Rates and mechanisms of turbulent dissipation and mixing in the Southern Ocean: Results from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES)
The spatial distribution of turbulent dissipation rates and internal wavefield characteristics is analyzed across two contrasting regimes of the Antarctic Circumpolar Current (ACC), using microstructure and finestructure data collected as part of the Diapycnal and Isopycnal Mixing Experiment in the...
Published in: | Journal of Geophysical Research: Oceans |
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2013
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ftunswworks:oai:unsworks.library.unsw.edu.au:1959.4/53712 2023-05-15T13:55:10+02:00 Rates and mechanisms of turbulent dissipation and mixing in the Southern Ocean: Results from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) Sheen, K Brearley, J Garabato, A Smeed, D Waterman, Stephanie Ledwell, J Meredith, M St Laurent, L Thurnherr, A Toole, J Watson, A 2013 application/pdf http://hdl.handle.net/1959.4/53712 https://unsworks.unsw.edu.au/bitstreams/57582dcb-cdf8-4043-976c-606834ae90b6/download https://doi.org/10.1002/jgrc.20217 EN eng http://hdl.handle.net/1959.4/53712 https://unsworks.unsw.edu.au/bitstreams/57582dcb-cdf8-4043-976c-606834ae90b6/download http://dx.doi.org/10.1002/jgrc.20217 open access https://purl.org/coar/access_right/c_abf2 CC BY-NC-ND 3.0 https://creativecommons.org/licenses/by-nc-nd/3.0/au/ free_to_read Copyright (2013) American Geophysical Union. Published version available at: http://dx.doi.org/10.1002/jgrc.20217 CC-BY-NC-ND urn:ISSN:2169-9291 Journal of Geophysical Research: Oceans, 118, 6, 2774-2792 journal article http://purl.org/coar/resource_type/c_6501 2013 ftunswworks https://doi.org/10.1002/jgrc.20217 2022-08-09T07:43:55Z The spatial distribution of turbulent dissipation rates and internal wavefield characteristics is analyzed across two contrasting regimes of the Antarctic Circumpolar Current (ACC), using microstructure and finestructure data collected as part of the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES). Mid-depth turbulent dissipation rates are found to increase from O(1x10-10Wkg-1) in the Southeast Pacific to O(1x10-9Wkg-1) in the Scotia Sea, typically reaching 3x10-9Wkg-1 within a kilometer of the seabed. Enhanced levels of turbulent mixing are associated with strong near-bottom flows, rough topography, and regions where the internal wavefield is found to have enhanced energy, a less-inertial frequency content and a dominance of upward propagating energy. These results strongly suggest that bottom-generated internal waves play a major role in determining the spatial distribution of turbulent dissipation in the ACC. The energy flux associated with the bottom internal wave generation process is calculated using wave radiation theory, and found to vary between 0.8 mW m(-2) in the Southeast Pacific and 14 mW m(-2) in the Scotia Sea. Typically, 10%-30% of this energy is found to dissipate within 1 km of the seabed. Comparison between turbulent dissipation rates inferred from finestructure parameterizations and microstructure-derived estimates suggests a significant departure from wave-wave interaction physics in the near-field of wave generation sites. Article in Journal/Newspaper Antarc* Antarctic Scotia Sea Southern Ocean UNSW Sydney (The University of New South Wales): UNSWorks Antarctic Pacific Scotia Sea Southern Ocean The Antarctic Journal of Geophysical Research: Oceans 118 6 2774 2792 |
institution |
Open Polar |
collection |
UNSW Sydney (The University of New South Wales): UNSWorks |
op_collection_id |
ftunswworks |
language |
English |
description |
The spatial distribution of turbulent dissipation rates and internal wavefield characteristics is analyzed across two contrasting regimes of the Antarctic Circumpolar Current (ACC), using microstructure and finestructure data collected as part of the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES). Mid-depth turbulent dissipation rates are found to increase from O(1x10-10Wkg-1) in the Southeast Pacific to O(1x10-9Wkg-1) in the Scotia Sea, typically reaching 3x10-9Wkg-1 within a kilometer of the seabed. Enhanced levels of turbulent mixing are associated with strong near-bottom flows, rough topography, and regions where the internal wavefield is found to have enhanced energy, a less-inertial frequency content and a dominance of upward propagating energy. These results strongly suggest that bottom-generated internal waves play a major role in determining the spatial distribution of turbulent dissipation in the ACC. The energy flux associated with the bottom internal wave generation process is calculated using wave radiation theory, and found to vary between 0.8 mW m(-2) in the Southeast Pacific and 14 mW m(-2) in the Scotia Sea. Typically, 10%-30% of this energy is found to dissipate within 1 km of the seabed. Comparison between turbulent dissipation rates inferred from finestructure parameterizations and microstructure-derived estimates suggests a significant departure from wave-wave interaction physics in the near-field of wave generation sites. |
format |
Article in Journal/Newspaper |
author |
Sheen, K Brearley, J Garabato, A Smeed, D Waterman, Stephanie Ledwell, J Meredith, M St Laurent, L Thurnherr, A Toole, J Watson, A |
spellingShingle |
Sheen, K Brearley, J Garabato, A Smeed, D Waterman, Stephanie Ledwell, J Meredith, M St Laurent, L Thurnherr, A Toole, J Watson, A Rates and mechanisms of turbulent dissipation and mixing in the Southern Ocean: Results from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) |
author_facet |
Sheen, K Brearley, J Garabato, A Smeed, D Waterman, Stephanie Ledwell, J Meredith, M St Laurent, L Thurnherr, A Toole, J Watson, A |
author_sort |
Sheen, K |
title |
Rates and mechanisms of turbulent dissipation and mixing in the Southern Ocean: Results from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) |
title_short |
Rates and mechanisms of turbulent dissipation and mixing in the Southern Ocean: Results from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) |
title_full |
Rates and mechanisms of turbulent dissipation and mixing in the Southern Ocean: Results from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) |
title_fullStr |
Rates and mechanisms of turbulent dissipation and mixing in the Southern Ocean: Results from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) |
title_full_unstemmed |
Rates and mechanisms of turbulent dissipation and mixing in the Southern Ocean: Results from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) |
title_sort |
rates and mechanisms of turbulent dissipation and mixing in the southern ocean: results from the diapycnal and isopycnal mixing experiment in the southern ocean (dimes) |
publishDate |
2013 |
url |
http://hdl.handle.net/1959.4/53712 https://unsworks.unsw.edu.au/bitstreams/57582dcb-cdf8-4043-976c-606834ae90b6/download https://doi.org/10.1002/jgrc.20217 |
geographic |
Antarctic Pacific Scotia Sea Southern Ocean The Antarctic |
geographic_facet |
Antarctic Pacific Scotia Sea Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Scotia Sea Southern Ocean |
genre_facet |
Antarc* Antarctic Scotia Sea Southern Ocean |
op_source |
urn:ISSN:2169-9291 Journal of Geophysical Research: Oceans, 118, 6, 2774-2792 |
op_relation |
http://hdl.handle.net/1959.4/53712 https://unsworks.unsw.edu.au/bitstreams/57582dcb-cdf8-4043-976c-606834ae90b6/download http://dx.doi.org/10.1002/jgrc.20217 |
op_rights |
open access https://purl.org/coar/access_right/c_abf2 CC BY-NC-ND 3.0 https://creativecommons.org/licenses/by-nc-nd/3.0/au/ free_to_read Copyright (2013) American Geophysical Union. Published version available at: http://dx.doi.org/10.1002/jgrc.20217 |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.1002/jgrc.20217 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
118 |
container_issue |
6 |
container_start_page |
2774 |
op_container_end_page |
2792 |
_version_ |
1766261448260976640 |