| Summary: | Surface buoyancy fluxes in the Southern and North Atlantic Oceans are presumed to disproportionately influence the ocean's residual global overturning circulation (GOC) with respect to those in the Indoâ€Pacific. Here, this assumption is challenged through an assessment of global buoyancy transport in the Community Earth System Model 1.0, which reveals that the steady state GOC is equally constrained by surface buoyancy flux everywhere. Further, an unacknowledged aspect of the GOC is demonstrated: it transports buoyancy from where it is gained at the surface, predominately in the Indoâ€Pacific, to where it is lost, predominately in the Atlantic and Southern Oceans. This global buoyancy transport requires zonal structure in the GOC, linking the Atlantic and Indoâ€Pacific within the Southern Ocean, asymmetry and interbasin coupling absent from many conceptual descriptions of overturning dynamics. These results compel a more nuanced appreciation for an Indoâ€Pacific influence in GOC evolution. © 2018. American Geophysical Union. Received 5 SEP 2018. Accepted 29 OCT 2018. Accepted article online 1 NOV 2018. Published online 28 NOV 2018. We thank Igor Kamenkovich, an anonymous reviewer, and the Editor for constructive suggestions, and Cecilia Bitz, Jess Adkins, Frank Bryan, and Lynne Talley for helpful discussions. This work was funded by the National Oceanic and Atmospheric Administration (NOAA) CGC Fellowship (E. R. N.) and by the National Science Foundation (NSF) grant OCEâ€1235488 (A. F. T.). Output from the simulation used is available for download at http://www.cesm.ucar.edu/experiments/cesm1.0/. Published - Newsom_et_al-2018-Geophysical_Research_Letters.pdf Supplemental Material - downloadSupplement_doi=10.1029_2F2018GL080350_file=grl58236-sup-0001-Supplementary.pdf
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