Disentangling Wind‐ and Buoyancy‐Driven Changes in Pacific Barotropic Circulation and Regional Sea Level During 1960–2014

Abstract Relative roles of wind stress and buoyancy forcing in shaping Pacific circulation and sea level remain unclear. Using large‐ensemble simulations from Community Earth System Model version 2, we disentangle the contributions of wind and buoyancy fluxes during 1960–2014. Wind stress accounts for 81% of barotropic circulation changes and explains 54% of regional sea‐level trend, while buoyancy forcing contributes 19% of barotropic circulation changes but 46% of regional sea‐level trend. Circulation changes diagnosed from the barotropic stream function match estimations from the Sverdrup stream function, underscoring the reliability of wind‐driven frameworks. Wind stress drives ocean heat redistribution through meridional transport and subduction, inducing sea‐level rise along the poleward flanks of subtropical gyres. Buoyancy forcing partially offsets wind‐driven changes in the North Pacific, while exerting a weaker but synergistic influence in the South Pacific. These findings highlight the dominant yet regionally modulated role of wind stress in shaping Pacific circulation and sea level.