Specific attenuation-based rain-rate applicability to varying rainfall intensity in complex terrain

Recent studies have shown that the utilization of specific attenuation by a radar for rain-rate estimations R ( A ) can overcome partial beam blockage impacts by relying on radial profiles of differential phase shifts. This study applies this R ( A ) algorithm to the National Science Foundation (NSF) National Center for Atmospheric Research (NCAR) dual-polarization S-band (S-Pol) radar deployment in northwest Taiwan for the NSF-funded 2022 Prediction of Rainfall Extremes Campaign in the Pacific (PRECIP) dataset to provide reliable rain estimates, including over the mountains.

While operating for nearly 3 months, S-Pol measured multiple heavy rainfall events including isolated convective cells and widespread stratiform precipitation, thus providing an ideal dataset for evaluating R ( A ) performance sensitivities to local terrain, clutter, ray segmentation, and rain type. The R ( A ) performance improved over the more commonly used NSF NCAR hybrid rain algorithm when applying to an extreme PRECIP event after several modifications to the R ( A ) algorithm.