Magnetic field components (top: radial field, middle: meridional field, bottom: azimuthal field) averaged over the latitude interval −60° to 90° from each ZDI map. Each stripe represents the average field from one ZDI map, extended over the time axis to help the visualisation. The stripes are organised as function of time, according to their observational epoch, running from top to bottom. Dark colours represent negative polarities, bright colours positive ones; in all figures a linear colour table with minimum of −300 G and maximum of 300 G has been used.