Wilcox Solar Observatory (WSO) photospheric field maps, CR 1908–1913. Black denotes strong negative‐polarity flux (Br ≤ −8 G); white denotes strong positive‐polarity flux (Br ≥ 8 G), while intermediate shades indicate fields in the range −8 G < Br < 8 G. Because the magnetograph measurements were made around central meridian rather than at the limb, the actual times of observation for the magnetic fields in Fig. 6 lag (precede) those for the east (west) limb streamers in Fig. 5a (Fig. 5b) by approximately 7 days.