Role of Residual Overturning for the Sensitivity of Southern Ocean Isopycnal Slopes to Changes in Wind Forcing
The Antarctic Circumpolar Current plays a central role in the ventilation of heat and carbon in the global ocean. In particular, the isopycnal slopes determine where each water mass outcrops and thus how the ocean interacts with the atmosphere. The region-integrated isopycnal slopes have been sugges...
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ftmit:oai:dspace.mit.edu:1721.1/124644 2023-06-11T04:06:36+02:00 Role of Residual Overturning for the Sensitivity of Southern Ocean Isopycnal Slopes to Changes in Wind Forcing Youngs, Madeleine Flierl, Glenn R. Ferrarix, Raffaele Joint Program in Oceanography Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences 2020-04-08T18:26:54Z application/pdf https://hdl.handle.net/1721.1/124644 en eng American Meteorological Society 10.1175/JPO-D-19-0072.1 Journal of Physical Oceanography 1520-0485 https://hdl.handle.net/1721.1/124644 Youngs, Madeleine K. et.al., "Role of Residual Overturning for the Sensitivity of Southern Ocean Isopycnal Slopes to Changes in Wind Forcing." Journal of Physical Oceanography 49, 11 (October 2019): 2867–81 doi. 10.1175/JPO-D-19-0072.1 ©2019 Authors 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. American Meteorological Society Article http://purl.org/eprint/type/JournalArticle 2020 ftmit https://doi.org/10.1175/JPO-D-19-0072.1 2023-05-29T08:52:06Z The Antarctic Circumpolar Current plays a central role in the ventilation of heat and carbon in the global ocean. In particular, the isopycnal slopes determine where each water mass outcrops and thus how the ocean interacts with the atmosphere. The region-integrated isopycnal slopes have been suggested to be eddy saturated, that is, stay relatively constant as the wind forcing changes, but whether or not the flow is saturated in realistic present day and future parameter regimes is unknown. This study analyzes an idealized two-layer quasigeostrophic channel model forced by a wind stress and a residual overturning generated by a mass flux across the interface between the two layers, with and without a blocking ridge. The sign and strength of the residual overturning set which way the isopycnal slopes change with the wind forcing, leading to an increase in slope with an increase in wind forcing for a positive overturning and a decrease in slope for a negative overturning, following the usual conventions; this behavior is caused by the dominant standing meander weakening as the wind stress weakens causing the isopycnal slopes to become more sensitive to changes in the wind stress and converge with the slopes of a flat-bottomed simulation. Eddy saturation only appears once the wind forcing passes a critical level. These results show that theories for saturation must have both topography and residual overturning in order to be complete and provide a framework for understanding how the isopycnal slopes in the Southern Ocean may change in response to future changes in wind forcing. ©2019 American Meteorological Society. MKY and RF acknowledge support through NSF Awards (OCE-1536515) and (AGS-1835576). MKY acknowledges funding from NDSEG. GRF was supported by (NSF OCE-1459702) Article in Journal/Newspaper Antarc* Antarctic Southern Ocean DSpace@MIT (Massachusetts Institute of Technology) Antarctic Southern Ocean The Antarctic Journal of Physical Oceanography 49 11 2867 2881 |
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Open Polar |
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DSpace@MIT (Massachusetts Institute of Technology) |
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ftmit |
language |
English |
description |
The Antarctic Circumpolar Current plays a central role in the ventilation of heat and carbon in the global ocean. In particular, the isopycnal slopes determine where each water mass outcrops and thus how the ocean interacts with the atmosphere. The region-integrated isopycnal slopes have been suggested to be eddy saturated, that is, stay relatively constant as the wind forcing changes, but whether or not the flow is saturated in realistic present day and future parameter regimes is unknown. This study analyzes an idealized two-layer quasigeostrophic channel model forced by a wind stress and a residual overturning generated by a mass flux across the interface between the two layers, with and without a blocking ridge. The sign and strength of the residual overturning set which way the isopycnal slopes change with the wind forcing, leading to an increase in slope with an increase in wind forcing for a positive overturning and a decrease in slope for a negative overturning, following the usual conventions; this behavior is caused by the dominant standing meander weakening as the wind stress weakens causing the isopycnal slopes to become more sensitive to changes in the wind stress and converge with the slopes of a flat-bottomed simulation. Eddy saturation only appears once the wind forcing passes a critical level. These results show that theories for saturation must have both topography and residual overturning in order to be complete and provide a framework for understanding how the isopycnal slopes in the Southern Ocean may change in response to future changes in wind forcing. ©2019 American Meteorological Society. MKY and RF acknowledge support through NSF Awards (OCE-1536515) and (AGS-1835576). MKY acknowledges funding from NDSEG. GRF was supported by (NSF OCE-1459702) |
author2 |
Joint Program in Oceanography Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
format |
Article in Journal/Newspaper |
author |
Youngs, Madeleine Flierl, Glenn R. Ferrarix, Raffaele |
spellingShingle |
Youngs, Madeleine Flierl, Glenn R. Ferrarix, Raffaele Role of Residual Overturning for the Sensitivity of Southern Ocean Isopycnal Slopes to Changes in Wind Forcing |
author_facet |
Youngs, Madeleine Flierl, Glenn R. Ferrarix, Raffaele |
author_sort |
Youngs, Madeleine |
title |
Role of Residual Overturning for the Sensitivity of Southern Ocean Isopycnal Slopes to Changes in Wind Forcing |
title_short |
Role of Residual Overturning for the Sensitivity of Southern Ocean Isopycnal Slopes to Changes in Wind Forcing |
title_full |
Role of Residual Overturning for the Sensitivity of Southern Ocean Isopycnal Slopes to Changes in Wind Forcing |
title_fullStr |
Role of Residual Overturning for the Sensitivity of Southern Ocean Isopycnal Slopes to Changes in Wind Forcing |
title_full_unstemmed |
Role of Residual Overturning for the Sensitivity of Southern Ocean Isopycnal Slopes to Changes in Wind Forcing |
title_sort |
role of residual overturning for the sensitivity of southern ocean isopycnal slopes to changes in wind forcing |
publisher |
American Meteorological Society |
publishDate |
2020 |
url |
https://hdl.handle.net/1721.1/124644 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
American Meteorological Society |
op_relation |
10.1175/JPO-D-19-0072.1 Journal of Physical Oceanography 1520-0485 https://hdl.handle.net/1721.1/124644 Youngs, Madeleine K. et.al., "Role of Residual Overturning for the Sensitivity of Southern Ocean Isopycnal Slopes to Changes in Wind Forcing." Journal of Physical Oceanography 49, 11 (October 2019): 2867–81 doi. 10.1175/JPO-D-19-0072.1 ©2019 Authors |
op_rights |
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. |
op_doi |
https://doi.org/10.1175/JPO-D-19-0072.1 |
container_title |
Journal of Physical Oceanography |
container_volume |
49 |
container_issue |
11 |
container_start_page |
2867 |
op_container_end_page |
2881 |
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1768378623462473728 |