HCl (upper left) and H₂O (lower left) VMR vertical profiles, as in Fig. 2, for an occultation made during the aphelion season (L_s = 115°) at (46°N, 97°W). The spectra used in the retrieval (orders 173–175) over three tangent heights are shown at the right, as in Fig. 1. HCl and H₂O are constrained to below 15 km. These observations made outside the perihelion dust season are considered robust and may be indicative of local dust events or possible outgassing.