Recent Freshening, Warming, and Contraction of the Antarctic Bottom Water in the Indian Sector of the Southern Ocean
High saline and cold Antarctic Bottom Water (AABW) forms around the continental margin of Antarctica that ventilates into the global ocean. To study the recent changes in AABW, we have analyzed the in situ observations collected from Indian Ocean expeditions to the Southern Ocean during 2010, 2011,...
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ftdoajarticles:oai:doaj.org/article:571e9394805f40249447aa4b04d5c46a 2023-05-15T13:47:39+02:00 Recent Freshening, Warming, and Contraction of the Antarctic Bottom Water in the Indian Sector of the Southern Ocean N Anilkumar Babula Jena Jenson V. George Sabu P Kshitija S M Ravichandran 2021-11-01T00:00:00Z https://doi.org/10.3389/fmars.2021.730630 https://doaj.org/article/571e9394805f40249447aa4b04d5c46a EN eng Frontiers Media S.A. https://www.frontiersin.org/articles/10.3389/fmars.2021.730630/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2021.730630 https://doaj.org/article/571e9394805f40249447aa4b04d5c46a Frontiers in Marine Science, Vol 8 (2021) Antarctic Bottom Water (AABW) freshening contraction Circumpolar Deep Water (CDW) sea ice Science Q General. Including nature conservation geographical distribution QH1-199.5 article 2021 ftdoajarticles https://doi.org/10.3389/fmars.2021.730630 2022-12-31T07:22:03Z High saline and cold Antarctic Bottom Water (AABW) forms around the continental margin of Antarctica that ventilates into the global ocean. To study the recent changes in AABW, we have analyzed the in situ observations collected from Indian Ocean expeditions to the Southern Ocean during 2010, 2011, 2017, 2018, and 2020. A comprehensive analysis of these observations indicated recent freshening, warming, and contraction in the layer thickness of the AABW. Even though the AABW depicted inter-annual variability, it changed to moderately fresher and lighter water mass at the end of the recent decade. The characteristics of AABW exhibited a contraction in its layer thickness (∼50–120 m) during recent years. The water mass showed its freshening (∼0.002) and warming (∼0.04°C) tendency from 2018 to 2020. The recent warming (∼0.3°C) of Circumpolar Deep Water (CDW) near the Prydz Bay suggests enhanced melting of ice shelves. It is hypothesized that the combined influences of onshore intrusion of warm CDW, upper ocean warming, sea ice decline, wind forcing, polynya, and calving events possibly caused the freshening and reduction in the thickness of AABW. The continued changes in the ocean-atmospheric environmental conditions and the subsequent changes in the bottom water characteristics likely influence the global climate, overturning circulation, and the biogeochemical cycle. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Shelves Prydz Bay Sea ice Southern Ocean Directory of Open Access Journals: DOAJ Articles Antarctic Indian Prydz Bay Southern Ocean The Antarctic Frontiers in Marine Science 8 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Antarctic Bottom Water (AABW) freshening contraction Circumpolar Deep Water (CDW) sea ice Science Q General. Including nature conservation geographical distribution QH1-199.5 |
spellingShingle |
Antarctic Bottom Water (AABW) freshening contraction Circumpolar Deep Water (CDW) sea ice Science Q General. Including nature conservation geographical distribution QH1-199.5 N Anilkumar Babula Jena Jenson V. George Sabu P Kshitija S M Ravichandran Recent Freshening, Warming, and Contraction of the Antarctic Bottom Water in the Indian Sector of the Southern Ocean |
topic_facet |
Antarctic Bottom Water (AABW) freshening contraction Circumpolar Deep Water (CDW) sea ice Science Q General. Including nature conservation geographical distribution QH1-199.5 |
description |
High saline and cold Antarctic Bottom Water (AABW) forms around the continental margin of Antarctica that ventilates into the global ocean. To study the recent changes in AABW, we have analyzed the in situ observations collected from Indian Ocean expeditions to the Southern Ocean during 2010, 2011, 2017, 2018, and 2020. A comprehensive analysis of these observations indicated recent freshening, warming, and contraction in the layer thickness of the AABW. Even though the AABW depicted inter-annual variability, it changed to moderately fresher and lighter water mass at the end of the recent decade. The characteristics of AABW exhibited a contraction in its layer thickness (∼50–120 m) during recent years. The water mass showed its freshening (∼0.002) and warming (∼0.04°C) tendency from 2018 to 2020. The recent warming (∼0.3°C) of Circumpolar Deep Water (CDW) near the Prydz Bay suggests enhanced melting of ice shelves. It is hypothesized that the combined influences of onshore intrusion of warm CDW, upper ocean warming, sea ice decline, wind forcing, polynya, and calving events possibly caused the freshening and reduction in the thickness of AABW. The continued changes in the ocean-atmospheric environmental conditions and the subsequent changes in the bottom water characteristics likely influence the global climate, overturning circulation, and the biogeochemical cycle. |
format |
Article in Journal/Newspaper |
author |
N Anilkumar Babula Jena Jenson V. George Sabu P Kshitija S M Ravichandran |
author_facet |
N Anilkumar Babula Jena Jenson V. George Sabu P Kshitija S M Ravichandran |
author_sort |
N Anilkumar |
title |
Recent Freshening, Warming, and Contraction of the Antarctic Bottom Water in the Indian Sector of the Southern Ocean |
title_short |
Recent Freshening, Warming, and Contraction of the Antarctic Bottom Water in the Indian Sector of the Southern Ocean |
title_full |
Recent Freshening, Warming, and Contraction of the Antarctic Bottom Water in the Indian Sector of the Southern Ocean |
title_fullStr |
Recent Freshening, Warming, and Contraction of the Antarctic Bottom Water in the Indian Sector of the Southern Ocean |
title_full_unstemmed |
Recent Freshening, Warming, and Contraction of the Antarctic Bottom Water in the Indian Sector of the Southern Ocean |
title_sort |
recent freshening, warming, and contraction of the antarctic bottom water in the indian sector of the southern ocean |
publisher |
Frontiers Media S.A. |
publishDate |
2021 |
url |
https://doi.org/10.3389/fmars.2021.730630 https://doaj.org/article/571e9394805f40249447aa4b04d5c46a |
geographic |
Antarctic Indian Prydz Bay Southern Ocean The Antarctic |
geographic_facet |
Antarctic Indian Prydz Bay Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Shelves Prydz Bay Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Ice Shelves Prydz Bay Sea ice Southern Ocean |
op_source |
Frontiers in Marine Science, Vol 8 (2021) |
op_relation |
https://www.frontiersin.org/articles/10.3389/fmars.2021.730630/full https://doaj.org/toc/2296-7745 2296-7745 doi:10.3389/fmars.2021.730630 https://doaj.org/article/571e9394805f40249447aa4b04d5c46a |
op_doi |
https://doi.org/10.3389/fmars.2021.730630 |
container_title |
Frontiers in Marine Science |
container_volume |
8 |
_version_ |
1766247598888321024 |