ABSTRACT
The Southern Ocean (SO) plays a critical role in the earth’s carbon–climate–biogeochemistry nexus through its mediation of both anthropogenic and natural carbon fluxes as well as the earth’s energy imbalance and nutrient supplies that support 75% of ocean primary production outside the SO. We focus on the coupled nature of the large-scale carbon and climate (heat and wind) fluxes and resulting feedback fluxes. These are needed to understand the past, present, and future role of the SO carbon–climate system in the earth system (ES). We highlight that though these SO-ES links are dominated by large-scale atmosphere and ocean interior fluxes, it is the surface mixed layer and its physics and biogeochemical processes that connect the two and mediate both carbon and carbon–climate feedback fluxes. We suggest that mixed layer dynamics, particularly the interface with the ocean interior, is a significant challenge towards understanding and projecting the evolution of the past and future carbon and climate links of the SO in the ES.
