Time series of integrated meridional flows for pole-on configuration (first panel) and edge-on configuration (second panel) for U10 reconstruction. Two types of uncertainties are shown (see text): a lower limit (red) and an upper limit (black). Third panel: S-index from Sacramento Peak Observatory between 1985 and 2011 (the solid line corresponds to a smoothingover 100 days). Last panel: monthly spot number (stars), superposed on a smoothed time series as a solid line.