Time series of the sunspot number and positive dipole axis latitude since the beginning of sunspot cycle 23. The solid grey lines have a monthly, or CR, cadence. The dashed red lines show the 13-month smoothed version of each time series. The start times of sunspot cycles 23, 24, and 25 are identified with dotted vertical lines. Horizontal bars indicate when the reversal of the dipole component is halted for several solar rotations. The magenta bars labelled (a), (b), and (c) are discussed in Sect. 3.