Mass distribution over the whole 22-year solar cycle at four given points along the Earth’s orbit (compare to Sterken et al. 2013). Upper left panel: upstream of the Sun. Upper right panel: at an angle of 90° between upstream and downstream position. Lower left panel: downstream of the Sun, inside the spot of maximum focussing. Lower right panel: 18° away from the downstream direction, outside the strongly localised spot of maximum focussing. The variations seen in each panel reflectthe changes due to the focussing/defocussing effects of the IMF throughout the solar cycle.