Warm surface waters increase Antarctic ice shelf melt and delay dense water formation

Melting ice shelves around Antarctica control the massive input of freshwater into the ocean and play an intricate role in global heat redistribution. The Amery Ice Shelf regulates wintertime sea-ice growth and dense shelf water formation. We investigated the role of warm Antarctic Surface Water in...

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Bibliographic Details
Published in:Communications Earth & Environment
Main Authors: Aoki, Shigeru, Takahashi, Tomoki, Yamazaki, Kaihe, Hirano, Daisuke, Ono, Kazuya, Kusahara, Kazuya, Tamura, Takeshi, Williams, Guy D.
Format: Article in Journal/Newspaper
Language:English
Published: Springer Nature
Subjects:
452
Online Access:http://hdl.handle.net/2115/86487
https://doi.org/10.1038/s43247-022-00456-z
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Summary:Melting ice shelves around Antarctica control the massive input of freshwater into the ocean and play an intricate role in global heat redistribution. The Amery Ice Shelf regulates wintertime sea-ice growth and dense shelf water formation. We investigated the role of warm Antarctic Surface Water in ice shelf melting and its impact on dense shelf water. Here we show that the coastal ocean in summer 2016/17 was almost sea-ice free, leading to higher surface water temperatures. The glacial meltwater fraction in surface water was the highest on record, hypothesised to be attributable to anomalous ice shelf melting. The excess heat and freshwater in early 2017 delayed the seasonal evolution of dense shelf water. Focused on ice shelf melting at depth, the importance and impacts of warming surface waters has been overlooked. In a warming climate, increased surface water heating will reduce coastal sea-ice production and potentially Antarctic Bottom Water formation. Excessively warm and fresh surface water along the Amery Ice Shelf, Antarctica, in 2017 led to more ice melt and delayed dense water formation, according to analyses of in situ observations.