FIG. 6.

(Left): Limb radiances at 463 cm⁻¹ measured by MCS (top) and dust mass mixing ratio retrieved from MCS measurements (bottom), exhibiting a detached dust layer at 50–60 km altitude over Tharsis (Heavens et al., 2015). The density-scaled optical depth (d_zτ) is related to the optical depth at 0.67 μm (dτ) by d_zτ = −dτ/ρ, where ρ is atmospheric density in units of kg/m³. (Right): Mesoscale model simulation showing density-scaled dust opacity in a so-called rocket dust storm, in which dust can be lifted to altitudes 30–40 km within a few hours (Spiga et al., 2013). MCS, Mars Climate Sounder.