Diapycnal Diffusivity Inferred from Scalar Microstructure Measurements near the New England Shelf/Slope Front*

Rehmann, Chris R.; Duda, Timothy F.

doi:10.1175/1520-0485(2000)030<1354:ddifsm>2.0.co;2

Cited by 31 publications

(60 citation statements)

References 34 publications

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“…Below them was a two-axis electromagnetic current meter sensing the flow speed past the probes and the angle of attack of the platform, for data calibration and quality control purposes. Further discussion of the instruments and their performance is available in a journal article showing the results of earlier work with this system (Rehmann and Duda, 2000).…”

Section: Instrumentsmentioning

confidence: 99%

“…The figures show the timeseries of χ, color coded by stratification type (DS type, salt-finger double-diffusive instability type, and layering doublediffusive instability type), and also show the tow-yo undulations with color-coding of the stratification type. These calculation methods are described in Rehmann and Duda (2000), Section 2b.…”

Section: Thermal Variance Dissipation Rate χmentioning

confidence: 99%

“…Using processing code MT04 Version 8, flux as a function of density gradient is computed as described below. The methods used are very smilar to those used in Rehmann and Duda (2000) and Duda and Rehmann (2002).…”

Section: Gradient-dependent Flux Law Testingmentioning

confidence: 99%

“…The density ratio (see for example Schmitt, 1983) and Turner angle (see for example Rehmann and Duda, 2000) are also computed. Next, using the measured speed through the water, the conductivity gradient spectrum in spatial units is computed from the 400-Hz data.…”

Section: Gradient-dependent Flux Law Testingmentioning

confidence: 99%

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Microscale, finescale, and mesoscale measurements made during the 2004 Structured Mixing Project (Micro-Tow 04) Cruise

Duda¹,

Sellers²

2016

Self Cite

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A physical oceanographic sampling voyage was made with RV Endeavor during August 2004 to evaluate diapycnal mixing processes on the continental shelf south of Massachusetts and Rhode Island, USA. The goal of the project was to look for a relationship between intensity of microstructure (thermal variance dissipation rate) and finestructure (background temperature gradient), in so-called doubly-stable water, which would be indicative of a density gradientdependent diapycnal heat flux. To satisfy the requirement that a large amount of data be collected to constrain the statistically estimated result, a microstructure sensor was towed on a platform behind the ship, providing continuous sampling at the depths of interest. To obtain the necessary finestructure quantities the platform measured temperature, conductivity and depth with a standard pumped Seabird 9plus CTD. Attitude and speed of the platform were recorded to assure proper data quality.This report shows temperature, salinity, density, and sound speed in twenty-five tow-yo transects obtained using the towed unit. Only statistics and results from microscale data are shown. In waters with stable salt stratification and stable temperature stratification, a previously obtained empirical result of reduced flux at increased density gradient is supported by the data.

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Section: Instrumentsmentioning

confidence: 99%

Section: Thermal Variance Dissipation Rate χmentioning

confidence: 99%

Section: Gradient-dependent Flux Law Testingmentioning

confidence: 99%

Section: Gradient-dependent Flux Law Testingmentioning

confidence: 99%

See 2 more Smart Citations

Microscale, finescale, and mesoscale measurements made during the 2004 Structured Mixing Project (Micro-Tow 04) Cruise

Duda¹,

Sellers²

2016

Self Cite

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“…Since values of a between 0 and 3 have been identified in measurements in the ocean (Sarmiento et al 1976;Hoffert and Broecker 1978;Gargett and Holloway 1984;Rehmann and Duda 2000), we choose different values from this range in our experiments. Depending on the value of a, this parameterization results in 0:05Â10 À4 m 2 s À1 .…”

Section: Paramterization Of Vertical Mixingmentioning

confidence: 99%

Sensitivity of North Atlantic subpolar gyre and overturning to stratification-dependent mixing: response to global warming

Marzeion¹,

Levermann²,

Mignot³

2009

Clim Dyn

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We use a reduced complexity climate model with a three-dimensional ocean component and realistic topography to investigate the effect of stratificationdependent mixing on the sensitivity of the North Atlantic subpolar gyre (SPG), and the Atlantic meridional overturning circulation (AMOC), to idealized CO 2 increase and peaking scenarios. The vertical diffusivity of the ocean interior is parameterized as j * N -a , where N is the local buoyancy frequency. For all parameter values 0 B a B 3, we find the SPG, and subsequently the AMOC, to weaken in response to increasing CO 2 concentrations. The weakening is significantly stronger for a C a cr & 1.5. Depending on the value of a, two separate model states develop. These states remain different after the CO 2 concentration is stabilized, and in some cases even after the CO 2 concentration has been decreased again to the pre-industrial level. This behaviour is explained by a positive feedback between stratification and mixing anomalies in the Nordic Seas, causing a persistent weakening of the SPG.

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Turbulence in theEastChinaSea:The summertime stratification

et al. 2015

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A series of 134 microstructure profiles were taken in the central East China Sea from a drifting ship, covering more than 12 miles over the sloping bottom. The water depth z varied in the range 52-62 m; the tidal elevation of semidiurnal component was 61 m. Prior to the onset of 25 h drift, a hydrographic section consisting of 9 stations, 15 miles apart, was taken in the area. A shallow mixed surface layer (SL) underlain by a diurnal pycnocline (z < 13 m), a sharp thermohalocline (13 < z < 30 m), and about 20 m tall bottom boundary layer (BBL) were the main features of summertime stratification. The splitting of upper pycnocline by a warmer, saltier intrusion led to the generation of turbulent patches at the lower, but not at the upper, density interface of this water body, suggesting asymmetry of mixing across the intrusion. In a limited range of the normalized squared buoyancy frequency, 2 < N 2 =N 2 0 < 6:3, the turbulent kinetic energy dissipation rate e decreased sharply as e=e m 5 N 2 =N

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Diapycnal Diffusivity Inferred from Scalar Microstructure Measurements near the New England Shelf/Slope Front*

Cited by 31 publications

References 34 publications

Microscale, finescale, and mesoscale measurements made during the 2004 Structured Mixing Project (Micro-Tow 04) Cruise

Microscale, finescale, and mesoscale measurements made during the 2004 Structured Mixing Project (Micro-Tow 04) Cruise

Sensitivity of North Atlantic subpolar gyre and overturning to stratification-dependent mixing: response to global warming

Turbulence in theEastChinaSea:The summertime stratification

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