A set of numerical simulations of the tropical Pacific Ocean during the 1985–94 decade is used to investigate the effects of haline stratification on the low-frequency equilibrium of the Coupled Ocean–Atmosphere Response Experiment region. The simulated sea surface salinity structure is found to be quite sensitive to the freshwater forcing and to the other fluxes. Despite this sensitivity, several robust features are found in the model. Sensitivity experiments illustrate the important role of the haline stratification in the western Pacific. This stratification is the result of a balance between precipitations and entrainment of subsurface saltier water. It inhibits the downward penetration of turbulent kinetic energy. This results notably in a trapping of the westerly wind burst momentum in the surface layer, giving rise to strong fresh equatorial jets. The model is able to produce a barrier layer between 5°N and 10°S in the western Pacific and under the intertropical convergence zone (as in the... Abstract A set of numerical simulations of the tropical Pacific Ocean during the 1985–94 decade is used to investigate the effects of haline stratification on the low-frequency equilibrium of the Coupled Ocean–Atmosphere Response Experiment region. The simulated sea surface salinity structure is found to be quite sensitive to the freshwater forcing and to the other fluxes. Despite this sensitivity, several robust features are found in the model. Sensitivity experiments illustrate the important role of the haline stratification in the western Pacific. This stratification is the result of a balance between precipitations and entrainment of subsurface saltier water. It inhibits the downward penetration of turbulent kinetic energy. This results notably in a trapping of the westerly wind burst momentum in the surface layer, giving rise to strong fresh equatorial jets. The model is able to produce a barrier layer between 5°N and 10°S in the western Pacific and under the intertropical convergence zone (as in the...