Plasma source history and M³ comparison geometry. (a) Representative phase-dependent THEMIS-ARTEMIS ion flux used to scale the incident implanted H source in the model. Lunar phase is shown relative to the magnetotail center. (b) Low- and midlatitude M³ comparison targets plotted by lunar phase and local time. These sampling windows define the model–data comparison bins and show why the comparison must preserve phase, local time, and latitude rather than use a single averaged diurnal curve.