Rainfall Parameter Estimation from Dual-Radar Measurements Combining Reflectivity Profile and Path-integrated Attenuation

Abstract Rain rate estimation properties of multiparameter radar measurements combining radar reflectivity and microwave attenuations are studied through simulations using a two-year disdrometer dataset. In the first simulation, properties of “complete” multiparameter measurements, where error-free measurements are assumed for each radar resolution cell, are investigated. The result indicates that dual-parameter (DP) measurements provide an excellent accuracy in rain rate estimation. Most of the DP measurements possible from space are “semi-” dual-parameter (SDP) measurements, defined as DP measurements in which spatial resolution for the attenuation measurement is coarser than the resolution required for rain profiling. Considering this fact, an SDP measurement simulation is also made. The SDP measurement is an extension of the concept of the DP measurement in terms of the spatial resolution, and can provide information on raindrop size distribution (DSD) by employing a “two-scale” DSD model. It is shown...