Linda Bogerd

and 5 more

The implementation of dual-polarization weather radars has improved the accuracy of precipitation estimates. However, identifying hydrometeor types and evaluating related algorithms remains challenging. This study introduces a novel method to evaluate hydrometeor classification (HMC) schemes using Doppler spectra from a mm-wave dual-frequency Doppler-polarimetric slanted profiler. The output of the HMC scheme is used to calculate mixing ratios that are then combined with the ARTS Microwave Single Scattering Properties Database to simulate Doppler spectra of polarimetric variables that would be measured by the profiler. Comparing these with actual profiler measurements provides valuable validation information. We have tested this method on the wradlib HMC scheme using C-band weather radar data from the Netherlands (2021–2022) and a Ka- and W-band Doppler-polarimetric profiler operating at an elevation angle of 45°. The method works well in stratiform cases, but convective cases reveal the influence of turbulence and wind variability, highlighting the need for improved approaches. Uncertainty arises from selecting specific parameterizations for the particle size distribution (PSD) and for the relationship between hydrometeor size and terminal fall velocity, as well as from the derived mixing ratios. Additionally, observing at a 45° angle complicates separating horizontal wind from hydrometeor fall velocities, though the Mie notch in the dual-wavelength ratio can be effectively used to remove the radial wind component. Our results highlight both the potential and limitations of using this profiler configuration to evaluate HMC schemes.