Remotely induced warming of Antarctic Bottom Water in the eastern Weddell gyre
Four repeat hydrographic sections across the eastern Weddell gyre at 30E reveal a warming (by ~0.1C) and lightening (by ~0.02-0.03 kg m-3) of the Antarctic Bottom Water (AABW) entering the gyre from the Indian sector of the Southern Ocean between the mid-1990s and late 2000s.Historical hydrographic...
Published in: | Geophysical Research Letters |
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Main Authors: | , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley-Blackwell Publishing, Inc.
2013
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Subjects: | |
Online Access: | https://doi.org/10.1002/grl.50526 http://ecite.utas.edu.au/84736 |
Summary: | Four repeat hydrographic sections across the eastern Weddell gyre at 30E reveal a warming (by ~0.1C) and lightening (by ~0.02-0.03 kg m-3) of the Antarctic Bottom Water (AABW) entering the gyre from the Indian sector of the Southern Ocean between the mid-1990s and late 2000s.Historical hydrographic and altimetric measurements in the region suggest that the most likely explanation for the change is increased entrainment of warmer mid-depth Circumpolar Deep Water by cascading shelf water plumes close to Cape Darnley, where the Indian-sourced AABW entering the Weddell gyre from the east is ventilated. This change in entrainment is associated with a concurrent southward shift of the Antarctic Circumpolar Currents (ACC) southern boundary in the region. This mechanism of AABW warming may affect wherever the ACC flows close to Antarctica. |
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