Spatial and temporal patterns of small-scale mixing in Drake Passage
Temperature and salinity profiles obtained with expendable CTD probes throughout Drake Passage between February 2002 and July 2005 are analyzed to estimate turbulent diapycnal eddy diffusivities to a depth of 1000 m. Diffusivity values are inferred from density/temperature inversions and internal wa...
Published in: | Journal of Physical Oceanography |
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ftuniveastangl:oai:ueaeprints.uea.ac.uk:25175 2023-05-15T16:02:25+02:00 Spatial and temporal patterns of small-scale mixing in Drake Passage Thompson, Andrew F. Gille, Sarah T. MacKinnon, J. A. Sprintall, Janet 2007-03 https://ueaeprints.uea.ac.uk/id/eprint/25175/ https://doi.org/10.1175/JPO3021.1 unknown Thompson, Andrew F., Gille, Sarah T., MacKinnon, J. A. and Sprintall, Janet (2007) Spatial and temporal patterns of small-scale mixing in Drake Passage. Journal of Physical Oceanography, 37 (3). pp. 572-592. doi:10.1175/JPO3021.1 Article PeerReviewed 2007 ftuniveastangl https://doi.org/10.1175/JPO3021.1 2023-02-02T23:30:57Z Temperature and salinity profiles obtained with expendable CTD probes throughout Drake Passage between February 2002 and July 2005 are analyzed to estimate turbulent diapycnal eddy diffusivities to a depth of 1000 m. Diffusivity values are inferred from density/temperature inversions and internal wave vertical strain. Both methods reveal the same pattern of spatial variability across Drake Passage; diffusivity estimates from inversions exceed those from vertical strain by a factor of 3 over most of Drake Passage. The Polar Front (PF) separates two dynamically different regions. Strong thermohaline intrusions characterize profiles obtained north of the PF. South of the PF, stratification is determined largely by salinity, and temperature is typically unstably stratified between 100- and 600-m depth. In the upper 400 m, turbulent diapycnal diffusivities are O(10−3 m2 s−1) north of the PF but decrease to O(10−4 m2 s−1) or smaller south of the PF. Below 400 m diffusivities typically exceed 10−4 m2 s−1. Diffusivities decay weakly with depth north of the PF, whereas diffusivities increase with depth and peak near the local temperature maximum south of the PF. The meridional pattern in near-surface mixing corresponds to local maxima and minima of both wind stress and wind stress variance. Near-surface diffusivities are also found to be larger during winter months north of the PF. Wind-driven near-inertial waves, strong mesoscale eddy activity, and double-diffusive convection are suggested as possible factors contributing to observed mixing patterns. Article in Journal/Newspaper Drake Passage University of East Anglia: UEA Digital Repository Drake Passage Journal of Physical Oceanography 37 3 572 592 |
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Open Polar |
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University of East Anglia: UEA Digital Repository |
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ftuniveastangl |
language |
unknown |
description |
Temperature and salinity profiles obtained with expendable CTD probes throughout Drake Passage between February 2002 and July 2005 are analyzed to estimate turbulent diapycnal eddy diffusivities to a depth of 1000 m. Diffusivity values are inferred from density/temperature inversions and internal wave vertical strain. Both methods reveal the same pattern of spatial variability across Drake Passage; diffusivity estimates from inversions exceed those from vertical strain by a factor of 3 over most of Drake Passage. The Polar Front (PF) separates two dynamically different regions. Strong thermohaline intrusions characterize profiles obtained north of the PF. South of the PF, stratification is determined largely by salinity, and temperature is typically unstably stratified between 100- and 600-m depth. In the upper 400 m, turbulent diapycnal diffusivities are O(10−3 m2 s−1) north of the PF but decrease to O(10−4 m2 s−1) or smaller south of the PF. Below 400 m diffusivities typically exceed 10−4 m2 s−1. Diffusivities decay weakly with depth north of the PF, whereas diffusivities increase with depth and peak near the local temperature maximum south of the PF. The meridional pattern in near-surface mixing corresponds to local maxima and minima of both wind stress and wind stress variance. Near-surface diffusivities are also found to be larger during winter months north of the PF. Wind-driven near-inertial waves, strong mesoscale eddy activity, and double-diffusive convection are suggested as possible factors contributing to observed mixing patterns. |
format |
Article in Journal/Newspaper |
author |
Thompson, Andrew F. Gille, Sarah T. MacKinnon, J. A. Sprintall, Janet |
spellingShingle |
Thompson, Andrew F. Gille, Sarah T. MacKinnon, J. A. Sprintall, Janet Spatial and temporal patterns of small-scale mixing in Drake Passage |
author_facet |
Thompson, Andrew F. Gille, Sarah T. MacKinnon, J. A. Sprintall, Janet |
author_sort |
Thompson, Andrew F. |
title |
Spatial and temporal patterns of small-scale mixing in Drake Passage |
title_short |
Spatial and temporal patterns of small-scale mixing in Drake Passage |
title_full |
Spatial and temporal patterns of small-scale mixing in Drake Passage |
title_fullStr |
Spatial and temporal patterns of small-scale mixing in Drake Passage |
title_full_unstemmed |
Spatial and temporal patterns of small-scale mixing in Drake Passage |
title_sort |
spatial and temporal patterns of small-scale mixing in drake passage |
publishDate |
2007 |
url |
https://ueaeprints.uea.ac.uk/id/eprint/25175/ https://doi.org/10.1175/JPO3021.1 |
geographic |
Drake Passage |
geographic_facet |
Drake Passage |
genre |
Drake Passage |
genre_facet |
Drake Passage |
op_relation |
Thompson, Andrew F., Gille, Sarah T., MacKinnon, J. A. and Sprintall, Janet (2007) Spatial and temporal patterns of small-scale mixing in Drake Passage. Journal of Physical Oceanography, 37 (3). pp. 572-592. doi:10.1175/JPO3021.1 |
op_doi |
https://doi.org/10.1175/JPO3021.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
37 |
container_issue |
3 |
container_start_page |
572 |
op_container_end_page |
592 |
_version_ |
1766398011912486912 |