Accelerated freshening of Antarctic Bottom Water over the last decade in the Southern Indian Ocean
© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Science Advances 3 (2017): e1601426, doi:10.1126/sciadv.1601426. Southern Ocean abyssal waters, in contact with the atmosphere at their formation si...
Published in: | Science Advances |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
American Association for the Advancement of Science
2017
|
Subjects: | |
Online Access: | https://hdl.handle.net/1912/8717 |
id |
ftwhoas:oai:darchive.mblwhoilibrary.org:1912/8717 |
---|---|
record_format |
openpolar |
spelling |
ftwhoas:oai:darchive.mblwhoilibrary.org:1912/8717 2023-05-15T13:48:30+02:00 Accelerated freshening of Antarctic Bottom Water over the last decade in the Southern Indian Ocean Menezes, Viviane V. Macdonald, Alison M. Schatzman, Courtney 2017-01-25 https://hdl.handle.net/1912/8717 en_US eng American Association for the Advancement of Science https://doi.org/10.1126/sciadv.1601426 Science Advances 3 (2017): e1601426 https://hdl.handle.net/1912/8717 doi:10.1126/sciadv.1601426 Attribution-NonCommercial 4.0 International http://creativecommons.org/licenses/by-nc/4.0/ CC-BY-NC Science Advances 3 (2017): e1601426 doi:10.1126/sciadv.1601426 Salinity AABW Changes Water masses T-S properties Iceberg Calving Antartica Abyss Climate change Article 2017 ftwhoas https://doi.org/10.1126/sciadv.1601426 2022-05-28T22:59:50Z © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Science Advances 3 (2017): e1601426, doi:10.1126/sciadv.1601426. Southern Ocean abyssal waters, in contact with the atmosphere at their formation sites around Antarctica, not only bring signals of a changing climate with them as they move around the globe but also contribute to that change through heat uptake and sea level rise. A repeat hydrographic line in the Indian sector of the Southern Ocean, occupied three times in the last two decades (1994, 2007, and, most recently, 2016), reveals that Antarctic Bottom Water (AABW) continues to become fresher (0.004 ± 0.001 kg/g decade−1), warmer (0.06° ± 0.01°C decade−1), and less dense (0.011 ± 0.002 kg/m3 decade−1). The most recent observations in the Australian-Antarctic Basin show a particularly striking acceleration in AABW freshening between 2007 and 2016 (0.008 ± 0.001 kg/g decade−1) compared to the 0.002 ± 0.001 kg/g decade−1 seen between 1994 and 2007. Freshening is, in part, responsible for an overall shift of the mean temperature-salinity curve toward lower densities. The marked freshening may be linked to an abrupt iceberg-glacier collision and calving event that occurred in 2010 on the George V/Adélie Land Coast, the main source region of bottom waters for the Australian-Antarctic Basin. Because AABW is a key component of the global overturning circulation, the persistent decrease in bottom water density and the associated increase in steric height that result from continued warming and freshening have important consequences beyond the Southern Indian Ocean. The 2016 I08S cruise and the analysis and science performed at sea, as well as the individual principal investigators were funded through multiple National Oceanic and Atmospheric Administration (NOAA) and NSF grants including NSF grant OCE-1437015. The research for this article was mainly completed at sea. For land-based work, V.V.M. relied on her ... Article in Journal/Newspaper Antarc* Antarctic Antarctica antartic* Iceberg* Southern Ocean Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) Antarctic Australian Antarctic Basin ENVELOPE(120.000,120.000,-60.000,-60.000) Australian-Antarctic Basin ENVELOPE(134.115,134.115,-58.800,-58.800) Iceberg Glacier ENVELOPE(-92.134,-92.134,79.517,79.517) Indian Southern Ocean Science Advances 3 1 e1601426 |
institution |
Open Polar |
collection |
Woods Hole Scientific Community: WHOAS (Woods Hole Open Access Server) |
op_collection_id |
ftwhoas |
language |
English |
topic |
Salinity AABW Changes Water masses T-S properties Iceberg Calving Antartica Abyss Climate change |
spellingShingle |
Salinity AABW Changes Water masses T-S properties Iceberg Calving Antartica Abyss Climate change Menezes, Viviane V. Macdonald, Alison M. Schatzman, Courtney Accelerated freshening of Antarctic Bottom Water over the last decade in the Southern Indian Ocean |
topic_facet |
Salinity AABW Changes Water masses T-S properties Iceberg Calving Antartica Abyss Climate change |
description |
© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Science Advances 3 (2017): e1601426, doi:10.1126/sciadv.1601426. Southern Ocean abyssal waters, in contact with the atmosphere at their formation sites around Antarctica, not only bring signals of a changing climate with them as they move around the globe but also contribute to that change through heat uptake and sea level rise. A repeat hydrographic line in the Indian sector of the Southern Ocean, occupied three times in the last two decades (1994, 2007, and, most recently, 2016), reveals that Antarctic Bottom Water (AABW) continues to become fresher (0.004 ± 0.001 kg/g decade−1), warmer (0.06° ± 0.01°C decade−1), and less dense (0.011 ± 0.002 kg/m3 decade−1). The most recent observations in the Australian-Antarctic Basin show a particularly striking acceleration in AABW freshening between 2007 and 2016 (0.008 ± 0.001 kg/g decade−1) compared to the 0.002 ± 0.001 kg/g decade−1 seen between 1994 and 2007. Freshening is, in part, responsible for an overall shift of the mean temperature-salinity curve toward lower densities. The marked freshening may be linked to an abrupt iceberg-glacier collision and calving event that occurred in 2010 on the George V/Adélie Land Coast, the main source region of bottom waters for the Australian-Antarctic Basin. Because AABW is a key component of the global overturning circulation, the persistent decrease in bottom water density and the associated increase in steric height that result from continued warming and freshening have important consequences beyond the Southern Indian Ocean. The 2016 I08S cruise and the analysis and science performed at sea, as well as the individual principal investigators were funded through multiple National Oceanic and Atmospheric Administration (NOAA) and NSF grants including NSF grant OCE-1437015. The research for this article was mainly completed at sea. For land-based work, V.V.M. relied on her ... |
format |
Article in Journal/Newspaper |
author |
Menezes, Viviane V. Macdonald, Alison M. Schatzman, Courtney |
author_facet |
Menezes, Viviane V. Macdonald, Alison M. Schatzman, Courtney |
author_sort |
Menezes, Viviane V. |
title |
Accelerated freshening of Antarctic Bottom Water over the last decade in the Southern Indian Ocean |
title_short |
Accelerated freshening of Antarctic Bottom Water over the last decade in the Southern Indian Ocean |
title_full |
Accelerated freshening of Antarctic Bottom Water over the last decade in the Southern Indian Ocean |
title_fullStr |
Accelerated freshening of Antarctic Bottom Water over the last decade in the Southern Indian Ocean |
title_full_unstemmed |
Accelerated freshening of Antarctic Bottom Water over the last decade in the Southern Indian Ocean |
title_sort |
accelerated freshening of antarctic bottom water over the last decade in the southern indian ocean |
publisher |
American Association for the Advancement of Science |
publishDate |
2017 |
url |
https://hdl.handle.net/1912/8717 |
long_lat |
ENVELOPE(120.000,120.000,-60.000,-60.000) ENVELOPE(134.115,134.115,-58.800,-58.800) ENVELOPE(-92.134,-92.134,79.517,79.517) |
geographic |
Antarctic Australian Antarctic Basin Australian-Antarctic Basin Iceberg Glacier Indian Southern Ocean |
geographic_facet |
Antarctic Australian Antarctic Basin Australian-Antarctic Basin Iceberg Glacier Indian Southern Ocean |
genre |
Antarc* Antarctic Antarctica antartic* Iceberg* Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica antartic* Iceberg* Southern Ocean |
op_source |
Science Advances 3 (2017): e1601426 doi:10.1126/sciadv.1601426 |
op_relation |
https://doi.org/10.1126/sciadv.1601426 Science Advances 3 (2017): e1601426 https://hdl.handle.net/1912/8717 doi:10.1126/sciadv.1601426 |
op_rights |
Attribution-NonCommercial 4.0 International http://creativecommons.org/licenses/by-nc/4.0/ |
op_rightsnorm |
CC-BY-NC |
op_doi |
https://doi.org/10.1126/sciadv.1601426 |
container_title |
Science Advances |
container_volume |
3 |
container_issue |
1 |
container_start_page |
e1601426 |
_version_ |
1766249340751314944 |