Details about the orange, red, and purple boxes in Fig. 2. The orange box shows an interval with ${\text{SO}}_2{}^{+}$ cyclotron waves. The panels within the box show, from top to bottom: the MFA parallel magnetic field strength; the two MFA perpendicular magnetic field components; the power spectrum (with the cyclotron frequency of the sulfur-bearing ions shown by a black vertical line and the grey shaded area the interval over which the total spectral power is integrated); and a hodogram of the two MFA perpendicular magnetic field components. The red box shows the same for an interval with predominantly ${\text{SO}}_3{}^{+}$ cyclotron waves. The purple box shows the mirror mode waves in Io’s wake region.