Potential and limitation of remote sensing observations to monitor super coarse particles of ambient aerosol

The potential presence of super coarse desert dust aerosol particles  with volume radii larger than 15 microns in the atmosphere has recently become one of hot topics intensively discussed in the modeling and observation community. Such large particles may represent an essential part of aerosol mass in the atmosphere and while their contribution to atmospheric radiation is rather moderate. Therefore, the characterization of super coarse aerosols is very challenging while they are responsible for sizable overall contributions in aerosol effects environment and climate dynamics. Indeed, AERONET network, that arguably can be considered as the most comprehensive source of information about ambient columnar aerosol properties does not consider aerosol particles with radius larger  than 15 microns. In contrast, most chemical transport models do consider super course particles and a number of in situ campaigns have reported the presence of such particles. This presentation describes efforts to test and evaluate the capabilities and limitations of detecting the super coarse dust particles from AERONET like measurements. It also considers possibilities to detect such particles using other remote sensing methods including lidar active observation and measurements in IR spectral range. Several modifications of the retrieval approaches that allow for optimizing remote sensing of super coarse ambient aerosol are proposed and discussed.