Disentangling wind- and buoyancy-driven changes in Pacific circulation and regional sea level during 1960–2014

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 circulation changes and explains 54% of regional sea-level trend, while buoyancy forcing contributes 19% of circulation changes but 46% of regional sea-level trend. Circulation changes diagnosed from Barotropic Stream Function match estimations from 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 poleward flanks of subtropical gyres. Buoyancy forcing partly compensates for wind-driven changes in the North Pacific and exerts a weaker, 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 under climate changes.