Short-circuiting of the oceanic overturning circulation in the Antarctic Circumpolar Current
The oceanic overturning circulation has a central role in the Earth's climate system and in biogeochemical cycling as it transports heat, carbon and nutrients around the globe and regulates their storage in the deep ocean. Mixing processes in the Antarctic Circumpolar Current are key to this ci...
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ftsouthampton:oai:eprints.soton.ac.uk:42476 2023-08-27T04:04:21+02:00 Short-circuiting of the oceanic overturning circulation in the Antarctic Circumpolar Current Naveira Garabato, Alberto C. Stevens, David P. Watson, Andrew J. Roether, Watson Roether, Wolfgang 2007 https://eprints.soton.ac.uk/42476/ unknown Naveira Garabato, Alberto C., Stevens, David P., Watson, Andrew J., Roether, Watson and Roether, Wolfgang (2007) Short-circuiting of the oceanic overturning circulation in the Antarctic Circumpolar Current. Nature, 447 (7141), 194-197. (doi:10.1038/nature05832 <http://dx.doi.org/10.1038/nature05832>). Article PeerReviewed 2007 ftsouthampton https://doi.org/10.1038/nature05832 2023-08-03T22:19:05Z The oceanic overturning circulation has a central role in the Earth's climate system and in biogeochemical cycling as it transports heat, carbon and nutrients around the globe and regulates their storage in the deep ocean. Mixing processes in the Antarctic Circumpolar Current are key to this circulation, because they control the rate at which water sinking at high latitudes returns to the surface in the Southern Ocean. Yet estimates of the rates of these processes and of the upwelling that they induce are poorly constrained by observations. Here we take advantage of a natural tracer-release experiment—an injection of mantle helium from hydrothermal vents into the Circumpolar Current near Drake Passage9—to measure the rates of mixing and upwelling in the current's intermediate layers over a sector that spans nearly one-tenth of its circumpolar path. Dispersion of the tracer reveals rapid upwelling along density surfaces and intense mixing across density surfaces, both occurring at rates that are an order of magnitude greater than rates implicit in models of the average Southern Ocean overturning. These findings support the view that deep-water pathways along and across density surfaces intensify and intertwine as the Antarctic Circumpolar Current flows over complex ocean-floor topography, giving rise to a short circuit of the overturning circulation in these regions. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean University of Southampton: e-Prints Soton Antarctic Southern Ocean The Antarctic Nature 447 7141 194 197 |
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University of Southampton: e-Prints Soton |
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ftsouthampton |
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The oceanic overturning circulation has a central role in the Earth's climate system and in biogeochemical cycling as it transports heat, carbon and nutrients around the globe and regulates their storage in the deep ocean. Mixing processes in the Antarctic Circumpolar Current are key to this circulation, because they control the rate at which water sinking at high latitudes returns to the surface in the Southern Ocean. Yet estimates of the rates of these processes and of the upwelling that they induce are poorly constrained by observations. Here we take advantage of a natural tracer-release experiment—an injection of mantle helium from hydrothermal vents into the Circumpolar Current near Drake Passage9—to measure the rates of mixing and upwelling in the current's intermediate layers over a sector that spans nearly one-tenth of its circumpolar path. Dispersion of the tracer reveals rapid upwelling along density surfaces and intense mixing across density surfaces, both occurring at rates that are an order of magnitude greater than rates implicit in models of the average Southern Ocean overturning. These findings support the view that deep-water pathways along and across density surfaces intensify and intertwine as the Antarctic Circumpolar Current flows over complex ocean-floor topography, giving rise to a short circuit of the overturning circulation in these regions. |
format |
Article in Journal/Newspaper |
author |
Naveira Garabato, Alberto C. Stevens, David P. Watson, Andrew J. Roether, Watson Roether, Wolfgang |
spellingShingle |
Naveira Garabato, Alberto C. Stevens, David P. Watson, Andrew J. Roether, Watson Roether, Wolfgang Short-circuiting of the oceanic overturning circulation in the Antarctic Circumpolar Current |
author_facet |
Naveira Garabato, Alberto C. Stevens, David P. Watson, Andrew J. Roether, Watson Roether, Wolfgang |
author_sort |
Naveira Garabato, Alberto C. |
title |
Short-circuiting of the oceanic overturning circulation in the Antarctic Circumpolar Current |
title_short |
Short-circuiting of the oceanic overturning circulation in the Antarctic Circumpolar Current |
title_full |
Short-circuiting of the oceanic overturning circulation in the Antarctic Circumpolar Current |
title_fullStr |
Short-circuiting of the oceanic overturning circulation in the Antarctic Circumpolar Current |
title_full_unstemmed |
Short-circuiting of the oceanic overturning circulation in the Antarctic Circumpolar Current |
title_sort |
short-circuiting of the oceanic overturning circulation in the antarctic circumpolar current |
publishDate |
2007 |
url |
https://eprints.soton.ac.uk/42476/ |
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 |
Naveira Garabato, Alberto C., Stevens, David P., Watson, Andrew J., Roether, Watson and Roether, Wolfgang (2007) Short-circuiting of the oceanic overturning circulation in the Antarctic Circumpolar Current. Nature, 447 (7141), 194-197. (doi:10.1038/nature05832 <http://dx.doi.org/10.1038/nature05832>). |
op_doi |
https://doi.org/10.1038/nature05832 |
container_title |
Nature |
container_volume |
447 |
container_issue |
7141 |
container_start_page |
194 |
op_container_end_page |
197 |
_version_ |
1775350790399983616 |