The intense, efficient transfer of organic carbon from the surface to the deep Southern Ocean make it a key component of the global carbon cycle. Observations show that this process isn't always driven by sinking diatom skeletons, which often don't make it past the mid-depth twilight zone, ...
Here we present direct springtime flux measurements from different sectors of the subpolar Southern Ocean, demonstrating that across large areas of the subpolar twilight zone, carbon is efficiently transferred to depth, albeit not by diatoms. Rather, opal is retained near the surface ocean, ...