Scientific Challenges for Lidar-Based Dust and Ice Cloud Characterization on Mars

The scientific goals of the MiLi project (‘Miniaturized Lidar for MARS Advanced Atmospheric Research’) are addressed to the characterization of Martian aerosols (dust and ice clouds) in vertical resolution. These studies will represent a key factor to investigate their climatic implications on Mars. First, a terrestrial version of the MiLi system is designed to be an elastic lidar with a [2β + 1δ] configuration, which represents an extended performance of the first lidar on Mars, the Phoenix mission, by incorporating, in particular, depolarization capabilities. Hence, the primary scientific MiLi challenges for Mars atmospheric exploration are three-fold: (1) detection of high-altitude dust and ice cloud layers (>30 km height; plausible dust-cloud interactions); (2) for the first time, estimation of their depolarization ratio; and (3) discrimination between dust and ice clouds. Earth-based representative atmospheric scenarios are simulated by considering different optical and microphysical properties of dust and ice cloud particles on Mars, being discussed in terms of expected lidar signal levels.