Eddy heat flux in the Southern Ocean: response to variable wind forcing
The authors assess the role of time-dependent eddy variability in the Antarctic Circumpolar Current (ACC) in influencing warming of the Southern Ocean. For this, an eddy-resolving quasigeostrophic model of the wind-driven circulation is used, and the response of circumpolar transport, eddy kinetic e...
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ftsouthampton:oai:eprints.soton.ac.uk:50562 2023-07-30T03:59:26+02:00 Eddy heat flux in the Southern Ocean: response to variable wind forcing Hogg, A.McC. Meredith, M.P. Blundell, J.R. Wilson, C. 2008-02-15 https://eprints.soton.ac.uk/50562/ http://ams.allenpress.com/perlserv/?request=get-document&doi=10.1175%2F2007JCLI1925.1 unknown Hogg, A.McC., Meredith, M.P., Blundell, J.R. and Wilson, C. (2008) Eddy heat flux in the Southern Ocean: response to variable wind forcing. Journal of Climate, 21 (4), 608-620. (doi:10.1175/2007JCLI1925.1 <http://dx.doi.org/10.1175/2007JCLI1925.1>). Article PeerReviewed 2008 ftsouthampton https://doi.org/10.1175/2007JCLI1925.1 2023-07-09T20:54:55Z The authors assess the role of time-dependent eddy variability in the Antarctic Circumpolar Current (ACC) in influencing warming of the Southern Ocean. For this, an eddy-resolving quasigeostrophic model of the wind-driven circulation is used, and the response of circumpolar transport, eddy kinetic energy, and eddy heat transport to changes in winds is quantified. On interannual time scales, the model exhibits the behavior of an “eddy saturated” ocean state, where increases in wind stress do not significantly change the circumpolar transport, but instead enhance the eddy field. This is in accord with previous dynamical arguments, and a recent observational study. The instantaneous response to increased wind stress is to cool temperatures through increased northward Ekman transport of cool water. But, in the longer term, the enhanced eddy state is more efficient at transporting heat, leading to a warming of the ocean. The total eddy heat flux response is greater than the Ekman transport heat flux in this model by a factor of 2, indicating that coarse (non eddy resolving) models may fail to adequately capture the key processes. The authors also test the model response to long-term changes in wind forcing, including steadily increasing circumpolar wind strength over a 30-yr period. The model shows a response in eddy heat flux, and a change in ocean temperature not dissimilar from observed Southern Ocean warming. These findings suggest that eddy heat flux, energized by increasing wind stress, may be a significant contributor to the observed warming of the Southern Ocean. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean University of Southampton: e-Prints Soton Antarctic Southern Ocean The Antarctic Journal of Climate 21 4 608 620 |
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Open Polar |
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University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
unknown |
description |
The authors assess the role of time-dependent eddy variability in the Antarctic Circumpolar Current (ACC) in influencing warming of the Southern Ocean. For this, an eddy-resolving quasigeostrophic model of the wind-driven circulation is used, and the response of circumpolar transport, eddy kinetic energy, and eddy heat transport to changes in winds is quantified. On interannual time scales, the model exhibits the behavior of an “eddy saturated” ocean state, where increases in wind stress do not significantly change the circumpolar transport, but instead enhance the eddy field. This is in accord with previous dynamical arguments, and a recent observational study. The instantaneous response to increased wind stress is to cool temperatures through increased northward Ekman transport of cool water. But, in the longer term, the enhanced eddy state is more efficient at transporting heat, leading to a warming of the ocean. The total eddy heat flux response is greater than the Ekman transport heat flux in this model by a factor of 2, indicating that coarse (non eddy resolving) models may fail to adequately capture the key processes. The authors also test the model response to long-term changes in wind forcing, including steadily increasing circumpolar wind strength over a 30-yr period. The model shows a response in eddy heat flux, and a change in ocean temperature not dissimilar from observed Southern Ocean warming. These findings suggest that eddy heat flux, energized by increasing wind stress, may be a significant contributor to the observed warming of the Southern Ocean. |
format |
Article in Journal/Newspaper |
author |
Hogg, A.McC. Meredith, M.P. Blundell, J.R. Wilson, C. |
spellingShingle |
Hogg, A.McC. Meredith, M.P. Blundell, J.R. Wilson, C. Eddy heat flux in the Southern Ocean: response to variable wind forcing |
author_facet |
Hogg, A.McC. Meredith, M.P. Blundell, J.R. Wilson, C. |
author_sort |
Hogg, A.McC. |
title |
Eddy heat flux in the Southern Ocean: response to variable wind forcing |
title_short |
Eddy heat flux in the Southern Ocean: response to variable wind forcing |
title_full |
Eddy heat flux in the Southern Ocean: response to variable wind forcing |
title_fullStr |
Eddy heat flux in the Southern Ocean: response to variable wind forcing |
title_full_unstemmed |
Eddy heat flux in the Southern Ocean: response to variable wind forcing |
title_sort |
eddy heat flux in the southern ocean: response to variable wind forcing |
publishDate |
2008 |
url |
https://eprints.soton.ac.uk/50562/ http://ams.allenpress.com/perlserv/?request=get-document&doi=10.1175%2F2007JCLI1925.1 |
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_relation |
Hogg, A.McC., Meredith, M.P., Blundell, J.R. and Wilson, C. (2008) Eddy heat flux in the Southern Ocean: response to variable wind forcing. Journal of Climate, 21 (4), 608-620. (doi:10.1175/2007JCLI1925.1 <http://dx.doi.org/10.1175/2007JCLI1925.1>). |
op_doi |
https://doi.org/10.1175/2007JCLI1925.1 |
container_title |
Journal of Climate |
container_volume |
21 |
container_issue |
4 |
container_start_page |
608 |
op_container_end_page |
620 |
_version_ |
1772810250092544000 |