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Peter P. Sullivan, Leonel Romero, James C. McWilliams, and W. Kendall Melville

-order moment of vertical velocity indicates an abundance of Langmuir cells, and is important as it appears in the turbulent kinetic energy equation. The changes in indicate that Langmuir turbulence has modified the vertical transport, the divergence , in the OBL in significant ways ( Grant and Belcher 2009 ). We find that the moments 〈 w 2 〉 max and are stronger and clearer indicators of Langmuir circulations than the nondimensional skewness , which is often used to describe Langmuir turbulence (e

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C. E. Grosch and A. E. Gargett

1. Introduction Langmuir supercells, wind-/wave-driven full-depth Langmuir circulation (LC) in homogeneous water columns, were first discovered in observations from the LEO15 cabled coastal observatory ( Gargett et al. 2004 ; Gargett and Wells 2007 ) off New Jersey, where they occur under storm conditions with winds from the northeast. As long as the wind/wave forcing remained quasi-steady in magnitude and direction, LS structures in this shallow shelf environment were found to be steady (when

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Jinliang Liu, Jun-Hong Liang, James C. McWilliams, Peter P. Sullivan, Yalin Fan, and Qin Chen

traps the Ekman transport within a relatively shallow mixed layer, which also limits the exchange of materials inside and outside the boundary layer. Surface gravity waves are ubiquitous over the global ocean. They drive coherent Langmuir circulations (LCs; or Langmuir turbulence) that modify the mean currents, mixing, and dissipation profiles (e.g., Sullivan et al. 2007 ; Belcher et al. 2012 ). LCs were first observed by Langmuir (1938) , later theoretically modeled by Craik and Leibovich (1976

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SEPTEMBER 1994 W U 1965 , 1984: The effect of Langmuir circulation on the distribution of submerged bubbles caused by breaking wind waves. J. Fluid Mech., 142, 151-170.--, 1986: Measurements with an automatically recording inverted echo sounder; ARIES and the bubble clouds. J. Phys. Oceanogr., 16, 1462-1478.--, and P. N. Humphries, 1980: Bubbles and breaking waves

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Anand Gnanadesikan and Robert A. Weller

reflectuncertainties in the physics of present parameterizations of rnixing within the mixed layer. This paper suggests that the models may fail to' reproduce the shear structure because they do not properly include the effects of large eddies (Langmuir circulations) within the mixed layer. While such large eddies are capable of homogenizing the mixed layerrelative to the highly sheared profile predicted by theMY2 model, they do not mix it completely and instantaneously as predicted by slab models. As a result

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Jun-Hong Liang, Xiaoliang Wan, Kenneth A. Rose, Peter P. Sullivan, and James C. McWilliams

Stokes–Coriolis term (e.g., Polton et al. 2005 ). When with a substantial along-wind component, they also interact with the currents and generate Langmuir circulation that penetrates the boundary layer (e.g., D’Asaro 2014 ), resulting in vertical diffusivity larger than in shear-driven Ekman turbulence through the boundary layer (e.g., McWilliams and Sullivan 2000 ). Breaking waves impact the vertical profiles of horizontal currents and vertical diffusivity, mainly close to the surface (e

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Ann E. Gargett

contaminated by vehicle motion, hence nothing could be deduced about their degree of isotropy. Anisotropy of energy-containing scales with < is the most likely oceanic norm, so in general and a choice of horizontal rather than vertical length scale does matter. How much can it matter? To illustrate, I consider Langmuir supercells ( Gargett et al. 2004 ; Gargett and Wells 2007 ), full-depth Langmuir circulations that are the energy-containing eddies of turbulence in shallow coastal seas during

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Fabrice Veron, W. Kendall Melville, and Luc Lenain

Melville 1990 ; Agrawal et al. 1992 ; Thorpe 1993 ; Melville 1994 ; Anis and Moum 1995 ; Melville 1996 ; Terray et al. 1996 ; Veron and Melville 1999a ), which along with small-scale Langmuir circulations and coherent structures ( Melville et al. 1998 ; Veron and Melville 1999b ; McWilliams et al. 1997 ; Veron and Melville 2001 ; Sullivan et al. 2004 , 2007 ), may lead to enhanced dissipation and mixing with significant departures from the “law of the wall” and may also result in increased

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Tyler J. Rabe, Tobias Kukulka, Isaac Ginis, Tetsu Hara, Brandon G. Reichl, Eric A. D’Asaro, Ramsey R. Harcourt, and Peter P. Sullivan

turbulence through their interaction with the sheared Eulerian currents. Specifically, the phase-averaged effects of surface gravity waves lead to a net drift (Stokes drift) that tilts vertical vorticity into the direction of wave propagation, creating wind-aligned roll vortices called Langmuir circulations ( Langmuir 1938 ). Craik and Leibovich (1976) , and later McWilliams et al. (2004) , developed the mathematical theory describing Langmuir circulations based on wave current interactions. The

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Andrey Pleskachevsky, Mikhail Dobrynin, Alexander V. Babanin, Heinz Günther, and Emil Stanev

dedicated to a key element of this paper, explaining and justifying the implementation of the nonbreaking turbulent diffusion produced by waves in circulation models. This implementation is then conducted and verified in section 4 , where two experiments are considered and modeled. The first example is a laboratory test with the observed mixing in a wave tank, where the wave motion is the only energy source (other effects such as those caused by wind-induced currents, Langmuir circulation, etc., are

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