The Southern Ocean mixed layer and its boundary fluxes: fine-scale observational progress and future research priorities.

Interactions between the upper ocean and air-ice-ocean fluxes in the Southern Ocean play a critical role in global climate by impacting the overturning circulation and oceanic heat and carbon uptake. Remote and challenging conditions have led to sparse observational coverage, while ongoing field programmes often fail to collect sufficient information in the right place or at the time-space scales required to constrain the variability occurring in the coupled ocean-atmosphere system. Only within the last 10 years have we been able to directly observe and assess the role of the fine-scale ocean and rapidly evolving atmospheric marine boundary layer on the upper limb of the Southern Ocean's overturning circulation.

Storms drive outgassing of CO in the subpolar Southern Ocean.

The subpolar Southern Ocean is a critical region where CO outgassing influences the global mean air-sea CO flux (F). However, the processes controlling the outgassing remain elusive. We show, using a multi-glider dataset combining F and ocean turbulence, that the air-sea gradient of CO (∆pCO) is modulated by synoptic storm-driven ocean variability (20 µatm, 1-10 days) through two processes.