Seasonal variations in the H₂O longitude-integrated column density (left) and the H₂O₂ longitude-integrated volume mixing ratio (right) during the beginning of southern summer (Ls = 180°–220°) in the case of a clear atmosphere (blue) and during a global dust storm (red). Solid curves: equator; dashed curves: 32S longitude. The black vertical line indicates the solar longitude corresponding to the TEXES observation.