Measurement and parameterization of rainfall microstructure

Several environmental processes, both occurring in the atmosphere and at the land surface, depend fundamentally on the structure of rainfall at the scale of individual raindrops. From a hydrological perspective, rainfall interception by vegetation canopies, soil erosion through raindrop impact, and the backscattering and attenuation of weather radar signals in rainfall are probably the most important of these. Detailed knowledge of the discrete microstructure of rainfall is a conditio sine qua non to understand, quantify, and ultimately predict these processes, even at much larger scales. This is the Preface to the Special Issue on “Measurement and Parameterization of Rainfall Microstructure”, containing articles that have for the most part been presented at sessions organized at the 27th and 28th European Geosciences Union (EGU) General Assemblies in Nice, France, in 2002 and 2003.