The Southern Ocean plays a critical role in the global carbon cycle. The dominating current in the region, the Antarctic Circumpolar Current (ACC), circumnavigates the globe and connects all of the major ocean basins. Its overturning circulation brings up the deepwater and subducts thermocline and intermediate waters that are major conduits for the oceanic uptake of heat and anthropogenic carbon (Armour et al., 2016; Ben Bronselaer & Zanna, 2020;Toggweiler & Russell, 2008), contributing over 40% of the ocean carbon uptake (Khatiwala et al., 2009). Despite its importance, there are large uncertainties surrounding components controlling the regional carbon flux. While the state-of-the-art Earth System Models (ESMs) generally reproduce the annual mean carbon flux in the region, its seasonal cycle is often poorly correlated with observations (Jiang et al., 2014;Mongwe et al., 2016).The ACC is filled with mesoscale (approx. 10-100 km) features with meandering jets and vortices (eddies) that play central roles to maintain the stratification and the overturning circulation with global implications (Gnanadesikan, 1999;Johnson & Bryden, 1989;Marshall & Radko, 2003;Marshall & Speer, 2012). This rich mesoscale eddy field is critical for the transport of carbon and nutrients in the region, but the current generation of ESMs cannot resolve these features due to their coarse resolution and the challenge of parameterizing eddies realistically.To study the influence of mesoscale eddies on the carbon cycle in this region, we perform and compare three computational simulations for a sensitivity study using a regional physical and biological model with a 10km horizontal resolution. This modeling study is focused on the Drake Passage region, which is the only section of the ACC bounded by land topography to the north and south and relatively well sampled by ship-based