Zonal mean zonal winds (m s⁻¹, shading), and the zonal mean streamfunction (contours; solid are for clockwise circulation, kg s⁻¹). The contour spacing for the stream-function is max(ψ)/10, for simulations forced by T_Obs with depths of 1, 3, 10, and 30 bar (panels a-d, respectively). For the 1 and 3 bar simulations (panels a and b) the winds are multiplied by 4 and 2, respectively, so that all panels share a common colorbar.