Structure and evolution of thermohaline staircases in tropical North Atlantic
Wall, Steven E.
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This study explores the dynamics of salt finger convection which occurs when warm, salty water overlies cool and fresh. Salt finger convection is generally observed in mid-latitude regions, particularly in the Atlantic Ocean and Mediterranean Sea, between the base of the mixed layer and the top of the intermediate water. Active salt fingering is characterized by the appearance of well mixed layers separated by thin high-gradient interfaces, known as thermohaline staircases. The data from the CSALT, SFTRE and moored profiler experiments are analyzed to determine the origin of the thermohaline staircases and the mechanism for selection of the preferred layer thickness. Comparisons between these observations and models suggested by Radko are made. We use a combination of data analysis and analytical considerations to estimate the vertical heat/salt mixing rates and their dependencies on the large-scale environmental parameters. The three dimensional structure of these staircases and their evolution in time is explained by considering the secondary instabilities of a series of diffusive interfaces and the temporal and spatial structure of the high resolution data. Using a Parabolic Equation model we have investigated the influence of thermohaline staircases on acoustic propagation Also we experiment the sensitivity of the acoustic variations to changes in frequency and source depth.
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Radko, T.; Butlers, A.; Flanagan, J.D.; Campin, J.-M. (2014-05);Three-dimensional dynamics of thermohaline staircases are investigated using a series of basin-scale staircase-resolving numerical simulations. The computational domain and forcing fields are chosen to reflect the size ...
Three-dimensional structure of thermohaline staircases in the tropical north Atlantic and their effect on acoustic propagation Bulters, Amy C. (Monterey, California. Naval Postgraduate School, 2012-12);Under typical conditions in the subtropical thermocline double-diffusion occurs in the form of salt fingering (warm, salty fluid overlies cold, fresh fluid). The formation of staircases in the thermohaline structure of the ...
Tubbs, William D. (Monterey, CA; Naval Postgraduate School, 2018-12);Double diffusive convection through Arctic staircases has been shown to play a role in the melting of Arctic sea ice. However, there have been no studies exploring the effects of shear on these staircases. We simulated ...