Profiles of raindrop size distributions as retrieved by microrain radars

Data of vertically pointing microrain radars (MRRs), located at various sites around the Baltic Sea, were analyzed for a period of several years. From the Doppler spectra profiles of drop size distributions (DSDs) are obtained. A significant height dependence of the shape of the DSDs-and thus of the Z-R relations-is observed at high rain rates. This implies, for the considered sites, that ground-based Z-R relations lead to underestimation of high rain rates by weather radars.