Journal ArticleDOI
Internal Tide Reflection and Turbulent Mixing on the Continental Slope
TLDR
In this article, it is suggested that elevated near-bottom mixing (Kρ ∼ 10−3 m2 s−1) observed offshore of the supercritical continental slope arises from the reflection of a remotely generated, low-mode, M2 internal tide.Abstract:
Observations of turbulence, internal waves, and subinertial flow were made over a steep, corrugated continental slope off Virginia during May–June 1998. At semidiurnal frequencies, a convergence of low-mode, onshore energy flux is approximately balanced by a divergence of high-wavenumber offshore energy flux. This conversion occurs in a region where the continental slope is nearly critical with respect to the semidiurnal tide. It is suggested that elevated near-bottom mixing (Kρ ∼ 10−3 m2 s−1) observed offshore of the supercritical continental slope arises from the reflection of a remotely generated, low-mode, M2 internal tide. Based on the observed turbulent kinetic energy dissipation rate ϵ, the high-wavenumber internal tide decays on time scales O(1 day). No evidence for internal lee wave generation by flow over the slope's corrugations or internal tide generation at the shelf break was found at this site.read more
Citations
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Journal ArticleDOI
Internal Tide Generation in the Deep Ocean
Chris Garrett,Eric Kunze +1 more
TL;DR: In this article, it was shown that most of the energy flux is associated with low modes that propagate away from the generation region, and that intensity beams of internal tidal energy are expected near critical slopes, bottom slopes equal to the ray slope.
Journal ArticleDOI
Global Abyssal Mixing Inferred from Lowered ADCP Shear and CTD Strain Profiles
TL;DR: In this paper, internal wave-wave interaction theories and observations support a parameterization for the turbulent dissipation rate e and eddy diffusivity K that depends on internal wave shear and strain variances.
Book
The Turbulent Ocean
TL;DR: The Turbulent Ocean as discussed by the authors describes the principal dynamic processes that control the distribution of turbulence, its dissipation of kinetic energy and its effects on the dispersion of properties such as heat, salinity, and dissolved or suspended matter in the deep ocean, the shallow coastal and the continental shelf seas.
Journal ArticleDOI
Global Patterns of Diapycnal Mixing from Measurements of the Turbulent Dissipation Rate
Amy F. Waterhouse,Jennifer A. MacKinnon,Jonathan D. Nash,Matthew H. Alford,Eric Kunze,Harper L. Simmons,Kurt L. Polzin,Louis St. Laurent,Oliver M. T. Sun,Robert Pinkel,Lynne D. Talley,Caitlin B. Whalen,T. N. Huussen,Glenn S. Carter,Ilker Fer,Stephanie Waterman,Alberto C. Naveira Garabato,Thomas B. Sanford,Craig M. Lee +18 more
TL;DR: In this article, the authors present inferences of diapycnal diffusivity from a compilation of over 5200 microstructure profiles, supplemented with indirect measurements of mixing obtained from (i) Thorpe-scale overturns from mooring profiles, (ii) shipboard observations of upper-ocean shear, (iii) strain as measured by profiling floats, and (iv) shear and strain from full-depth loweredacoustic Doppler currentprofilers (LADCP) and CTD profiles.
Journal ArticleDOI
Energy Flux and Dissipation in Luzon Strait: Two Tales of Two Ridges
Matthew H. Alford,Jennifer A. MacKinnon,Jonathan D. Nash,Harper L. Simmons,Andy Pickering,Jody M. Klymak,Robert Pinkel,Oliver M. T. Sun,Luc Rainville,Ruth Musgrave,Tamara Beitzel,Ke-Hsien Fu,Chung-Wei Lu +12 more
TL;DR: In this paper, the authors investigated internal tide generation, propagation, and dissipation in Luzon Strait, a system of two quasi-parallel ridges situated between Taiwan and the Philippines.
References
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Journal ArticleDOI
Global Sea Floor Topography from Satellite Altimetry and Ship Depth Soundings
TL;DR: In this paper, a digital bathymetric map of the oceans with a horizontal resolution of 1 to 12 kilometers was derived by combining available depth soundings with high-resolution marine gravity information from the Geosat and ERS-1 spacecraft.
Journal ArticleDOI
Abyssal recipes II: energetics of tidal and wind mixing
Walter Munk,Carl Wunsch +1 more
TL;DR: Using the Levitus climatology, the authors showed that 2.1 TW (terawatts) is required to maintain the global abyssal density distribution against 30 Sverdrups of deep water formation.
Journal ArticleDOI
Estimates of the Local Rate of Vertical Diffusion from Dissipation Measurements
TL;DR: In this article, two models for the source of oceanic turbulence are considered; namely, production by the Reynolds stress working against a time variable mean shear, and the gravitational collapse of Kelvin-Helmholtz instabilities.
Journal ArticleDOI
Scaling turbulent dissipation in the thermocline
Abstract: By comparing observations from six diverse sites in the mid-latitude thermocline, we find that, to within a factor of 2, 〈eIW〉=7×10‐10〈N2/N02〉〈S104/SGM4〉 W kg‐1, where 〈eIW〉 is the average dissipation rate attributable to internal waves; N0 = 0.0052 s−1 is a reference buoyancy frequency; S10 is the observed shear having vertical wavelengths greater than 10 m; and SGM is the corresponding shear in the Garrett and Munk spectrum of internal waves. The functional form agrees with estimates by McComas and Muller and by Henyey, Wright, and Flatte of the rate of energy transfer within the internal wave spectrum, provided the energy density of the internal waves is treated as a variable instead of one of the constant parameters. Following Garrett and Munk, we assume that 〈S104/SGM4〉=〈EIW2/EGM2〉, where EIW is the observed energy density and EGM is the energy density used by Garrett and Munk. The magnitude of eIW is twice that of Henyey et al. and one third that of McComas and Muller. Thus the observations agree with predictions sufficiently well to suggest that (1) a first-order understanding of the link between internal waves and turbulence has been achieved, although Henyey et al. made some ad hoc assumptions and Garrett and Munk's model does not match important features in the internal wave spectrum reported by Pinkel, and (2) the simplest way to obtain average dissipation rates over large space and time scales is to measure 〈N2/N02〉〈S104/SGM4〉. Even though the observations were taken at latitudes of 42°−11.5°, the variability in the Coriolis parameter ƒ was too limited for a conclusive test of the ƒ dependence also predicted for 〈eIW〉 by the wave-wave interaction models. An exception to the scaling occurs east of Barbados in the thermohaline staircase that is apparently formed and maintained by salt fingers. Although e in the staircase is very low compared with rates at mid-latitude sites, it is 8 times larger than predicted for e due only to internal waves.
Journal ArticleDOI
On internal tide generation models
TL;DR: In this article, a linear generation model for internal tides over large topographic features such as continental slopes is discussed, with the objects of making the procedures simpler and more adaptable to oceanic situations than heretofore.