Journal ArticleDOI
A theoretical model for horizontal convection at high Rayleigh number
TLDR
In this article, a simple flow model and solution to describe "horizontal convection" driven by a gradient of temperature or heat flux along one horizontal boundary of a rectangular box is presented.Abstract:
We present a simple flow model and solution to describe ‘horizontal convection’ driven by a gradient of temperature or heat flux along one horizontal boundary of a rectangular box. Following laboratory observations of the steady-state convection, the model is based on a localized vertical turbulent plume from a line or point source that is located anywhere within the area of the box and that maintains a stably stratified interior. In contrast to the ‘filling box’ process, the convective circulation involves vertical diffusion in the interior and a stabilizing buoyancy flux distributed over the horizontal boundary. The stabilizing flux forces the density distribution to reach a steady state. The model predictions compare well with previous laboratory data and numerical solutions. In the case of a point source for the plume (the case which best mimics the localized sinking in the large-scale ocean overturning) the thermal boundary layer is much thicker than that given by the two-dimensional boundary layer scaling of H. T. Rossby (Tellus, vol. 50, 1965, p. 242).read more
Citations
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The fluid mechanics of natural ventilation
TL;DR: In this paper, two forms of ventilation are discussed: mixing ventilation and displacement ventilation, where the interior is at an approximately uniform temperature and there is strong internal stratification, respectively, and the effects of wind on them are examined.
Journal ArticleDOI
Heat and momentum transport scalings in horizontal convection
TL;DR: In this paper, the authors proposed a theoretical model for heat and momentum transport scalings with Rayleigh number (Ra) which is based on the Grossmann and Lohse (2000) ideas, applied to HC flows.
Journal ArticleDOI
Stability transitions and turbulence in horizontal convection
TL;DR: In this article, the authors use three-dimensional direct numerical simulation (DNS) and large-eddy simulation (LES) over a wide range of Rayleigh numbers,, for Prandtl number and a small aspect ratio, and show that a sequence of several stability transitions at defines a change from laminar to turbulent flow.
Journal ArticleDOI
Horizontal convection: Effect of aspect ratio on Rayleigh number scaling and stability
Gregory J. Sheard,Martin P. King +1 more
TL;DR: In this article, the scaling of mean Nusselt number and boundary layer quantities with aspect ratio and Rayleigh number was investigated in a rectangular enclosure driven by a linear temperature profile along the bottom boundary.
Journal ArticleDOI
Very viscous horizontal convection
TL;DR: In this article, the infinite-Prandtl-number limit was studied for very viscous fluids, motivated by the study of convection in glass furnaces, and the authors considered a rectangular domain with insulating conditions on the sides and bottom, and a linear temperature gradient on the top.
References
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Book
Atmosphere-Ocean Dynamics
TL;DR: In this article, the authors describe how the Ocean-Atmosphere system is driven by transfer of properties between the atmosphere and the ocean. But they do not consider the effects of side boundaries.
Book
Climate Change 1995: The Science of Climate Change
TL;DR: The most comprehensive and up-to-date assessment available for scientific understanding of human influences on the past present and future climate is "Climate Change 1995: The Science of Climate Change" as mentioned in this paper.
Book
Buoyancy Effects in Fluids
TL;DR: In this article, the authors introduce linear internal waves and herar flows in a stratified fluid and double-diffusive convection in stably stratified fluids, and show that the shear flows can produce turbulence.
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
Evidence for slow mixing across the pycnocline from an open-ocean tracer-release experiment
Abstract: THE distributions of heat, salt and trace substances in the ocean thermocline depend on mixing along and across surfaces of equal density (isopycnal and diapycnal mixing, respectively). Measurements of the invasion of anthropogenic tracers, such as bomb tritium and 3He (see, for example, refs 1 and 2), have indicated that isopycnal processes dominate diapycnal mixing, and turbulence measurements have suggested that diapycnal mixing is small3,4, but it has not been possible to measure accurately the diapycnal diffusivity. Here we report such a measurement, obtained from the vertical dispersal of a patch of the inert compound SF6 released in the open ocean. The diapycnal diffusivity, averaged over hundreds of kilometres and five months, was 0.11 ± 0.02 cm2 s−1, confirming previous estimates1–4. Such a low diffusivity can support only a rather small diapycnal flux of nitrate into the euphotic zone; it justifies the neglect of diapycnal mixing in dynamic models of the thermocline25–27, and implies that heat, salt and tracers must penetrate the thermocline mostly by transport along, rather than across, density surfaces.