East-west separation, δx (top); north-south separation, δy (middle); and tilt angle, γ (bottom) of the polarities as a function of latitude, λ, at the emergence time (left) and two days later (right). The sign of the north-south separation and the tilt angle of active regions in the southern hemisphere have been adjusted, i.e. in the southern (northern) hemisphere a negative (positive) δy and a negative (positive) γ is consistent with Joy’s law (black curve, Wang & Sheeley 1991). The size of the circle is proportional to the maximum flux of the active region. The thick black points with error bars show latitudinal averages between 0 and 15° (sin λ = 0.26) and 15° to 40° (sin λ = 0.64) in the northern hemisphere, and the equivalent in the southern hemisphere. The dashed lines are the mean values.