Equatorial Walker streamfunction Ψ in longitude–pressure space. We show the zonally overturning circulation patterns for the Baseline (left), Steep Uplift (center), and Plateau (right) simulations. The Baseline case is characterized by broad smoothly varying overturning spanning much of the longitudinal domain. In the Steep Uplift configuration, the circulation breaks into multiple vertically stacked cells with strong longitudinal modulation, consistent with vigorous stationary-wave activity and enhanced three-dimensional mixing. The Plateau case lies between these extremes, maintaining a primary central overturning structure while developing superimposed secondary cells.