A model of the effects of horizontal density gradients on mixing processes in the oceanic surface layer

1996 ◽  
Vol 101 (C5) ◽  
pp. 12193-12208
Author(s):  
Gang Liu ◽  
Gerald S. Janowitz ◽  
Daniel Kamykowski
Keyword(s):  
Surface Layer ◽  
Density Gradients ◽  
Mixing Processes ◽  
Oceanic Surface

The warm oceanic surface layer: Implications for CO2fluxes and surface gas measurements

1996 ◽  
Vol 23 (24) ◽  
pp. 3575-3578 ◽  
Author(s):  
Craig L. McNeil ◽  
Liliane Merlivat
Keyword(s):  
Surface Layer ◽  
Oceanic Surface ◽  
Gas Measurements

scholarly journals Evaluating Monin-Obukhov Scaling in the Unstable Oceanic Surface Layer

2020 ◽  
Author(s):  
Zhihua Zheng ◽  
Ramsey R. Harcourt ◽  
Eric A. D’Asaro
Keyword(s):  
Surface Layer ◽  
Surface Waves ◽  
Scaling Laws ◽  
Similarity Theory ◽  
Vertical Mixing ◽  
Temperature Gradients ◽  
Langmuir Turbulence ◽  
Near Surface ◽  
Oceanic Surface ◽  
Using Data

AbstractMonin-Obukhov Similarity Theory (MOST) provides important scaling laws for flow properties in the surface layer of the atmosphere and has contributed to most of our understanding of the near-surface turbulence. The prediction of near-surface vertical mixing in most operational ocean models is largely built upon this theory. However, the validity of MOST in the upper ocean is questionable due to the demonstrated importance of surface waves in the region. Here we examine the validity of MOST in the statically unstable oceanic surface layer, using data collected from two open ocean sites with different wave conditions. The observed vertical temperature gradients are found to be about half of those predicted by MOST. We hypothesize this is attributable to either the breaking of surface waves, or Langmuir turbulence generated by the wave-current interaction. Existing turbulence closure models for surface wave breaking and for Langmuir turbulence are simplified to test these two hypotheses. Although both models predict reduced temperature gradients, the simplified Langmuir turbulence model matches observations more closely, when appropriately tuned.

Second Tesseral Harmonic Torque Due to the DynamicS of the Oceanic Surface Layer as Detected by TOPEX/POSEIDON Altimetry 1993-2000

2005 ◽  
Vol 49 (1) ◽  
pp. 13-22
Author(s):  
M. Burša ◽  
S. Kenyon ◽  
J. Kouba ◽  
Z. Šíma ◽  
V. Vatrt ◽  
...  
Keyword(s):  
Surface Layer ◽  
Oceanic Surface

Rapid removal of plutonium from the oceanic surface layer by zooplankton faecal pellets

Nature ◽  
1977 ◽  
Vol 266 (5603) ◽  
pp. 623-624 ◽  
Author(s):  
J. J. W. HIGGO ◽  
R. D. CHERRY ◽  
M. HEYRAUD ◽  
S. W. FOWLER
Keyword(s):  
Surface Layer ◽  
Faecal Pellets ◽  
Oceanic Surface ◽  
Rapid Removal

scholarly journals Intermittency of vertical density gradients at finescale and link with mixing processes

2004 ◽  
Vol 51 (25-26) ◽  
pp. 2919-2941 ◽  
Author(s):  
Pascale Bouruet-Aubertot ◽  
J. Sommeria ◽  
B. Le Cann ◽  
C.R. Koudella
Keyword(s):  
Density Gradients ◽  
Mixing Processes ◽  
Vertical Density

scholarly journals A Model for the Wind-Driven Current in the Wavy Oceanic Surface Layer: Apparent Friction Velocity Reduction and Roughness Length Enhancement

2018 ◽  
Vol 48 (11) ◽  
pp. 2721-2736 ◽  
Author(s):  
Miguel A. C. Teixeira
Keyword(s):  
Shear Stress ◽  
Surface Layer ◽  
Ocean Circulation ◽  
Friction Velocity ◽  
Roughness Length ◽  
Wave Spectrum ◽  
Surface Wind ◽  
Current Speed ◽  
Oceanic Surface ◽  
Wave Induced

AbstractA simple analytical model is developed for the current induced by the wind and modified by surface wind waves in the oceanic surface layer, based on a first-order turbulence closure and including the effect of a vortex force representing the Stokes drift of the waves. The shear stress is partitioned between a component due to shear in the current, which is reduced at low turbulent Langmuir number Lat, and a wave-induced component, which decays over a depth proportional to the dominant wavelength λw. The model reproduces the apparent reduction of the friction velocity and enhancement of the roughness length estimated from current profiles, detected in a number of studies. These effects are predicted to intensify as Lat decreases and are entirely attributed to nonbreaking surface waves. The current profile becomes flatter for low Lat owing to a smaller fraction of the total shear stress being supported by the current shear. Comparisons with the comprehensive dataset provided by the laboratory experiments of Cheung and Street show encouraging agreement, with the current speed normalized by the friction velocity decreasing as Lat decreases and λw increases if the model is adjusted to reflect the effects of a full wave spectrum on the intensity and depth of penetration of the wave-induced stress. A version of the model where the shear stress decreases to zero over a depth consistent with the measurements accurately predicts the surface current speed. These results contribute toward developing physically based momentum flux parameterizations for the wave-affected boundary layer in ocean circulation models.

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