Top: Distribution of SPMI power calculated with the Saur et al. (2013) (blue), Lanza (2013) (green), and Paul & Strugarek (2026) (orange) models for all field lines in Figure 2 whose footpoints lie within 5° of the brightening. The field lines are generated from the minute cadence of the comet’s trajectory. The single-field-line values from Section 2.2 are indicated by vertical dashed lines. Bottom: Propagation time of hypothetical Alfvén waves for each magnetic field line as a function of the associated SPMI power. The red points correspond to the powers labeled with vertical dashed lines in the upper panel.