Relationship between BMR magnetic flux and sunspot area. (a) Amount of magnetic flux in newly emerged BMRs, Φ_BMR, as a function of the area of the enclosed sunspots, A_BMR,S, as indicated by the empirical relationship between Φ_BMR and A_BMR,S presented in this study (black solid line, Eq. (8)) and the constraints on Φ_BMR reported by SH (blue, Eq. (10)) and LCC (red, Eq. (13)). For the estimate of Φ_BMR based on the SH result, the lower and upper bounds, corresponding to k = 1 and k = 2, are given. The dashed line follows the amount of magnetic flux in newly emerged BMRs contained in the embedded sunspots, Φ_BMR,S (Eq. (7)). (b) Corresponding plot of . To an approximation, is directly proportional to the fraction of the area of each BMR occupied by their sunspots, , indicated on the right axis (Eq. (9)) (see Sects. 2.2 and 2.3 for details).