How Does Antarctic Bottom Water Cross the Southern Ocean?

• Published in: Geophysical Research Letters
• Main Authors: Solodoch, A, Stewart, AL, Hogg, A McC, Morrison, AK, Kiss, AE, Thompson, AF, Purkey, SG, Cimoli, L
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: eScholarship, University of California 2022
• Subjects: Life Below Water; meridional overturning circulation; Antarctic Bottom Water; ocean circulation; Southern Ocean; Deep Western Boundary Currents; ocean stirring; Meteorology & Atmospheric Sciences; Adelie Land; Antarc*; Antarctic; Prydz Bay; Ross Sea; Sea ice; Weddell Sea
• Online Access: https://escholarship.org/uc/item/4861k9v1; https://escholarship.org/content/qt4861k9v1/qt4861k9v1.pdf; https://doi.org/10.1029/2021gl097211

Antarctic Bottom Water (AABW), which fills the global ocean abyss, is derived from dense water that forms in several distinct Antarctic shelf regions. Previous modeling studies have reached conflicting conclusions regarding export pathways of AABW across the Southern Ocean and the degree to which AABW originating from distinct source regions are blended during their export. This study addresses these questions using passive tracer deployments in a 61-year global high-resolution (0.1°) ocean/sea-ice simulation. Two distinct export “conduits” are identified: Weddell Sea- and Prydz Bay-sourced AABW are blended together and exported mainly to the Atlantic and Indian Oceans, while Ross Sea- and Adelie Land-sourced AABW are exported mainly to the Pacific Ocean. Northward transport of each tracer occurs almost exclusively (>90%) within a single conduit. These findings imply that regional changes in AABW production may impact the three-dimensional structure of the global overturning circulation.