Double-Diffusive Recipes. Part I: Large-Scale Dynamics of Thermohaline Staircases
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 and structure of the North Atlantic subtropical thermocline. Salt-finger transpor...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | en_US |
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American Meteorological Society
2014
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| Online Access: | http://hdl.handle.net/1721.1/91958 |
| _version_ | 1826190832930127872 |
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| author | Radko, T. Bulters, A. Flanagan, J. D. Campin, Jean-Michel |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Radko, T. Bulters, A. Flanagan, J. D. Campin, Jean-Michel |
| author_sort | Radko, T. |
| collection | MIT |
| description | 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 and structure of the North Atlantic subtropical thermocline. Salt-finger transport is parameterized using the flux-gradient formulation based on a suite of recent direct numerical simulations. Analysis of the spontaneous generation of thermohaline staircases suggests that thermohaline layering is a product of the gamma instability, associated with the variation of the flux ratio γ with the density ratio R[subscript p] . After their formation, numerical staircases undergo a series of merging events, which systematically increase the size of layers. Ultimately, the system evolves into a steady equilibrium state with pronounced layers 20–50 m thick. The size of the region occupied by thermohaline staircases is controlled by the competition between turbulent mixing and double diffusion. Assuming, in accordance with observations, that staircases form when the density ratio is less than the critical value of R[subscript cr] ≈ 1.7, the authors arrive at an indirect estimate of the characteristic turbulent diffusivity in the subtropical thermocline. |
| first_indexed | 2024-09-23T08:46:22Z |
| format | Article |
| id | mit-1721.1/91958 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T08:46:22Z |
| publishDate | 2014 |
| publisher | American Meteorological Society |
| record_format | dspace |
| spelling | mit-1721.1/919582022-09-23T14:25:56Z Double-Diffusive Recipes. Part I: Large-Scale Dynamics of Thermohaline Staircases Radko, T. Bulters, A. Flanagan, J. D. Campin, Jean-Michel Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Campin, Jean-Michel 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 and structure of the North Atlantic subtropical thermocline. Salt-finger transport is parameterized using the flux-gradient formulation based on a suite of recent direct numerical simulations. Analysis of the spontaneous generation of thermohaline staircases suggests that thermohaline layering is a product of the gamma instability, associated with the variation of the flux ratio γ with the density ratio R[subscript p] . After their formation, numerical staircases undergo a series of merging events, which systematically increase the size of layers. Ultimately, the system evolves into a steady equilibrium state with pronounced layers 20–50 m thick. The size of the region occupied by thermohaline staircases is controlled by the competition between turbulent mixing and double diffusion. Assuming, in accordance with observations, that staircases form when the density ratio is less than the critical value of R[subscript cr] ≈ 1.7, the authors arrive at an indirect estimate of the characteristic turbulent diffusivity in the subtropical thermocline. National Science Foundation (U.S.) (Grant OCE 1334914) National Science Foundation (U.S.) (Grant CBET 0933057) National Science Foundation (U.S.) (Grant ANT 0944536) 2014-12-01T16:42:59Z 2014-12-01T16:42:59Z 2014-05 2013-12 Article http://purl.org/eprint/type/JournalArticle 0022-3670 1520-0485 http://hdl.handle.net/1721.1/91958 Radko, T., A. Bulters, J. D. Flanagan, and J.-M. Campin. “Double-Diffusive Recipes. Part I: Large-Scale Dynamics of Thermohaline Staircases.” J. Phys. Oceanogr. 44, no. 5 (May 2014): 1269–1284. © 2014 American Meteorological Society en_US http://dx.doi.org/10.1175/jpo-d-13-0155.1 Journal of Physical Oceanography Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Meteorological Society American Meteorological Society |
| spellingShingle | Radko, T. Bulters, A. Flanagan, J. D. Campin, Jean-Michel Double-Diffusive Recipes. Part I: Large-Scale Dynamics of Thermohaline Staircases |
| title | Double-Diffusive Recipes. Part I: Large-Scale Dynamics of Thermohaline Staircases |
| title_full | Double-Diffusive Recipes. Part I: Large-Scale Dynamics of Thermohaline Staircases |
| title_fullStr | Double-Diffusive Recipes. Part I: Large-Scale Dynamics of Thermohaline Staircases |
| title_full_unstemmed | Double-Diffusive Recipes. Part I: Large-Scale Dynamics of Thermohaline Staircases |
| title_short | Double-Diffusive Recipes. Part I: Large-Scale Dynamics of Thermohaline Staircases |
| title_sort | double diffusive recipes part i large scale dynamics of thermohaline staircases |
| url | http://hdl.handle.net/1721.1/91958 |
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