Shoaling of abyssal ventilation in the Eastern Indian Sector of the Southern Ocean

• Published in: Communications Earth & Environment
• Main Authors: Shimada Keishi, Kitade Yujiro, Aoki Shigeru, Mizobata Kohei, Cheng Lingqiao, Takahashi Kunio, Makabe Ryosuke, Kanda Jota, Odate Tsuneo
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Nature 2022
• Subjects: Climate change; Physical oceanography; 南極底層水の昇温・低塩化に伴う深層大循環の変貌予測に関する基礎研究; Basic research on the prediction of changing for the Deep Global Circulation related with warming and freshening of Antarctic Bottom Water; 東南極トッテン棚氷へ暖水を運ぶ巨大な定在海洋渦の成因と循環流量の変動要因の解明; Elucidation of the formation mechanisms of the large standing oceanic eddy and the factors controlling eddy circulation contributing to warm water transport to the Totten Ice Shelf in East Antarctica; Antarctic; Australian Antarctic Basin; Australian-Antarctic Basin; East Antarctica; Indian; Southern Ocean; The Antarctic; Antarc*; Antarctica; Ice Shelf; Totten Ice Shelf
• Online Access: https://oacis.repo.nii.ac.jp/?action=repository_uri&item_id=2457; http://id.nii.ac.jp/1342/00002395/

Antarctic Bottom Water formation, which ventilates the abyssal layers of the Southern Ocean, is an integral component of the global ocean meridional overturning circulation. Considering evident freshening and density decreases in the source waters, widespread warming in the Southern Ocean suggests a weakening in the Antarctic Bottom Water supply. We demonstrate that the weakening is robust based on water mass warming in the deep and abyssal layers of the Australian-Antarctic Basin, which remained after removing the southward shift effect of the Southern Antarctic Circumpolar Current Front. Moreover, a decrease in apparent oxygen utilisation and reduced warming in the intermediate density layer below Circumpolar Deep Water extended further from the Australian-Antarctic Basin to the South Australian Basin. We suggest that a concurrent weakening in the densest portion and strengthening in the less dense portion shape the multi-basin change in the meridional overturning circulation that originates from the Southern Ocean. この論文のプレスリリースはこちら : http://id.nii.ac.jp/1342/00002394/