= Solution
Southern Ocean westerly <wind stress> drives northward surface <Ekman transport> in the Southern Hemisphere. Its divergence and the circumpolar geometry allow deep water to rise towards the surface along tilted <isopycnals>, providing an important return route for the deep branch of the <Atlantic meridional overturning circulation>. Surface <heat fluxes> and freshwater fluxes then transform the upwelled water before it enters shallower return pathways. The winds supply mechanical <energy>; the overturning cannot be represented entirely by a local northern <density> difference. <Eddy-induced overturning> opposes part of the wind-driven contribution, so the net <water-mass transformation> and transport need not increase in direct proportion to the <wind stress>.https://www.awi.de/en/science/climate-sciences/physical-oceanography/main-research-focus/southern-ocean-overturning-circulation.html[Alfred Wegener Institute, Southern Ocean overturning circulation: wind-driven upwelling and its opposition by mesoscale eddies]{ref}
Back to article page
