Convection Enhances Mixing in the Southern Ocean
Mixing efficiency is a measure of the energy lost to mixing compared to that lost to viscous dissipation. In a turbulent stratified fluid the mixing efficiency is often assumed constant at ???? = 0.2, whereas with convection it takes values closer to 1. The value of mixing efficiency when both strat...
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ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/163982 2024-01-14T10:10:49+01:00 Convection Enhances Mixing in the Southern Ocean Sohail, Taimoor Gayen, Bishakhdatta Hogg, Andy application/pdf http://hdl.handle.net/1885/163982 https://doi.org/10.1029/2018GL077711 https://openresearch-repository.anu.edu.au/bitstream/1885/163982/4/Sohail_et_al-2017-Geophysical_Research_Letters.pdf.jpg en_AU eng American Geophysical Union 0094-8276 http://hdl.handle.net/1885/163982 doi:10.1029/2018GL077711 https://openresearch-repository.anu.edu.au/bitstream/1885/163982/4/Sohail_et_al-2017-Geophysical_Research_Letters.pdf.jpg ©2018. American Geophysical Union Geophysical Research Letters Journal article ftanucanberra https://doi.org/10.1029/2018GL077711 2023-12-15T09:39:16Z Mixing efficiency is a measure of the energy lost to mixing compared to that lost to viscous dissipation. In a turbulent stratified fluid the mixing efficiency is often assumed constant at ???? = 0.2, whereas with convection it takes values closer to 1. The value of mixing efficiency when both stratified shear flow and buoyancy-driven convection are active remains uncertain. We use a series of numerical simulations to determine the mixing efficiency in an idealized Southern Ocean model. The model is energetically closed and fully resolves convection and turbulence such that mixing efficiency can be diagnosed. Mixing efficiency decreases with increasing wind stress but is enhanced by turbulent convection and by large thermal gradients in regions with a strongly stratified thermocline. Using scaling theory and the model results, we predict an overall mixing efficiency for the Southern Ocean that is significantly greater than 0.2 while emphasizing that mixing efficiency is not constant. Article in Journal/Newspaper Southern Ocean Australian National University: ANU Digital Collections Southern Ocean Geophysical Research Letters 45 9 4198 4207 |
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Open Polar |
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Australian National University: ANU Digital Collections |
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ftanucanberra |
language |
English |
description |
Mixing efficiency is a measure of the energy lost to mixing compared to that lost to viscous dissipation. In a turbulent stratified fluid the mixing efficiency is often assumed constant at ???? = 0.2, whereas with convection it takes values closer to 1. The value of mixing efficiency when both stratified shear flow and buoyancy-driven convection are active remains uncertain. We use a series of numerical simulations to determine the mixing efficiency in an idealized Southern Ocean model. The model is energetically closed and fully resolves convection and turbulence such that mixing efficiency can be diagnosed. Mixing efficiency decreases with increasing wind stress but is enhanced by turbulent convection and by large thermal gradients in regions with a strongly stratified thermocline. Using scaling theory and the model results, we predict an overall mixing efficiency for the Southern Ocean that is significantly greater than 0.2 while emphasizing that mixing efficiency is not constant. |
format |
Article in Journal/Newspaper |
author |
Sohail, Taimoor Gayen, Bishakhdatta Hogg, Andy |
spellingShingle |
Sohail, Taimoor Gayen, Bishakhdatta Hogg, Andy Convection Enhances Mixing in the Southern Ocean |
author_facet |
Sohail, Taimoor Gayen, Bishakhdatta Hogg, Andy |
author_sort |
Sohail, Taimoor |
title |
Convection Enhances Mixing in the Southern Ocean |
title_short |
Convection Enhances Mixing in the Southern Ocean |
title_full |
Convection Enhances Mixing in the Southern Ocean |
title_fullStr |
Convection Enhances Mixing in the Southern Ocean |
title_full_unstemmed |
Convection Enhances Mixing in the Southern Ocean |
title_sort |
convection enhances mixing in the southern ocean |
publisher |
American Geophysical Union |
url |
http://hdl.handle.net/1885/163982 https://doi.org/10.1029/2018GL077711 https://openresearch-repository.anu.edu.au/bitstream/1885/163982/4/Sohail_et_al-2017-Geophysical_Research_Letters.pdf.jpg |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Geophysical Research Letters |
op_relation |
0094-8276 http://hdl.handle.net/1885/163982 doi:10.1029/2018GL077711 https://openresearch-repository.anu.edu.au/bitstream/1885/163982/4/Sohail_et_al-2017-Geophysical_Research_Letters.pdf.jpg |
op_rights |
©2018. American Geophysical Union |
op_doi |
https://doi.org/10.1029/2018GL077711 |
container_title |
Geophysical Research Letters |
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45 |
container_issue |
9 |
container_start_page |
4198 |
op_container_end_page |
4207 |
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1788065635697164288 |