Acoustic Detection of Oceanic Double-Diffusive Convection: A Feasibility Study

Abstract The feasibility of using high-frequency acoustic scattering techniques to map the extent and evolution of the diffusive regime of double-diffusive convection in the ocean is explored. A scattering model developed to describe acoustic scattering from double-diffusive interfaces in the laboratory, which accounted for much of the measured scattering in the frequency range from 200 to 600 kHz, is used in conjunction with published in situ observations of diffusive-convection interfaces to make predictions of acoustic scattering from oceanic double-diffusive interfaces. Detectable levels of acoustic scattering are predicted for a range of different locations in the world’s oceans. To corroborate these results, thin acoustic layers detected near the western Antarctic Peninsula using a multifrequency acoustic backscattering system are shown to be consistent with scattering from diffusive-convection interfaces.

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Double diffusive convection in the diffusive regime

Applied Scientific Research ◽

10.1007/bf00389267 ◽

1982 ◽

Vol 39 (4) ◽

pp. 301-319 ◽

Cited By ~ 5

Author(s):

Sheng-Ming Chang ◽

Seppo A. Korpela ◽

Yee Lee

Keyword(s):

Double Diffusive Convection ◽

Diffusive Regime ◽

Diffusive Convection ◽

Double Diffusive

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An optical technique for the in-situ measurement of species concentration in double diffusive convection

International Communications in Heat and Mass Transfer ◽

10.1016/0735-1933(87)90003-0 ◽

1987 ◽

Vol 14 (1) ◽

pp. 3-10 ◽

Cited By ~ 6

Author(s):

M. Kazmierczak ◽

D. Poulikakos

Keyword(s):

In Situ Measurement ◽

Optical Technique ◽

Double Diffusive Convection ◽

Species Concentration ◽

Diffusive Convection ◽

Double Diffusive

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High‐frequency broadband acoustic scattering for investigating double‐ diffusive convection

The Journal of the Acoustical Society of America ◽

10.1121/1.2933395 ◽

2008 ◽

Vol 123 (5) ◽

pp. 3213-3213

Author(s):

Tetjana Ross ◽

Andone Lavery

Keyword(s):

High Frequency ◽

Acoustic Scattering ◽

Double Diffusive Convection ◽

Diffusive Convection ◽

Double Diffusive

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Layering and vertical transport in sheared double-diffusive convection in the diffusive regime

Journal of Fluid Mechanics ◽

10.1017/jfm.2021.1091 ◽

2021 ◽

Vol 933 ◽

Author(s):

Yantao Yang ◽

Roberto Verzicco ◽

Detlef Lohse ◽

C.P. Caulfield

Keyword(s):

Initial Perturbation ◽

Flux Ratio ◽

Vertical Transport ◽

Salt Flux ◽

Double Diffusive Convection ◽

Control Parameters ◽

Diffusive Regime ◽

Diffusive Convection ◽

Wide Range ◽

Double Diffusive

A sequence of two- and three-dimensional simulations are conducted for the double-diffusive convection (DDC) flows in the diffusive regime subjected to an imposed shear. For a wide range of control parameters, and for sufficiently strong perturbation of the conductive initial state, staircase-like structures spontaneously develop, with relatively well-mixed layers separated by sharp interfaces of enhanced scalar gradient. Such staircases appear to be robust even in the presence of strong shear over very long times, with early-time coarsening of the observed layers. For the same set of control parameters, different asymptotic layered states, with markedly different vertical scalar fluxes, can arise for different initial perturbation structures. The imposed shear significantly spatio-temporally modifies the vertical transport of the various scalars. The flux ratio $\gamma ^*$ (i.e. the ratio between the density fluxes due to the total salt flux and the total heat flux) is found, at steady state, to be essentially equal to the square root of the ratio of the salt diffusivity to the thermal diffusivity, consistent with the physical model proposed by Linden & Shirtcliffe (J. Fluid Mech., vol. 87, 1978, pp. 417–432) and the variational arguments presented by Stern (J. Fluid Mech., vol. 114, 1982, pp. 105–121) for unsheared double-diffusive convection.

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