Relation between filling factor and coronal conductive flux. Top: magnetic filling factor on the photosphere f_* versus backward conductive flux measured in the corona. The half loop length is fixed to l_loop =20 Mm. The red circles and blue diamonds represent the flux measured at T_ave = 10⁶ K and averaged in 10 Mm ≤ s ≤ 15 Mm. The black solid line is the power-law fitting to the blue diamonds. Bottom: same as the top panel but the vertical axis denotes .