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Journal ArticleDOI

Wave-induced mixing in the upper ocean: Distribution and application to a global ocean circulation model

01 Jun 2004-Geophysical Research Letters (John Wiley & Sons, Ltd)-Vol. 31, Iss: 11
TL;DR: In this article, the wave-induced vertical viscosity (or diffusivity) Bv is defined, which can be used as a parameter to estimate the strength of waveinduced mixing.
Abstract: [1] From the Reynolds stress expression, the wave-induced vertical viscosity (or diffusivity) Bv is defined, which can be used as a parameter to estimate the strength of wave-induced mixing. In addition, a parameter D5 is introduced to represent a wave-induced mixing penetration depth. The global distribution of Bv averaged over the upper 20 m is calculated and its latitudinal transects in boreal summer and winter is discussed. The results show that in summer the wave-induced mixing is strong in the southern oceans south of 30°S, and in winter it is strong in the north Pacific and the north Atlantic north of 30°N, as well as in the southern oceans south of 40°S. Adding Bv to the vertical diffusivity in a global ocean circulation model yields a temperature structure in the upper 100 m that is closer to the observed climatology than a model without the wave-induced mixing.
Citations
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Journal ArticleDOI
TL;DR: The Beijing Climate Center Climate System Model (BCC_CSM) and its four component models (atmosphere, land surface, ocean, and sea ice) are described in this article.
Abstract: This paper reviews recent progress in the development of the Beijing Climate Center Climate System Model (BCC_CSM) and its four component models (atmosphere, land surface, ocean, and sea ice). Two recent versions are described: BCC_CSM1.1 with coarse resolution (approximately 2.8125°×2.8125°) and BCC_CSM1.1(m) with moderate resolution (approximately 1.125°×1.125°). Both versions are fully coupled climate-carbon cycle models that simulate the global terrestrial and oceanic carbon cycles and include dynamic vegetation. Both models well simulate the concentration and temporal evolution of atmospheric CO2 during the 20th century with anthropogenic CO2 emissions prescribed. Simulations using these two versions of the BCC_CSM model have been contributed to the Coupled Model Intercomparison Project phase five (CMIP5) in support of the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5). These simulations are available for use by both national and international communities for investigating global climate change and for future climate projections. Simulations of the 20th century climate using BCC_CSM1.1 and BCC_CSM1.1(m) are presented and validated, with particular focus on the spatial pattern and seasonal evolution of precipitation and surface air temperature on global and continental scales. Simulations of climate during the last millennium and projections of climate change during the next century are also presented and discussed. Both BCC_CSM1.1 and BCC_CSM1.1(m) perform well when compared with other CMIP5 models. Preliminary analyses indicate that the higher resolution in BCC_CSM1.1(m) improves the simulation of mean climate relative to BCC_CSM1.1, particularly on regional scales.

257 citations

Journal ArticleDOI
TL;DR: In this paper, a wave-amplitude-based Reynolds number is suggested to indicate a transition from laminarity to turbulence for the wave-induced motion, and the depth of upper ocean mixing due to wave-generated turbulence can be predicted based on knowledge of the wave climate.
Abstract: [1] A concept of wave-amplitude-based Reynolds number is suggested which is hypothesised to indicate a transition from laminarity to turbulence for the wave-induced motion If the hypothesis is correct, the wave-induced motion can be turbulent and the depth of upper ocean mixing due to such wave-generated turbulence can be predicted based on knowledge of the wave climate Estimates of the critical wave Reynolds number provide an approximate value of Recr = 3000 This number was tested on mechanically-generated laboratory waves and was confirmed Once this number is used for ocean conditions when mixing due to heating and cooling is less important than that due to the waves, quantitative and qualitative characteristics of the ocean's Mixed Layer Depth (MLD) are shown to be predicted with a satisfactory degree of agreement with observations Testing the hypothesis against other known results in turbulence generation and wave attenuation is also conducted

164 citations

Journal ArticleDOI
TL;DR: In this article, the effects of thermocline shoaling on the ocean internal wave (IW) generation in the north South China Sea (NSCS) were analyzed using seven years of satellite synthetic aperture radar (SAR) images from 1995 to 2001.
Abstract: [1] This study analyzes the effects of thermocline shoaling on the ocean internal wave (IW) generation in the north South China Sea (NSCS). Seven years of satellite synthetic aperture radar (SAR) images from 1995 to 2001 are used for the statistical analysis of IW occurrence, and field measurements of sea surface wind, sea state, and vertical temperature profiles are used for analyzing IW generation and SAR imaging conditions. Latitudinal distribution of IW packets shows that 22% of IW packets distributed in the east of 118E obviously originate from the Luzon Strait, and 78% of IW packets west of 118E may propagate from the east or evolve into the solitons originating from the east boundary owing to the fission effect of shoaling thermocline. The yearly distribution of IW occurrence frequencies reveals an interannual variability, implying that there are long-term and large-scale processes modifying the SAR-observed IW occurrence. The monthly SAR-observed IWoccurrence frequencies show that the high frequencies are distributed from April to July and reach a peak in June with a maximum frequency of 20%. The low occurrence frequencies are distributed in winter from December to February of next year with a minimum frequency of 1.5% in February. This study proposes that the IW generation needs the necessary and sufficient conditions: initial disturbance formation and wave amplitude growth. Owing to the dissipation effect on the initial disturbance, only fully grown waves have a chance to radiate out of the source region. A physical model and PKdVequation are adopted for analyzing the sufficient conditions for solitary IW amplitude growth. The results indicate that the thermocline shoaling provides the forcing to soliton amplitude growth, so that the soliton amplitude growth ratio (SAGR) serves as a decisive factor for the IW occurrence frequency. Theoretical analysis predicts a linear relation between the two. Application of theoretical models to field measurements in the Luzon Strait gives a correlation coefficient as high as 0.845 with a confidence level of 99% for months from March to November. The linear regression gives a correlation coefficient (R 2 ) of 0.6519 and a SAGR threshold (minimum) value of

153 citations


Cites background from "Wave-induced mixing in the upper oc..."

  • ...In a real ocean, however, the dissipation induced by the eddy viscosity and bottom friction [Liu et al., 2004], and wave-induced mixing in the upper ocean [Qiao et al., 2004] always exist....

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Journal ArticleDOI
TL;DR: Although a review of measurements finds strong support for the influence of waves-and, in particular, for the predictions of large-eddy simulations, including the Craik-Leibovich vortex force-there are insufficient data to give definitive support to a new paradigm.
Abstract: Nearly all operational models of upper-ocean mixing assume that the turbulence responsible for this mixing is driven by the atmospheric fluxes of momentum, heat, and moisture and the shear imposed by the ocean circulation. This idealization is supported by historical measurements of dissipation rate within the boundary layer. Detailed measurements made recently by many investigators and supported by theoretical and numerical results have found significant deviations from this classical view attributable to the influence of surface waves. Although a review of these measurements finds strong support for the influence of waves-and, in particular, for the predictions of large-eddy simulations, including the Craik-Leibovich vortex force-there are insufficient data to give definitive support to a new paradigm.

151 citations


Cites background from "Wave-induced mixing in the upper oc..."

  • ...Quantification of this effect (Huang & Qiao 2010, Qiao et al. 2004) relies on mixing length arguments to specify a viscosity ∼l2S, where the mixing length l is taken as www.annualreviews.org • Turbulence in the Upper-Ocean Mixed Layer 4.9 Changes may still occur before final publication online and…...

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Journal ArticleDOI
TL;DR: In this paper, the three-dimensional structure of the summertime circulation of the Yellow Sea (hereafter YS) was studied by using a prognostic wave-tide-circulation coupled model based on the Princeton Ocean Model (POM) and a surface wave model.
Abstract: [1] The three-dimensional structure of the summertime circulation of the Yellow Sea (hereafter YS) is studied by using a prognostic wave-tide-circulation coupled model based on the Princeton Ocean Model (POM) and a surface wave model. The simulated tidal harmonic constants and temperature structure agree with the observations well. The patterns of the simulated salinity generally agree also with the observations. The simulated results show that the horizontal circulation has a three-layer structure: in the surface layer (0–4 m), the prevailing current direction is northeastward; in the upper layer (4–40 m) it is dominated by a basin scale anticlockwise (cyclonic) gyre; in the bottom layer (below 40 m) the water diverges from the center area and there exists a weak southward current along the YS trough. The stream function of the YS shows that the net circulation of the YS is an anticlockwise (cyclonic) one, and the net transport is about 0.1 Sv. Diagnostic analysis of the momentum balance and sensitivity show that the cyclonic circulation in the upper layers is mainly a quasi-geostrophic flow along tidal-induced temperature front, and it is also strengthened by the tide residual currents. The tidal residual current and the compensation for northward surface layer wind transport contribute to the formation of southward flow in the bottom layer. The vertical circulations vary along different sections. A circulation cell is found in the frontal area near the Korean coast, and an upwelling is found along the slope.

147 citations


Additional excerpts

  • ...An additional wave-induced mixing Bv is computed by the MASNUM wave model and added to the vertical viscosity KM and diffusivity KH calculated by M-Y scheme in POM [ Qiao et al., 2004a, 2004b ]....

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References
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Journal ArticleDOI
TL;DR: The second-moment turbulent closure hypothesis has been applied to geophysical fluid problems since 1973, when genuine predictive skill in coping with the effects of stratification was demonstrated as discussed by the authors.
Abstract: Applications of second-moment turbulent closure hypotheses to geophysical fluid problems have developed rapidly since 1973, when genuine predictive skill in coping with the effects of stratification was demonstrated. The purpose here is to synthesize and organize material that has appeared in a number of articles and add new useful material so that a complete (and improved) description of a turbulence model from conception to application is condensed in a single article. It is hoped that this will be a useful reference to users of the model for application to either atmospheric or oceanic boundary layers.

6,488 citations


"Wave-induced mixing in the upper oc..." refers methods in this paper

  • ...Ezer [2000] simulated ML more realistically by including shortwave radiation penetration together with improving parameterization of dissipation in the Mellor-Yamada scheme [Mellor and Yamada, 1982]....

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01 Jan 1982
TL;DR: A project to objectively analyze historical ocean temperature, salinity, oxygen, and percent oxygen saturation data for the world ocean has recently been completed at the National Oceanic and Atmospheric Administration's (NOAA) Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey.
Abstract: A project to objectively analyze historical ocean temperature, salinity, oxygen, and percent oxygen saturation data for the world ocean has recently been completed at the National Oceanic and Atmospheric Administration's (NOAA) Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey. The results of the project are being made available through distribution of the Climatological Atlas of the World Ocean (NOAA Professional Paper No. 13), and through distribution of magnetic tapes containing the objective analyses. The sources of data used in the project were the Station Data, Mechanical Bathythermograph, and Expendable Bathythermograph files of the National Oceanographic Data Center (NODC) in Washington, D.C., updated through 1977–1978. The raw data were subjected to quality control procedures, averaged by one-degree squares, and then used as input to an objective analysis procedure that fills in one-degree squares containing no data and smooths the results. Due to the lack of synoptic observations for the world ocean, the historical data are composited by annual, seasonal, and (for temperature) monthly periods.

3,029 citations

Book
01 Jun 1982
TL;DR: A project to objectively analyze historical ocean temperature, salinity, oxygen, and percent oxygen saturation data for the world ocean has recently been completed at the National Oceanic and Atmospheric Administration's (NOAA) Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey.
Abstract: A project to objectively analyze historical ocean temperature, salinity, oxygen, and percent oxygen saturation data for the world ocean has recently been completed at the National Oceanic and Atmospheric Administration's (NOAA) Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey. The results of the project are being made available through distribution of the Climatological Atlas of the World Ocean (NOAA Professional Paper No. 13), and through distribution of magnetic tapes containing the objective analyses. The sources of data used in the project were the Station Data, Mechanical Bathythermograph, and Expendable Bathythermograph files of the National Oceanographic Data Center (NODC) in Washington, D.C., updated through 1977–1978. The raw data were subjected to quality control procedures, averaged by one-degree squares, and then used as input to an objective analysis procedure that fills in one-degree squares containing no data and smooths the results. Due to the lack of synoptic observations for the world ocean, the historical data are composited by annual, seasonal, and (for temperature) monthly periods.

2,929 citations

Journal ArticleDOI
04 Apr 1997-Science
TL;DR: Ocean microstructure data show that turbulent mixing in the deep Brazil Basin of the South Atlantic Ocean is weak at all depths above smooth abyssal plains and the South American Continental Rise, which implies that abyssal circulations have complex spatial structures that are linked to the underlying bathymetry.
Abstract: Ocean microstructure data show that turbulent mixing in the deep Brazil Basin of the South Atlantic Ocean is weak at all depths above smooth abyssal plains and the South American Continental Rise. The diapycnal diffusivity there was estimated to be less than or approximately equal to 0.1 x 10(-4) meters squared per second. In contrast, mixing rates are large throughout the water column above the rough Mid-Atlantic Ridge, and the diffusivity deduced for the bottom-most 150 meters exceeds 5 x 10(-4) meters squared per second. Such patterns in vertical mixing imply that abyssal circulations have complex spatial structures that are linked to the underlying bathymetry.

1,038 citations


"Wave-induced mixing in the upper oc..." refers background in this paper

  • ...[10] Recent studies on deep ocean mixing indicate that 2–4 cm2 s 1 are a threshold for a mixing process to play a role in vertical water mass transport [Ledwell et al., 2000; Polzin et al., 1997]....

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  • ...[10] Recent studies on deep ocean mixing indicate that 2–4 cm(2) s 1 are a threshold for a mixing process to play a role in vertical water mass transport [Ledwell et al., 2000; Polzin et al., 1997]....

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