Illustration of the relative magnetic flux imbalance in the major voids and the QS. For each of the six major voids, we calculated the relative flux imbalance as defined in Eq. (2). The respective imbalances are then plotted as a single value within the contour of the respective void (see also Fig. 1 and Table 1). The + and − signs overplotted on or just beside the voids indicate the net magnetic polarity within each void. Likewise, the QS region is coloured corresponding to the (negligible) flux imbalance of the QS. See Sect. 3.4