Field line helicity for different orientations of a BMR, labeled by tilt angle in degrees. In each case, the left panel shows Br on ﹩r={r}_{0}﹩ (white positive, black negative) with magnetic field lines colored by ﹩{ \mathcal A }| {B}_{r}| ﹩ (using the larger of the two endpoint ﹩| {B}_{r}| ﹩ values). The right panel shows the corresponding distribution of ﹩{ \mathcal A }| {B}_{r}| ﹩ on ﹩r={r}_{0}﹩, with Br = ±1 G contours in black. Units of ﹩{ \mathcal A }| {B}_{r}| ﹩ are ﹩{10}^{22}\,{\mathrm{Mx}}^{2}\,{\mathrm{cm}}^{-2}﹩. The dipolar background field is always positive to the north and negative to the south.