Longitudinal structures of SPICAM temperature observations for (a) South-Low-Clear, (b) South-Mid-Clear, (c) South-Low-Dusty, and (d) North-Low-Dusty. Panels (e)–(h) show the corresponding structures from sampled PCM data. Dots indicate data points and shaded regions represent ±1σ uncertainties of the composite fits. Panels (i) to (l) show the amplitudes and ±1σ uncertainties of waves 1–4, normalized by the zonal mean for the four cases in (a)–(d). For clarity, the SPICAM and sampled PCM profiles are vertically offset by +1 km and −1 km, respectively. The SPICAM amplitudes use dashed semi-transparent lines; PCM amplitudes use solid, opaque lines. Panels (m)–(p) show the corresponding phases and ±1σ uncertainties, defined as the longitude of the first eastward peak from 0^◦ for each harmonic component. The temperature structures in the first two rows are vertically offset by [−100, −30, 30, 120, 200, 290] K for 80–130 km altitudes, except for the North-Low-Dusty case, which uses [−100, −30, 70, 210, 320, 450] K.