Equilibration of weakly nonlinear salt fingers
MetadataShow full item record
An analytical model is developed to explain the equilibration mechanism of the salt finger instability in unbounded temperature and salinity gradients. The theory is based on the weakly nonlinear asymptotic expansion about the point of marginal instability. The proposed solutions attribute equilibration of salt fingers to a combination of two processes: (i) the triad interaction and (ii) spontaneous development of the mean vertical shear. The non-resonant triad interactions control the equilibration of linear growth for moderate and large values of Prandtl number (Pr) and for slightly unstable parameters. For small Pr and/or rigorous instabilities, the mean shear effects become essential. It is shown that, individually, neither the mean field nor the triad interaction models can accurately describe the equilibrium patterns of salt fingers in all regions of the parameter space. Therefore, we propose a new hybrid model, which represents both stabilizing effects in a single framework. The resulting solutions agree with the fully nonlinear numerical simulations over a wide range of governing parameters.
The article of record as published may be found at http://dx.doi.org/10.1017/S0022112009992552
RightsThis publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
Showing items related by title, author, creator and subject.
Dynamics, heat transport, spectral composition and acoustic signatures of mesoscale variability in the ocean Carvalho, Daniel Peixoto de (Monterey, California. Naval Postgraduate School, 2013-12);The general circulation of the global ocean is turbulent rather than laminar. Mesoscale eddies contribute to the transport of tracers like heat, salt, and oxygen, and affect large-scale ocean dynamics. The problem of ...
Radko, Timour (2005);A simple theory is developed for the equilibrium height of steps in a thermohaline staircase. The model is based on a linear stability analysis for a series of salt-finger interfaces, which reveals a tendency for the ...
Simeonov, Julian A.; Stern, Melvin E.; Radko, Timour = (2009);The amplification and equilibration of three-dimensional salt fingers in unbounded uniform vertical gradients of temperature and salinity is modeled with a Direct Numerical Simulation in a triply periodic computational ...