atmosphere and Upper Ocean,” PowerPoint Presentation at 34th Symposium on Naval Hydrodynamics Washington, D.C., June 26 – July 1, 2022. DOI: 10.13140/RG.2.2.17840.23047. (632MB) https://www.icloud.com/iclouddrive/0a09JyTSgZLvW-UlL_3EFwamA#dommermuth_34th_ONR_29Jun22
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The Ocean’s Heartbeat: An Inverse Energy Cascade that Mixes the Lower Atmosphere and Upper Ocean

Oblique-wave instabilities affect spilling breaking waves when the local wave steepness exceeds H/λ_o > 0.08, where H is the height and λ_o is the wavelength. Close to the ocean surface, spilling breaking waves resonate with Langmuir circulations in both the atmosphere and ocean. Away from the ocean surface, larger Langmuir circulations form under the action of inverse energy cascades. Surface currents due to Langmuir circulations and surfing effects due to spilling breaking waves affect the formation of windrows. The formation of meandering flows with broad spatial and temporal scales affects mixing in the atmosphere and ocean. Meandering drift currents have spatial and temporal scales conducive to the formation of internal waves in the ocean.

https://www.researchgate.net/publication/361643897

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Modeling the Ocean’s Heartbeat

Wave breaking affects turbulent fluctuations close to the free surface in the atmosphere and ocean. Away from the free surface, the large coherent structures that form through an inverse energy cascade in the atmosphere and ocean are not very sensitive to wave breaking. The formation of windrows is affected by the surfing and scrubbing actions of spilling breaking waves (Dommermuth, 2020f,g) and the surface currents that are induced by coherent structures transverse to the wind (Langmuir, 1938). Recent videos of windrows are suggestive of the complex interplay that can occur between wave breaking and surface currents (Tunli, 2021a,b,c,d,e).

https://www.researchgate.net/publication/352410045

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An Annotated Bibliography of the Ocean’s Heartbeat

Dommermuth (2020) shows that Langmuir circulations form under the action of an inverse energy cascade. 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. Windrows are visible manifestations of the inverse energy cascade. The vortical portion of the flow and spilling breaking waves work in combination to generate windrows. Breaking waves generate meandering currents and winds in the oceanic and atmospheric boundary layers. This report provides an annotated bibliography of research on the Ocean’s Heartbeat.

https://www.researchgate.net/publication/351234250

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The Ocean’s Heartbeat

The effects of the Ocean’s Heartbeat on the ocean and atmosphere are profound. My ultimate aim is to help establish a research group to study the Ocean’s Heartbeat using petascale supercomputing resources. Data assimilation will be used to nudge iLES of two-phase flows with VOF interface capturing to improve our understanding of the Ocean’s Heartbeat. I also feel that it is important to lay the foundation for graduate studies in this research area. I welcome opportunities to work with research groups from other countries. If you share my vision, contact me at [email protected].

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Whitecaps, Inverse Energy Cascades, and Energy Budgets

https://www.researchgate.net/publication/350874498

Ocean waves induce vortical flows in the oceanic and atmospheric boundary through an inverse energy cascade. Depending on the growth rate, the energy density in the vortical portion of the flow is about 6-10% of the wave kinetic energy. I call the mechanics of the energy transfer the Ocean’s Heartbeat (Dommermuth, 2020g). The depths and heights of the computational domain are currently 1/2 a wavelength, but the vortical portion of the flow will diffuse higher into the atmosphere and deeper into the ocean. Over 50-100 wave periods, large-scale coherent structures fill the width of the computational domain, which at present is no greater than one wavelength wide due to the limits of my computational resources. The length of the computational domain should be greater than two wavelengths to permit interactions between successive whitecaps. There are strong interactions between the vortical and wavy portions of the flow that induce whitecaps. The shedding of vorticity out the back of whitecaps feeds the vortical portion of the flow. This study of the energy density of the vortical portion of the flow is driven by atmospheric forcing. Another study of the energy density is underway whereby log profiles of the wind and wind drift are imposed using data assimilation.

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Knots and Streaks – Where to Find Them

https://www.researchgate.net/publication/348578523

Knots, upwellings, and streaks form in the wakes of spilling breaking waves. Knots are due to the shedding of intense monopoles, dipoles, tripoles, and quadrupoles (Dommermuth, 2021a,b). Upwellings are due to eddys and vortex rings (Dommermuth, 2021b). Streaks of foam collect in interstitial regions where vorticity of opposite sign connects normal to the free surface (Dommermuth, 2020g). Knots, upwellings, and streaks are visible in Fitzpatrick’s (2014) YouTube video of a North Sea storm. Fitzpatrick’s (2014) video is annotated and comparisons are made to Dommermuth (2020c,g, 2021a,b)’s numerical simulations. The presence of knots in storm seas provides evidence that an inverse energy cascade is present in spilling breaking waves.