Investigation and Modeling of Ice Clouds Affecting Earth-Space Communication Systems

A model for ice clouds oriented to provide a useful tool for the accurate assessment of the impact of ice particles on Earth-space communications systems is presented. The model, developed starting from the data collected by the CloudSat LEO satellite, allows to synthesize vertical profiles of the ice water content from the sole knowledge of the whole integrated ice water content, which, in turn, can be typically obtained from numerical weather prediction models or as a remote sensing product of Earth observation satellites. Moreover, the base of ice clouds is investigated and modeled, separately for mid- and high-altitude clouds, mostly consisting only of ice particles, and for low-level clouds, typically composed by both ice and liquid water. In addition, the impact of ice clouds on Earth-space optical links is preliminary investigated. Results, obtained for two sites, indicate that the attenuation due to ice is not negligible at optical wavelengths, as it can be in the order of tens of decibels on zenithal paths. The present model is intended to be integrated into a broader simulator of weather disturbances affecting electromagnetic wave propagation, conceived to support the design and performance assessment of Earth-space communication systems (EHF range or optical wavelengths).