CESM1-simualted climatology (contours, in 0.1 m/s) and changes (color, in 0.1 m/s, relative the control-run climatology) averaged over years 131–150 of October-March zonal-mean meridional wind from the (a) 1% CO2 run and (b) FixedIce run. Panel c is the panel a minus b difference. Significant wind changes in (a, b) or differences in (c) at the 5% level are marked by the black dots. The contours in (c) are for the control-run climatology of the meridional wind. The changes around the 1st CO2 doubling (for years 61–80) have similar patterns with smaller magnitudes.