Scattering of Hydrometeors

A profound understanding of the scattering properties of hydrometeors is key to extract information from passive and active MW observations. The natural variety of hydrometeor properties also leads to the complexity of how they interact with electromagnetic radiation. The challenge of calculating hydrometeor scattering properties is not only the scattering method itself but starts with an accurate characterization of the hydrometeors themselves. The number and sophistication of those hydrometeor models has rapidly grown during recent years, as has the number of publicly available databases of their scattering properties. This development opens up new possibilities to improve the quality of retrievals but also raises new questions on how to best coordinate the scattering community efforts in the future. While sufficient confidence exists for liquid hydrometeor scattering properties, frozen hydrometeors remain challenging and the questions of how to best model their physical properties and how to derive average properties representative for global applications are still under discussion.