Enhanced upwelling of Antarctic Bottom Water by topographic interaction of water mass interfaces ...

• Main Authors: Baker, Lois, Mashayek, Ali, Naveira Garabato, Alberto
• Format: Conference Object
• Language: unknown
• Published: GFZ German Research Centre for Geosciences 2023
• Subjects: Antarctic; Southern Ocean; The Antarctic; Weddell Sea; Drake Passage; Pacific; Weddell; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.57757/iugg23-1573; https://gfzpublic.gfz-potsdam.de/pubman/item/item_5018033

<!--!introduction!--> The lower cell of the meridional overturning circulation (MOC) is sourced by dense Antarctic Bottom Water (AABW), which forms and sinks around Antarctica and subsequently fills the abyssal ocean. For the MOC to ‘overturn’, these dense waters must upwell through mixing with lighter waters above. Here, we investigate the processes underpinning such mixing, and the resulting water mass transformation, using an observationally forced, high-resolution numerical model of the Drake Passage in the Southern Ocean. In the Drake Passage, the mixing of dense AABW formed in the Weddell Sea with lighter deep waters transported from the Pacific Ocean by the Antarctic Circumpolar Current is catalysed by energetic flows impinging on rough topography. We find that multiple topographic interaction processes act to facilitate mixing of the two water masses, ultimately resulting in upwelling of waters with neutral density greater 28.19 kg m -3 , and downwelling of the lighter waters above. In ... : The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) ...