Because eddy-topography interactions (topographic stress) are difficult to resolve by numerical models, a parameterization has been proposed by Holloway (1992) based on the statistical mechanical equilibria tendencies (Neptune effect). A vertically integrated numerical model is used to study the influence of Neptune effect upon the tide- and wind-induced residual circulation of the Gulf of California. The model is forced at the mouth of the gulf by the tides and at the sea surface by the wind. It is found that the parameterization induces mean currents in areas where the residuals produced by tides and winds are small. Tide- and wind-induced residuals are large along the mainland coast and from the archipelago to the north, where the Neptune effect parameterization is less important. Observations give some support to this parameterization. ¿ 1998 American Geophysical Union