Mesoscale coupled climate model wind stress sensitivity experiments. One of the biggest uncertainties about the Southern Ocean is how the competing effects of wind stress and buoyancy forcing affect the tracer, velocity and eddy characteristics there. In order to explicitly examine these effects, we will conduct experiments in which a fixed wind stress anomaly pattern (brown dotted line in figure) with varying amplitudes is added to the internally calculated wind stress over the Southern Ocean according to the numerical technique described in Delworth and Zeng (2008). Zonal mean of the zonal wind stress simulated in the CM2.1 experiments conducted for the study of Delworth and Zeng (2008)In these experiments, the model ocean “feels” altered Southern Hemisphere winds, while the atmosphere “has no direct knowledge of these altered winds” and is only impacted through changes to the ocean that the wind stress anomalies induce. The applied anomaly is derived from SresA1B simulations with GFDL-CM2.1 conducted as part of the IPCC-AR4. Our sensitivity simulations will be run in GFDL’s new CM4 Earth System Model at 0.25° ocean resolution (10-25 km) with a full biogeochemistry module. We will then assess changes in momentum, tracers, stratification, heat and carbon fluxes, etc.