Decadal freshening of the Antarctic Bottom Water exported from the Weddell Sea

International audience Recent decadal changes in Southern Hemisphere climate have driven strong responses from the cryo- sphere. Concurrently, there has been a marked freshening of the shelf and bottom waters across a wide sector of the Southern Ocean, hypothesized to be caused by accelerated glacia...

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Bibliographic Details
Published in:Journal of Climate
Main Authors: Jullion, Loïc, Naveira Garabato, Alberto C., Meredith, Michael P., Holland, Paul, H., Courtois, Peggy, King, Brian A.
Other Authors: Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Nathional Oceanography Centre, University of Southampton, British Antarctic Survey (BAS), Natural Environment Research Council (NERC)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2013
Subjects:
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean
Atmosphere
Antarc*
Antarctic
Antarctic Peninsula
Antarctica
Ice Shelves
Sea ice
Southern Ocean
Weddell Sea
West Antarctica
Online Access:https://hal.science/hal-01255767
https://hal.science/hal-01255767/document
https://hal.science/hal-01255767/file/larsen_jclim_submitted.pdf
https://doi.org/10.1175/JCLI-D-12-00765.1
Description
Summary:International audience Recent decadal changes in Southern Hemisphere climate have driven strong responses from the cryo- sphere. Concurrently, there has been a marked freshening of the shelf and bottom waters across a wide sector of the Southern Ocean, hypothesized to be caused by accelerated glacial melt in response to a greater flux of warm waters from the Antarctic Circumpolar Current onto the shelves of West Antarctica. However, the circumpolar pattern of changes has been incomplete: no decadal freshening in the deep layers of the Atlantic sector has been observed. In this study, the authors document a significant freshening of the Antarctic Bottom Water exported from the Weddell Sea, which is the source for the abyssal layer of the Atlantic overturning circulation, and trace its possible origin to atmospheric-forced changes in the ice shelves and sea ice on the eastern flank of the Antarctic Peninsula that include an anthropogenic component. These findings suggest that the expansive and relatively cool Weddell gyre does not insulate the bottom water formation regions in the Atlantic sector from the ongoing changes in climatic forcing over the Antarctic region.

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