Spiraling pathways of global deep waters to the surface of the Southern Ocean

• Published in: Nature Communications
• Main Authors: Tamsitt, Veronica, Drake, Henri F. Princeton Univ., NJ, Massachusetts Inst. of Technology , Cambridge, MA, Woods Hole Oceanographic Inst. Joint Program in Oceanography, Cambridge, MA, Morrison, Adele K. Princeton Univ., NJ, Australian National Univ., Canberra, ACT, Talley, Lynne D. Univ. of California, San Diego, CA . Scripps Inst. of Oceanography, Dufour, Carolina O. Princeton Univ., NJ, Gray, Alison R. Princeton Univ., NJ, Griffies, Stephen M. Geophysical Fluid Dynamics Lab., Princeton, NJ, Mazloff, Matthew R. Univ. of California, San Diego, CA . Scripps Inst. of Oceanography, Sarmiento, Jorge L. Princeton Univ., NJ, Wang, Jinbo California Inst. of Technology , La Canada Flintridge, CA . Jet Propulsion Lab., Weijer, Wilbert Los Alamos National Lab. , Los Alamos, NM
• Language: unknown
• Published: 2023
• Subjects: 58 GEOSCIENCES; Antarctic; Southern Ocean; The Antarctic; Antarc*; Ice Shelves
• Online Access: http://www.osti.gov/servlets/purl/1463556; https://www.osti.gov/biblio/1463556; https://doi.org/10.1038/s41467-017-00197-0

Upwelling of global deep waters to the sea surface in the Southern Ocean closes the global overturning circulation and is fundamentally important for oceanic uptake of carbon and heat, nutrient resupply for sustaining oceanic biological production, and the melt rate of ice shelves. However, the exact pathways and role of topography in Southern Ocean upwelling remain largely unknown. Here in this paper we show detailed upwelling pathways in three dimensions, using hydrographic observations and particle tracking in high-resolution models. The analysis reveals that the northern-sourced deep waters enter the Antarctic Circumpolar Current via southward flow along the boundaries of the three ocean basins, before spiraling southeastward and upward through the Antarctic Circumpolar Current. Upwelling is greatly enhanced at five major topographic features, associated with vigorous mesoscale eddy activity. Deep water reaches the upper ocean predominantly south of the Antarctic Circumpolar Current, with a spatially nonuniform distribution. The timescale for half of the deep water to upwell from 30° S to the mixed layer is ~60–90 years.